tor-browser

ptio.c (130033B)

---

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
** File:   ptio.c
** Descritpion:  Implemenation of I/O methods for pthreads
*/

#if defined(_PR_PTHREADS)


#  include <pthread.h>
#  include <string.h> /* for memset() */
#  include <sys/types.h>
#  include <dirent.h>
#  include <fcntl.h>
#  include <unistd.h>
#  include <sys/socket.h>
#  include <sys/stat.h>
#  include <sys/uio.h>
#  include <sys/file.h>
#  include <sys/ioctl.h>
#  if defined(DARWIN)
#    include <sys/utsname.h> /* for uname */
#  endif
#  if defined(SOLARIS)
#    include <sys/filio.h> /* to pick up FIONREAD */
#  endif
#  ifdef _PR_POLL_AVAILABLE
#    include <poll.h>
#  endif
#  ifdef AIX
/* To pick up sysconf() */
#    include <unistd.h>
#    include <dlfcn.h> /* for dlopen */
#  else
/* To pick up getrlimit() etc. */
#    include <sys/time.h>
#    include <sys/resource.h>
#  endif

#  ifdef SOLARIS
/*
* Define HAVE_SENDFILEV if the system has the sendfilev() system call.
* Code built this way won't run on a system without sendfilev().
* We can define HAVE_SENDFILEV by default when the minimum release
* of Solaris that NSPR supports has sendfilev().
*/
#    ifdef HAVE_SENDFILEV

#      include <sys/sendfile.h>

#      define SOLARIS_SENDFILEV(a, b, c, d) sendfilev((a), (b), (c), (d))

#    else

#      include <dlfcn.h> /* for dlopen */

/*
* Match the definitions in <sys/sendfile.h>.
*/
typedef struct sendfilevec {
 int sfv_fd;      /* input fd */
 uint_t sfv_flag; /* flags */
 off_t sfv_off;   /* offset to start reading from */
 size_t sfv_len;  /* amount of data */
} sendfilevec_t;

#      define SFV_FD_SELF (-2)

/*
* extern ssize_t sendfilev(int, const struct sendfilevec *, int, size_t *);
*/
static ssize_t (*pt_solaris_sendfilev_fptr)() = NULL;

#      define SOLARIS_SENDFILEV(a, b, c, d) \
       (*pt_solaris_sendfilev_fptr)((a), (b), (c), (d))

#    endif /* HAVE_SENDFILEV */
#  endif   /* SOLARIS */

/*
* The send_file() system call is available in AIX 4.3.2 or later.
* If this file is compiled on an older AIX system, it attempts to
* look up the send_file symbol at run time to determine whether
* we can use the faster PR_SendFile/PR_TransmitFile implementation based on
* send_file().  On AIX 4.3.2 or later, we can safely skip this
* runtime function dispatching and just use the send_file based
* implementation.
*/
#  ifdef AIX
#    ifdef SF_CLOSE
#      define HAVE_SEND_FILE
#    endif

#    ifdef HAVE_SEND_FILE

#      define AIX_SEND_FILE(a, b, c) send_file(a, b, c)

#    else                              /* HAVE_SEND_FILE */

/*
* The following definitions match those in <sys/socket.h>
* on AIX 4.3.2.
*/

/*
* Structure for the send_file() system call
*/
struct sf_parms {
 /* --------- header parms ---------- */
 void* header_data;    /* Input/Output. Points to header buf */
 uint_t header_length; /* Input/Output. Length of the header */
 /* --------- file parms ------------ */
 int file_descriptor;            /* Input. File descriptor of the file */
 unsigned long long file_size;   /* Output. Size of the file */
 unsigned long long file_offset; /* Input/Output. Starting offset */
 long long file_bytes;           /* Input/Output. no. of bytes to send */
 /* --------- trailer parms --------- */
 void* trailer_data;    /* Input/Output. Points to trailer buf */
 uint_t trailer_length; /* Input/Output. Length of the trailer */
 /* --------- return info ----------- */
 unsigned long long bytes_sent; /* Output. no. of bytes sent */
};

/*
* Flags for the send_file() system call
*/
#      define SF_CLOSE 0x00000001      /* close the socket after completion */
#      define SF_REUSE 0x00000002      /* reuse socket. not supported */
#      define SF_DONT_CACHE 0x00000004 /* don't apply network buffer cache */
#      define SF_SYNC_CACHE 0x00000008 /* sync/update network buffer cache */

/*
* prototype: size_t send_file(int *, struct sf_parms *, uint_t);
*/
static ssize_t (*pt_aix_sendfile_fptr)() = NULL;

#      define AIX_SEND_FILE(a, b, c) (*pt_aix_sendfile_fptr)(a, b, c)

#    endif /* HAVE_SEND_FILE */
#  endif   /* AIX */

#  ifdef LINUX
#    include <sys/sendfile.h>
#  endif

#  include "primpl.h"

#  if defined(LINUX) || defined(ANDROID)
#    include <netinet/in.h>
#  endif

#  ifdef DARWIN
#    include <netinet/in.h>
#    include <netinet/ip.h>
#  endif

#  ifdef HAVE_NETINET_TCP_H
#    include <netinet/tcp.h> /* TCP_NODELAY, TCP_MAXSEG */
#  endif

#  ifdef LINUX
/* TCP_CORK is not defined in <netinet/tcp.h> on Red Hat Linux 6.0 */
#    ifndef TCP_CORK
#      define TCP_CORK 3
#    endif
#    ifndef MSG_FASTOPEN
#      define MSG_FASTOPEN 0x20000000
#    endif
#  endif

#  ifdef _PR_IPV6_V6ONLY_PROBE
static PRBool _pr_ipv6_v6only_on_by_default;
#  endif

#  if   defined(AIX4_1)
#    define _PRSelectFdSetArg_t void*
#  elif (defined(AIX) && !defined(AIX4_1)) || defined(SOLARIS) ||   \
     defined(HPUX10_30) || defined(HPUX11) || defined(LINUX) ||    \
     defined(__GNU__) || defined(__GLIBC__) || defined(FREEBSD) || \
     defined(NETBSD) || defined(OPENBSD) || defined(NTO) ||        \
     defined(DARWIN) || defined(RISCOS)
#    define _PRSelectFdSetArg_t fd_set*
#  else
#    error "Cannot determine architecture"
#  endif

#  if defined(SOLARIS)
#    ifndef PROTO_SDP
/* on solaris, SDP is a new type of protocol */
#      define PROTO_SDP 257
#    endif
#    define _PR_HAVE_SDP
#  elif defined(LINUX)
#    ifndef AF_INET_SDP
/* on linux, SDP is a new type of address family */
#      define AF_INET_SDP 27
#    endif
#    define _PR_HAVE_SDP
#  endif /* LINUX */

static PRFileDesc* pt_SetMethods(PRIntn osfd, PRDescType type,
                                PRBool isAcceptedSocket, PRBool imported);

static PRLock* _pr_flock_lock;  /* For PR_LockFile() etc. */
static PRCondVar* _pr_flock_cv; /* For PR_LockFile() etc. */
static PRLock* _pr_rename_lock; /* For PR_Rename() */

/**************************************************************************/

/* These two functions are only used in assertions. */
#  if defined(DEBUG)

PRBool IsValidNetAddr(const PRNetAddr* addr) {
 if ((addr != NULL) && (addr->raw.family != AF_UNIX) &&
     (addr->raw.family != PR_AF_INET6) && (addr->raw.family != AF_INET)) {
   return PR_FALSE;
 }
 return PR_TRUE;
}

static PRBool IsValidNetAddrLen(const PRNetAddr* addr, PRInt32 addr_len) {
 /*
  * The definition of the length of a Unix domain socket address
  * is not uniform, so we don't check it.
  */
 if ((addr != NULL) && (addr->raw.family != AF_UNIX) &&
     (PR_NETADDR_SIZE(addr) != addr_len)) {
#    if defined(LINUX) && __GLIBC__ == 2 && __GLIBC_MINOR__ == 1
   /*
    * In glibc 2.1, struct sockaddr_in6 is 24 bytes.  In glibc 2.2
    * and in the 2.4 kernel, struct sockaddr_in6 has the scope_id
    * field and is 28 bytes.  It is possible for socket functions
    * to return an addr_len greater than sizeof(struct sockaddr_in6).
    * We need to allow that.  (Bugzilla bug #77264)
    */
   if ((PR_AF_INET6 == addr->raw.family) && (sizeof(addr->ipv6) == addr_len)) {
     return PR_TRUE;
   }
#    endif
   return PR_FALSE;
 }
 return PR_TRUE;
}

#  endif /* DEBUG */

/*****************************************************************************/
/************************* I/O Continuation machinery ************************/
/*****************************************************************************/

/*
* The polling interval defines the maximum amount of time that a thread
* might hang up before an interrupt is noticed.
*/
#  define PT_DEFAULT_POLL_MSEC 5000

/*
* pt_SockLen is the type for the length of a socket address
* structure, used in the address length argument to bind,
* connect, accept, getsockname, getpeername, etc.  Posix.1g
* defines this type as socklen_t.  It is size_t or int on
* most current systems.
*/
#  if defined(HAVE_SOCKLEN_T) || (defined(__GLIBC__) && __GLIBC__ >= 2)
typedef socklen_t pt_SockLen;
#  elif (defined(AIX) && !defined(AIX4_1))
typedef PRSize pt_SockLen;
#  else
typedef PRIntn pt_SockLen;
#  endif

typedef struct pt_Continuation pt_Continuation;
typedef PRBool (*ContinuationFn)(pt_Continuation* op, PRInt16 revents);

typedef enum pr_ContuationStatus {
 pt_continuation_pending,
 pt_continuation_done
} pr_ContuationStatus;

struct pt_Continuation {
 /* The building of the continuation operation */
 ContinuationFn function; /* what function to continue */
 union {
   PRIntn osfd;
 } arg1; /* #1 - the op's fd */
 union {
   void* buffer;
 } arg2; /* #2 - primary transfer buffer */
 union {
   PRSize amount;        /* #3 - size of 'buffer', or */
   pt_SockLen* addr_len; /*    - length of address */
#  ifdef HPUX11
   /*
    * For sendfile()
    */
   struct file_spec {
     off_t offset;   /* offset in file to send */
     size_t nbytes;  /* length of file data to send */
     size_t st_size; /* file size */
   } file_spec;
#  endif
 } arg3;
 union {
   PRIntn flags;
 } arg4; /* #4 - read/write flags */
 union {
   PRNetAddr* addr;
 } arg5; /* #5 - send/recv address */

#  ifdef HPUX11
 /*
  * For sendfile()
  */
 int filedesc;       /* descriptor of file to send */
 int nbytes_to_send; /* size of header and file */
#  endif              /* HPUX11 */

#  ifdef SOLARIS
 /*
  * For sendfilev()
  */
 int nbytes_to_send; /* size of header and file */
#  endif              /* SOLARIS */

#  ifdef LINUX
 /*
  * For sendfile()
  */
 int in_fd; /* descriptor of file to send */
 off_t offset;
 size_t count;
#  endif /* LINUX */

 PRIntervalTime timeout; /* client (relative) timeout */

 PRInt16 event; /* flags for poll()'s events */

 /*
 ** The representation and notification of the results of the operation.
 ** These function can either return an int return code or a pointer to
 ** some object.
 */
 union {
   PRSize code;
   void* object;
 } result;

 PRIntn syserrno;            /* in case it failed, why (errno) */
 pr_ContuationStatus status; /* the status of the operation */
};

#  if defined(DEBUG)

PTDebug pt_debug; /* this is shared between several modules */

PR_IMPLEMENT(void) PT_FPrintStats(PRFileDesc* debug_out, const char* msg) {
 PTDebug stats;
 char buffer[100];
 PRExplodedTime tod;
 PRInt64 elapsed, aMil;
 stats = pt_debug; /* a copy */
 PR_ExplodeTime(stats.timeStarted, PR_LocalTimeParameters, &tod);
 (void)PR_FormatTime(buffer, sizeof(buffer), "%T", &tod);

 LL_SUB(elapsed, PR_Now(), stats.timeStarted);
 LL_I2L(aMil, 1000000);
 LL_DIV(elapsed, elapsed, aMil);

 if (NULL != msg) {
   PR_fprintf(debug_out, "%s", msg);
 }
 PR_fprintf(debug_out, "\tstarted: %s[%lld]\n", buffer, elapsed);
 PR_fprintf(debug_out, "\tlocks [created: %u, destroyed: %u]\n",
            stats.locks_created, stats.locks_destroyed);
 PR_fprintf(debug_out, "\tlocks [acquired: %u, released: %u]\n",
            stats.locks_acquired, stats.locks_released);
 PR_fprintf(debug_out, "\tcvars [created: %u, destroyed: %u]\n",
            stats.cvars_created, stats.cvars_destroyed);
 PR_fprintf(debug_out, "\tcvars [notified: %u, delayed_delete: %u]\n",
            stats.cvars_notified, stats.delayed_cv_deletes);
} /* PT_FPrintStats */

#  else

PR_IMPLEMENT(void) PT_FPrintStats(PRFileDesc* debug_out, const char* msg) {
 /* do nothing */
} /* PT_FPrintStats */

#  endif /* DEBUG */


static void pt_poll_now(pt_Continuation* op) {
 PRInt32 msecs;
 PRIntervalTime epoch, now, elapsed, remaining;
 PRBool wait_for_remaining;
 PRThread* self = PR_GetCurrentThread();

 PR_ASSERT(PR_INTERVAL_NO_WAIT != op->timeout);

 switch (op->timeout) {
   case PR_INTERVAL_NO_TIMEOUT:
     msecs = PT_DEFAULT_POLL_MSEC;
     do {
       PRIntn rv;
       struct pollfd tmp_pfd;

       tmp_pfd.revents = 0;
       tmp_pfd.fd = op->arg1.osfd;
       tmp_pfd.events = op->event;

       rv = poll(&tmp_pfd, 1, msecs);

       if (_PT_THREAD_INTERRUPTED(self)) {
         self->state &= ~PT_THREAD_ABORTED;
         op->result.code = -1;
         op->syserrno = EINTR;
         op->status = pt_continuation_done;
         return;
       }

       if ((-1 == rv) && ((errno == EINTR) || (errno == EAGAIN))) {
         continue; /* go around the loop again */
       }

       if (rv > 0) {
         PRInt16 events = tmp_pfd.events;
         PRInt16 revents = tmp_pfd.revents;

         if ((revents & POLLNVAL) /* busted in all cases */
             || ((events & POLLOUT) && (revents & POLLHUP)))
         /* write op & hup */
         {
           op->result.code = -1;
           if (POLLNVAL & revents) {
             op->syserrno = EBADF;
           } else if (POLLHUP & revents) {
             op->syserrno = EPIPE;
           }
           op->status = pt_continuation_done;
         } else {
           if (op->function(op, revents)) {
             op->status = pt_continuation_done;
           }
         }
       } else if (rv == -1) {
         op->result.code = -1;
         op->syserrno = errno;
         op->status = pt_continuation_done;
       }
       /* else, poll timed out */
     } while (pt_continuation_done != op->status);
     break;
   default:
     now = epoch = PR_IntervalNow();
     remaining = op->timeout;
     do {
       PRIntn rv;
       struct pollfd tmp_pfd;

       tmp_pfd.revents = 0;
       tmp_pfd.fd = op->arg1.osfd;
       tmp_pfd.events = op->event;

       wait_for_remaining = PR_TRUE;
       msecs = (PRInt32)PR_IntervalToMilliseconds(remaining);
       if (msecs > PT_DEFAULT_POLL_MSEC) {
         wait_for_remaining = PR_FALSE;
         msecs = PT_DEFAULT_POLL_MSEC;
       }
       rv = poll(&tmp_pfd, 1, msecs);

       if (_PT_THREAD_INTERRUPTED(self)) {
         self->state &= ~PT_THREAD_ABORTED;
         op->result.code = -1;
         op->syserrno = EINTR;
         op->status = pt_continuation_done;
         return;
       }

       if (rv > 0) {
         PRInt16 events = tmp_pfd.events;
         PRInt16 revents = tmp_pfd.revents;

         if ((revents & POLLNVAL) /* busted in all cases */
             || ((events & POLLOUT) && (revents & POLLHUP)))
         /* write op & hup */
         {
           op->result.code = -1;
           if (POLLNVAL & revents) {
             op->syserrno = EBADF;
           } else if (POLLHUP & revents) {
             op->syserrno = EPIPE;
           }
           op->status = pt_continuation_done;
         } else {
           if (op->function(op, revents)) {
             op->status = pt_continuation_done;
           }
         }
       } else if ((rv == 0) || ((errno == EINTR) || (errno == EAGAIN))) {
         if (rv == 0) /* poll timed out */
         {
           if (wait_for_remaining) {
             now += remaining;
           } else {
             now += PR_MillisecondsToInterval(msecs);
           }
         } else {
           now = PR_IntervalNow();
         }
         elapsed = (PRIntervalTime)(now - epoch);
         if (elapsed >= op->timeout) {
           op->result.code = -1;
           op->syserrno = ETIMEDOUT;
           op->status = pt_continuation_done;
         } else {
           remaining = op->timeout - elapsed;
         }
       } else {
         op->result.code = -1;
         op->syserrno = errno;
         op->status = pt_continuation_done;
       }
     } while (pt_continuation_done != op->status);
     break;
 }

} /* pt_poll_now */

static PRIntn pt_Continue(pt_Continuation* op) {
 op->status = pt_continuation_pending; /* set default value */
 /*
  * let each thread call poll directly
  */
 pt_poll_now(op);
 PR_ASSERT(pt_continuation_done == op->status);
 return op->result.code;
} /* pt_Continue */

/*****************************************************************************/
/*********************** specific continuation functions *********************/
/*****************************************************************************/
static PRBool pt_connect_cont(pt_Continuation* op, PRInt16 revents) {
 op->syserrno = _MD_unix_get_nonblocking_connect_error(op->arg1.osfd);
 if (op->syserrno != 0) {
   op->result.code = -1;
 } else {
   op->result.code = 0;
 }
 return PR_TRUE; /* this one is cooked */
} /* pt_connect_cont */

static PRBool pt_accept_cont(pt_Continuation* op, PRInt16 revents) {
 op->syserrno = 0;
 op->result.code = accept(op->arg1.osfd, op->arg2.buffer, op->arg3.addr_len);
 if (-1 == op->result.code) {
   op->syserrno = errno;
   if (EWOULDBLOCK == errno || EAGAIN == errno || ECONNABORTED == errno) {
     return PR_FALSE; /* do nothing - this one ain't finished */
   }
 }
 return PR_TRUE;
} /* pt_accept_cont */

static PRBool pt_read_cont(pt_Continuation* op, PRInt16 revents) {
 /*
  * Any number of bytes will complete the operation. It need
  * not (and probably will not) satisfy the request. The only
  * error we continue is EWOULDBLOCK|EAGAIN.
  */
 op->result.code = read(op->arg1.osfd, op->arg2.buffer, op->arg3.amount);
 op->syserrno = errno;
 return ((-1 == op->result.code) &&
         (EWOULDBLOCK == op->syserrno || EAGAIN == op->syserrno))
            ? PR_FALSE
            : PR_TRUE;
} /* pt_read_cont */

static PRBool pt_recv_cont(pt_Continuation* op, PRInt16 revents) {
 /*
  * Any number of bytes will complete the operation. It need
  * not (and probably will not) satisfy the request. The only
  * error we continue is EWOULDBLOCK|EAGAIN.
  */
#  if defined(SOLARIS)
 if (0 == op->arg4.flags)
   op->result.code = read(op->arg1.osfd, op->arg2.buffer, op->arg3.amount);
 else
   op->result.code =
       recv(op->arg1.osfd, op->arg2.buffer, op->arg3.amount, op->arg4.flags);
#  else
 op->result.code =
     recv(op->arg1.osfd, op->arg2.buffer, op->arg3.amount, op->arg4.flags);
#  endif
 op->syserrno = errno;
 return ((-1 == op->result.code) &&
         (EWOULDBLOCK == op->syserrno || EAGAIN == op->syserrno))
            ? PR_FALSE
            : PR_TRUE;
} /* pt_recv_cont */

static PRBool pt_send_cont(pt_Continuation* op, PRInt16 revents) {
 PRIntn bytes;
#  if defined(SOLARIS)
 PRInt32 tmp_amount = op->arg3.amount;
#  endif
 /*
  * We want to write the entire amount out, no matter how many
  * tries it takes. Keep advancing the buffer and the decrementing
  * the amount until the amount goes away. Return the total bytes
  * (which should be the original amount) when finished (or an
  * error).
  */
#  if defined(SOLARIS)
retry:
 bytes = write(op->arg1.osfd, op->arg2.buffer, tmp_amount);
#  else
 bytes = send(op->arg1.osfd, op->arg2.buffer, op->arg3.amount, op->arg4.flags);
#  endif
 op->syserrno = errno;

#  if defined(SOLARIS)
 /*
  * The write system call has been reported to return the ERANGE error
  * on occasion. Try to write in smaller chunks to workaround this bug.
  */
 if ((bytes == -1) && (op->syserrno == ERANGE)) {
   if (tmp_amount > 1) {
     tmp_amount = tmp_amount / 2; /* half the bytes */
     goto retry;
   }
 }
#  endif

 if (bytes >= 0) /* this is progress */
 {
   char* bp = (char*)op->arg2.buffer;
   bp += bytes; /* adjust the buffer pointer */
   op->arg2.buffer = bp;
   op->result.code += bytes; /* accumulate the number sent */
   op->arg3.amount -= bytes; /* and reduce the required count */
   return (0 == op->arg3.amount) ? PR_TRUE : PR_FALSE;
 }
 if ((EWOULDBLOCK != op->syserrno) && (EAGAIN != op->syserrno)) {
   op->result.code = -1;
   return PR_TRUE;
 } else {
   return PR_FALSE;
 }
} /* pt_send_cont */

static PRBool pt_write_cont(pt_Continuation* op, PRInt16 revents) {
 PRIntn bytes;
 /*
  * We want to write the entire amount out, no matter how many
  * tries it takes. Keep advancing the buffer and the decrementing
  * the amount until the amount goes away. Return the total bytes
  * (which should be the original amount) when finished (or an
  * error).
  */
 bytes = write(op->arg1.osfd, op->arg2.buffer, op->arg3.amount);
 op->syserrno = errno;
 if (bytes >= 0) /* this is progress */
 {
   char* bp = (char*)op->arg2.buffer;
   bp += bytes; /* adjust the buffer pointer */
   op->arg2.buffer = bp;
   op->result.code += bytes; /* accumulate the number sent */
   op->arg3.amount -= bytes; /* and reduce the required count */
   return (0 == op->arg3.amount) ? PR_TRUE : PR_FALSE;
 }
 if ((EWOULDBLOCK != op->syserrno) && (EAGAIN != op->syserrno)) {
   op->result.code = -1;
   return PR_TRUE;
 } else {
   return PR_FALSE;
 }
} /* pt_write_cont */

static PRBool pt_writev_cont(pt_Continuation* op, PRInt16 revents) {
 PRIntn bytes;
 struct iovec* iov = (struct iovec*)op->arg2.buffer;
 /*
  * Same rules as write, but continuing seems to be a bit more
  * complicated. As the number of bytes sent grows, we have to
  * redefine the vector we're pointing at. We might have to
  * modify an individual vector parms or we might have to eliminate
  * a pair altogether.
  */
 bytes = writev(op->arg1.osfd, iov, op->arg3.amount);
 op->syserrno = errno;
 if (bytes >= 0) /* this is progress */
 {
   PRIntn iov_index;
   op->result.code += bytes; /* accumulate the number sent */
   for (iov_index = 0; iov_index < op->arg3.amount; ++iov_index) {
     /* how much progress did we make in the i/o vector? */
     if (bytes < iov[iov_index].iov_len) {
       /* this element's not done yet */
       char** bp = (char**)&(iov[iov_index].iov_base);
       iov[iov_index].iov_len -= bytes; /* there's that much left */
       *bp += bytes;                    /* starting there */
       break;                           /* go off and do that */
     }
     bytes -= iov[iov_index].iov_len; /* that element's consumed */
   }
   op->arg2.buffer = &iov[iov_index]; /* new start of array */
   op->arg3.amount -= iov_index;      /* and array length */
   return (0 == op->arg3.amount) ? PR_TRUE : PR_FALSE;
 }
 if ((EWOULDBLOCK != op->syserrno) && (EAGAIN != op->syserrno)) {
   op->result.code = -1;
   return PR_TRUE;
 } else {
   return PR_FALSE;
 }
} /* pt_writev_cont */

static PRBool pt_sendto_cont(pt_Continuation* op, PRInt16 revents) {
 PRIntn bytes =
     sendto(op->arg1.osfd, op->arg2.buffer, op->arg3.amount, op->arg4.flags,
            (struct sockaddr*)op->arg5.addr, PR_NETADDR_SIZE(op->arg5.addr));
 op->syserrno = errno;
 if (bytes >= 0) /* this is progress */
 {
   char* bp = (char*)op->arg2.buffer;
   bp += bytes; /* adjust the buffer pointer */
   op->arg2.buffer = bp;
   op->result.code += bytes; /* accumulate the number sent */
   op->arg3.amount -= bytes; /* and reduce the required count */
   return (0 == op->arg3.amount) ? PR_TRUE : PR_FALSE;
 }
 if ((EWOULDBLOCK != op->syserrno) && (EAGAIN != op->syserrno)) {
   op->result.code = -1;
   return PR_TRUE;
 } else {
   return PR_FALSE;
 }
} /* pt_sendto_cont */

static PRBool pt_recvfrom_cont(pt_Continuation* op, PRInt16 revents) {
 pt_SockLen addr_len = sizeof(PRNetAddr);
 op->result.code =
     recvfrom(op->arg1.osfd, op->arg2.buffer, op->arg3.amount, op->arg4.flags,
              (struct sockaddr*)op->arg5.addr, &addr_len);
 op->syserrno = errno;
 return ((-1 == op->result.code) &&
         (EWOULDBLOCK == op->syserrno || EAGAIN == op->syserrno))
            ? PR_FALSE
            : PR_TRUE;
} /* pt_recvfrom_cont */

#  ifdef AIX
static PRBool pt_aix_sendfile_cont(pt_Continuation* op, PRInt16 revents) {
 struct sf_parms* sf_struct = (struct sf_parms*)op->arg2.buffer;
 ssize_t rv;
 unsigned long long saved_file_offset;
 long long saved_file_bytes;

 saved_file_offset = sf_struct->file_offset;
 saved_file_bytes = sf_struct->file_bytes;
 sf_struct->bytes_sent = 0;

 if ((sf_struct->file_bytes > 0) && (sf_struct->file_size > 0))
   PR_ASSERT((sf_struct->file_bytes + sf_struct->file_offset) <=
             sf_struct->file_size);
 rv = AIX_SEND_FILE(&op->arg1.osfd, sf_struct, op->arg4.flags);
 op->syserrno = errno;

 if (rv != -1) {
   op->result.code += sf_struct->bytes_sent;
   /*
    * A bug in AIX 4.3.2 prevents the 'file_bytes' field from
    * being updated. So, 'file_bytes' is maintained by NSPR to
    * avoid conflict when this bug is fixed in AIX, in the future.
    */
   if (saved_file_bytes != -1) {
     saved_file_bytes -= (sf_struct->file_offset - saved_file_offset);
   }
   sf_struct->file_bytes = saved_file_bytes;
 } else if (op->syserrno != EWOULDBLOCK && op->syserrno != EAGAIN) {
   op->result.code = -1;
 } else {
   return PR_FALSE;
 }

 if (rv == 1) { /* more data to send */
   return PR_FALSE;
 }

 return PR_TRUE;
}
#  endif /* AIX */

#  ifdef HPUX11
static PRBool pt_hpux_sendfile_cont(pt_Continuation* op, PRInt16 revents) {
 struct iovec* hdtrl = (struct iovec*)op->arg2.buffer;
 int count;

 count = sendfile(op->arg1.osfd, op->filedesc, op->arg3.file_spec.offset,
                  op->arg3.file_spec.nbytes, hdtrl, op->arg4.flags);
 PR_ASSERT(count <= op->nbytes_to_send);
 op->syserrno = errno;

 if (count != -1) {
   op->result.code += count;
 } else if (op->syserrno != EWOULDBLOCK && op->syserrno != EAGAIN) {
   op->result.code = -1;
 } else {
   return PR_FALSE;
 }
 if (count != -1 && count < op->nbytes_to_send) {
   if (count < hdtrl[0].iov_len) {
     /* header not sent */

     hdtrl[0].iov_base = ((char*)hdtrl[0].iov_base) + count;
     hdtrl[0].iov_len -= count;

   } else if (count < (hdtrl[0].iov_len + op->arg3.file_spec.nbytes)) {
     /* header sent, file not sent */
     PRUint32 file_nbytes_sent = count - hdtrl[0].iov_len;

     hdtrl[0].iov_base = NULL;
     hdtrl[0].iov_len = 0;

     op->arg3.file_spec.offset += file_nbytes_sent;
     op->arg3.file_spec.nbytes -= file_nbytes_sent;
   } else if (count < (hdtrl[0].iov_len + op->arg3.file_spec.nbytes +
                       hdtrl[1].iov_len)) {
     PRUint32 trailer_nbytes_sent =
         count - (hdtrl[0].iov_len + op->arg3.file_spec.nbytes);

     /* header sent, file sent, trailer not sent */

     hdtrl[0].iov_base = NULL;
     hdtrl[0].iov_len = 0;
     /*
      * set file offset and len so that no more file data is
      * sent
      */
     op->arg3.file_spec.offset = op->arg3.file_spec.st_size;
     op->arg3.file_spec.nbytes = 0;

     hdtrl[1].iov_base = ((char*)hdtrl[1].iov_base) + trailer_nbytes_sent;
     hdtrl[1].iov_len -= trailer_nbytes_sent;
   }
   op->nbytes_to_send -= count;
   return PR_FALSE;
 }

 return PR_TRUE;
}
#  endif /* HPUX11 */

#  ifdef SOLARIS
static PRBool pt_solaris_sendfile_cont(pt_Continuation* op, PRInt16 revents) {
 struct sendfilevec* vec = (struct sendfilevec*)op->arg2.buffer;
 size_t xferred;
 ssize_t count;

 count = SOLARIS_SENDFILEV(op->arg1.osfd, vec, op->arg3.amount, &xferred);
 op->syserrno = errno;
 PR_ASSERT((count == -1) || (count == xferred));

 if (count == -1) {
   if (op->syserrno != EWOULDBLOCK && op->syserrno != EAGAIN &&
       op->syserrno != EINTR) {
     op->result.code = -1;
     return PR_TRUE;
   }
   count = xferred;
 } else if (count == 0) {
   /*
    * We are now at EOF. The file was truncated. Solaris sendfile is
    * supposed to return 0 and no error in this case, though some versions
    * may return -1 and EINVAL .
    */
   op->result.code = -1;
   op->syserrno = 0; /* will be treated as EOF */
   return PR_TRUE;
 }
 PR_ASSERT(count <= op->nbytes_to_send);

 op->result.code += count;
 if (count < op->nbytes_to_send) {
   op->nbytes_to_send -= count;

   while (count >= vec->sfv_len) {
     count -= vec->sfv_len;
     vec++;
     op->arg3.amount--;
   }
   PR_ASSERT(op->arg3.amount > 0);

   vec->sfv_off += count;
   vec->sfv_len -= count;
   PR_ASSERT(vec->sfv_len > 0);
   op->arg2.buffer = vec;

   return PR_FALSE;
 }

 return PR_TRUE;
}
#  endif /* SOLARIS */

#  ifdef LINUX
static PRBool pt_linux_sendfile_cont(pt_Continuation* op, PRInt16 revents) {
 ssize_t rv;
 off_t oldoffset;

 oldoffset = op->offset;
 rv = sendfile(op->arg1.osfd, op->in_fd, &op->offset, op->count);
 op->syserrno = errno;

 if (rv == -1) {
   if (op->syserrno != EWOULDBLOCK && op->syserrno != EAGAIN) {
     op->result.code = -1;
     return PR_TRUE;
   }
   rv = 0;
 }
 PR_ASSERT(rv == op->offset - oldoffset);
 op->result.code += rv;
 if (rv < op->count) {
   op->count -= rv;
   return PR_FALSE;
 }
 return PR_TRUE;
}
#  endif /* LINUX */

void _PR_InitIO(void) {
#  if defined(DEBUG)
 memset(&pt_debug, 0, sizeof(PTDebug));
 pt_debug.timeStarted = PR_Now();
#  endif

 _pr_flock_lock = PR_NewLock();
 PR_ASSERT(NULL != _pr_flock_lock);
 _pr_flock_cv = PR_NewCondVar(_pr_flock_lock);
 PR_ASSERT(NULL != _pr_flock_cv);
 _pr_rename_lock = PR_NewLock();
 PR_ASSERT(NULL != _pr_rename_lock);

 _PR_InitFdCache(); /* do that */

 _pr_stdin = pt_SetMethods(0, PR_DESC_FILE, PR_FALSE, PR_TRUE);
 _pr_stdout = pt_SetMethods(1, PR_DESC_FILE, PR_FALSE, PR_TRUE);
 _pr_stderr = pt_SetMethods(2, PR_DESC_FILE, PR_FALSE, PR_TRUE);
 PR_ASSERT(_pr_stdin && _pr_stdout && _pr_stderr);

#  ifdef _PR_IPV6_V6ONLY_PROBE
 /* In Mac OS X v10.3 Panther Beta the IPV6_V6ONLY socket option
  * is turned on by default, contrary to what RFC 3493, Section
  * 5.3 says.  So we have to turn it off.  Find out whether we
  * are running on such a system.
  */
 {
   int osfd;
   osfd = socket(AF_INET6, SOCK_STREAM, 0);
   if (osfd != -1) {
     int on;
     socklen_t optlen = sizeof(on);
     if (getsockopt(osfd, IPPROTO_IPV6, IPV6_V6ONLY, &on, &optlen) == 0) {
       _pr_ipv6_v6only_on_by_default = on;
     }
     close(osfd);
   }
 }
#  endif
} /* _PR_InitIO */

void _PR_CleanupIO(void) {
 _PR_Putfd(_pr_stdin);
 _pr_stdin = NULL;
 _PR_Putfd(_pr_stdout);
 _pr_stdout = NULL;
 _PR_Putfd(_pr_stderr);
 _pr_stderr = NULL;

 _PR_CleanupFdCache();

 if (_pr_flock_cv) {
   PR_DestroyCondVar(_pr_flock_cv);
   _pr_flock_cv = NULL;
 }
 if (_pr_flock_lock) {
   PR_DestroyLock(_pr_flock_lock);
   _pr_flock_lock = NULL;
 }
 if (_pr_rename_lock) {
   PR_DestroyLock(_pr_rename_lock);
   _pr_rename_lock = NULL;
 }
} /* _PR_CleanupIO */

PR_IMPLEMENT(PRFileDesc*) PR_GetSpecialFD(PRSpecialFD osfd) {
 PRFileDesc* result = NULL;
 PR_ASSERT(osfd >= PR_StandardInput && osfd <= PR_StandardError);

 if (!_pr_initialized) {
   _PR_ImplicitInitialization();
 }

 switch (osfd) {
   case PR_StandardInput:
     result = _pr_stdin;
     break;
   case PR_StandardOutput:
     result = _pr_stdout;
     break;
   case PR_StandardError:
     result = _pr_stderr;
     break;
   default:
     (void)PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
 }
 return result;
} /* PR_GetSpecialFD */

/*****************************************************************************/
/***************************** I/O private methods ***************************/
/*****************************************************************************/

static PRBool pt_TestAbort(void) {
 PRThread* me = PR_GetCurrentThread();
 if (_PT_THREAD_INTERRUPTED(me)) {
   PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0);
   me->state &= ~PT_THREAD_ABORTED;
   return PR_TRUE;
 }
 return PR_FALSE;
} /* pt_TestAbort */

static void pt_MapError(void (*mapper)(PRIntn), PRIntn syserrno) {
 switch (syserrno) {
   case EINTR:
     PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0);
     break;
   case ETIMEDOUT:
     PR_SetError(PR_IO_TIMEOUT_ERROR, 0);
     break;
   default:
     mapper(syserrno);
 }
} /* pt_MapError */

static PRStatus pt_Close(PRFileDesc* fd) {
 if ((NULL == fd) || (NULL == fd->secret) ||
     ((_PR_FILEDESC_OPEN != fd->secret->state) &&
      (_PR_FILEDESC_CLOSED != fd->secret->state))) {
   PR_SetError(PR_BAD_DESCRIPTOR_ERROR, 0);
   return PR_FAILURE;
 }
 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 if (_PR_FILEDESC_OPEN == fd->secret->state) {
   if (-1 == close(fd->secret->md.osfd)) {
     pt_MapError(_PR_MD_MAP_CLOSE_ERROR, errno);
     return PR_FAILURE;
   }
   fd->secret->state = _PR_FILEDESC_CLOSED;
 }
 _PR_Putfd(fd);
 return PR_SUCCESS;
} /* pt_Close */

static PRInt32 pt_Read(PRFileDesc* fd, void* buf, PRInt32 amount) {
 PRInt32 syserrno, bytes = -1;

 if (pt_TestAbort()) {
   return bytes;
 }

 bytes = read(fd->secret->md.osfd, buf, amount);
 syserrno = errno;

 if ((bytes == -1) && (syserrno == EWOULDBLOCK || syserrno == EAGAIN) &&
     (!fd->secret->nonblocking)) {
   pt_Continuation op;
   op.arg1.osfd = fd->secret->md.osfd;
   op.arg2.buffer = buf;
   op.arg3.amount = amount;
   op.timeout = PR_INTERVAL_NO_TIMEOUT;
   op.function = pt_read_cont;
   op.event = POLLIN | POLLPRI;
   bytes = pt_Continue(&op);
   syserrno = op.syserrno;
 }
 if (bytes < 0) {
   pt_MapError(_PR_MD_MAP_READ_ERROR, syserrno);
 }
 return bytes;
} /* pt_Read */

static PRInt32 pt_Write(PRFileDesc* fd, const void* buf, PRInt32 amount) {
 PRInt32 syserrno, bytes = -1;
 PRBool fNeedContinue = PR_FALSE;

 if (pt_TestAbort()) {
   return bytes;
 }

 bytes = write(fd->secret->md.osfd, buf, amount);
 syserrno = errno;

 if ((bytes >= 0) && (bytes < amount) && (!fd->secret->nonblocking)) {
   buf = (char*)buf + bytes;
   amount -= bytes;
   fNeedContinue = PR_TRUE;
 }
 if ((bytes == -1) && (syserrno == EWOULDBLOCK || syserrno == EAGAIN) &&
     (!fd->secret->nonblocking)) {
   bytes = 0;
   fNeedContinue = PR_TRUE;
 }

 if (fNeedContinue == PR_TRUE) {
   pt_Continuation op;
   op.arg1.osfd = fd->secret->md.osfd;
   op.arg2.buffer = (void*)buf;
   op.arg3.amount = amount;
   op.timeout = PR_INTERVAL_NO_TIMEOUT;
   op.result.code = bytes; /* initialize the number sent */
   op.function = pt_write_cont;
   op.event = POLLOUT | POLLPRI;
   bytes = pt_Continue(&op);
   syserrno = op.syserrno;
 }
 if (bytes == -1) {
   pt_MapError(_PR_MD_MAP_WRITE_ERROR, syserrno);
 }
 return bytes;
} /* pt_Write */

static PRInt32 pt_Writev(PRFileDesc* fd, const PRIOVec* iov, PRInt32 iov_len,
                        PRIntervalTime timeout) {
 PRIntn iov_index;
 PRBool fNeedContinue = PR_FALSE;
 PRInt32 syserrno, bytes, rv = -1;
 struct iovec osiov_local[PR_MAX_IOVECTOR_SIZE], *osiov;
 int osiov_len;

 if (pt_TestAbort()) {
   return rv;
 }

 /* Ensured by PR_Writev */
 PR_ASSERT(iov_len <= PR_MAX_IOVECTOR_SIZE);

 /*
  * We can't pass iov to writev because PRIOVec and struct iovec
  * may not be binary compatible.  Make osiov a copy of iov and
  * pass osiov to writev.  We can modify osiov if we need to
  * continue the operation.
  */
 osiov = osiov_local;
 osiov_len = iov_len;
 for (iov_index = 0; iov_index < osiov_len; iov_index++) {
   osiov[iov_index].iov_base = iov[iov_index].iov_base;
   osiov[iov_index].iov_len = iov[iov_index].iov_len;
 }

 rv = bytes = writev(fd->secret->md.osfd, osiov, osiov_len);
 syserrno = errno;

 if (!fd->secret->nonblocking) {
   if (bytes >= 0) {
     /*
      * If we moved some bytes, how does that implicate the
      * i/o vector list?  In other words, exactly where are
      * we within that array?  What are the parameters for
      * resumption?  Maybe we're done!
      */
     for (; osiov_len > 0; osiov++, osiov_len--) {
       if (bytes < osiov->iov_len) {
         /* this one's not done yet */
         osiov->iov_base = (char*)osiov->iov_base + bytes;
         osiov->iov_len -= bytes;
         break; /* go off and do that */
       }
       bytes -= osiov->iov_len; /* this one's done cooked */
     }
     PR_ASSERT(osiov_len > 0 || bytes == 0);
     if (osiov_len > 0) {
       if (PR_INTERVAL_NO_WAIT == timeout) {
         rv = -1;
         syserrno = ETIMEDOUT;
       } else {
         fNeedContinue = PR_TRUE;
       }
     }
   } else if (syserrno == EWOULDBLOCK || syserrno == EAGAIN) {
     if (PR_INTERVAL_NO_WAIT == timeout) {
       syserrno = ETIMEDOUT;
     } else {
       rv = 0;
       fNeedContinue = PR_TRUE;
     }
   }
 }

 if (fNeedContinue == PR_TRUE) {
   pt_Continuation op;

   op.arg1.osfd = fd->secret->md.osfd;
   op.arg2.buffer = (void*)osiov;
   op.arg3.amount = osiov_len;
   op.timeout = timeout;
   op.result.code = rv;
   op.function = pt_writev_cont;
   op.event = POLLOUT | POLLPRI;
   rv = pt_Continue(&op);
   syserrno = op.syserrno;
 }
 if (rv == -1) {
   pt_MapError(_PR_MD_MAP_WRITEV_ERROR, syserrno);
 }
 return rv;
} /* pt_Writev */

static PRInt32 pt_Seek(PRFileDesc* fd, PRInt32 offset, PRSeekWhence whence) {
 return _PR_MD_LSEEK(fd, offset, whence);
} /* pt_Seek */

static PRInt64 pt_Seek64(PRFileDesc* fd, PRInt64 offset, PRSeekWhence whence) {
 return _PR_MD_LSEEK64(fd, offset, whence);
} /* pt_Seek64 */

static PRInt32 pt_Available_f(PRFileDesc* fd) {
 PRInt32 result, cur, end;

 cur = _PR_MD_LSEEK(fd, 0, PR_SEEK_CUR);

 if (cur >= 0) {
   end = _PR_MD_LSEEK(fd, 0, PR_SEEK_END);
 }

 if ((cur < 0) || (end < 0)) {
   return -1;
 }

 result = end - cur;
 _PR_MD_LSEEK(fd, cur, PR_SEEK_SET);

 return result;
} /* pt_Available_f */

static PRInt64 pt_Available64_f(PRFileDesc* fd) {
 PRInt64 result, cur, end;
 PRInt64 minus_one;

 LL_I2L(minus_one, -1);
 cur = _PR_MD_LSEEK64(fd, LL_ZERO, PR_SEEK_CUR);

 if (LL_GE_ZERO(cur)) {
   end = _PR_MD_LSEEK64(fd, LL_ZERO, PR_SEEK_END);
 }

 if (!LL_GE_ZERO(cur) || !LL_GE_ZERO(end)) {
   return minus_one;
 }

 LL_SUB(result, end, cur);
 (void)_PR_MD_LSEEK64(fd, cur, PR_SEEK_SET);

 return result;
} /* pt_Available64_f */

static PRInt32 pt_Available_s(PRFileDesc* fd) {
 PRInt32 rv, bytes = -1;
 if (pt_TestAbort()) {
   return bytes;
 }

 rv = ioctl(fd->secret->md.osfd, FIONREAD, &bytes);

 if (rv == -1) {
   pt_MapError(_PR_MD_MAP_SOCKETAVAILABLE_ERROR, errno);
 }
 return bytes;
} /* pt_Available_s */

static PRInt64 pt_Available64_s(PRFileDesc* fd) {
 PRInt64 rv;
 LL_I2L(rv, pt_Available_s(fd));
 return rv;
} /* pt_Available64_s */

static PRStatus pt_FileInfo(PRFileDesc* fd, PRFileInfo* info) {
 PRInt32 rv = _PR_MD_GETOPENFILEINFO(fd, info);
 return (-1 == rv) ? PR_FAILURE : PR_SUCCESS;
} /* pt_FileInfo */

static PRStatus pt_FileInfo64(PRFileDesc* fd, PRFileInfo64* info) {
 PRInt32 rv = _PR_MD_GETOPENFILEINFO64(fd, info);
 return (-1 == rv) ? PR_FAILURE : PR_SUCCESS;
} /* pt_FileInfo64 */

static PRStatus pt_Synch(PRFileDesc* fd) {
 return (NULL == fd) ? PR_FAILURE : PR_SUCCESS;
} /* pt_Synch */

static PRStatus pt_Fsync(PRFileDesc* fd) {
 PRIntn rv = -1;
 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 rv = fsync(fd->secret->md.osfd);
 if (rv < 0) {
   pt_MapError(_PR_MD_MAP_FSYNC_ERROR, errno);
   return PR_FAILURE;
 }
 return PR_SUCCESS;
} /* pt_Fsync */

static PRStatus pt_Connect(PRFileDesc* fd, const PRNetAddr* addr,
                          PRIntervalTime timeout) {
 PRIntn rv = -1, syserrno;
 pt_SockLen addr_len;
 const PRNetAddr* addrp = addr;
#  if defined(_PR_HAVE_SOCKADDR_LEN) || defined(_PR_INET6)
 PRNetAddr addrCopy;
#  endif
#  ifdef _PR_HAVE_SOCKADDR_LEN
 PRUint16 md_af = addr->raw.family;
#  endif

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 PR_ASSERT(IsValidNetAddr(addr) == PR_TRUE);
 addr_len = PR_NETADDR_SIZE(addr);
#  ifdef _PR_INET6
 if (addr->raw.family == PR_AF_INET6) {
#    ifdef _PR_HAVE_SOCKADDR_LEN
   md_af = AF_INET6;
#    else
   addrCopy = *addr;
   addrCopy.raw.family = AF_INET6;
   addrp = &addrCopy;
#    endif
 }
#  endif

#  ifdef _PR_HAVE_SOCKADDR_LEN
 addrCopy = *addr;
 ((struct sockaddr*)&addrCopy)->sa_len = addr_len;
 ((struct sockaddr*)&addrCopy)->sa_family = md_af;
 addrp = &addrCopy;
#  endif
 rv = connect(fd->secret->md.osfd, (struct sockaddr*)addrp, addr_len);
 syserrno = errno;
 if ((-1 == rv) && (EINPROGRESS == syserrno) && (!fd->secret->nonblocking)) {
   if (PR_INTERVAL_NO_WAIT == timeout) {
     syserrno = ETIMEDOUT;
   } else {
     pt_Continuation op;
     op.arg1.osfd = fd->secret->md.osfd;
     op.arg2.buffer = (void*)addrp;
     op.arg3.amount = addr_len;
     op.timeout = timeout;
     op.function = pt_connect_cont;
     op.event = POLLOUT | POLLPRI;
     rv = pt_Continue(&op);
     syserrno = op.syserrno;
   }
 }
 if (-1 == rv) {
   pt_MapError(_PR_MD_MAP_CONNECT_ERROR, syserrno);
   return PR_FAILURE;
 }
 return PR_SUCCESS;
} /* pt_Connect */

static PRStatus pt_ConnectContinue(PRFileDesc* fd, PRInt16 out_flags) {
 int err;
 PRInt32 osfd;

 if (out_flags & PR_POLL_NVAL) {
   PR_SetError(PR_BAD_DESCRIPTOR_ERROR, 0);
   return PR_FAILURE;
 }
 if ((out_flags &
      (PR_POLL_WRITE | PR_POLL_EXCEPT | PR_POLL_ERR | PR_POLL_HUP)) == 0) {
   PR_ASSERT(out_flags == 0);
   PR_SetError(PR_IN_PROGRESS_ERROR, 0);
   return PR_FAILURE;
 }

 osfd = fd->secret->md.osfd;

 err = _MD_unix_get_nonblocking_connect_error(osfd);
 if (err != 0) {
   _PR_MD_MAP_CONNECT_ERROR(err);
   return PR_FAILURE;
 }
 return PR_SUCCESS;
} /* pt_ConnectContinue */

PR_IMPLEMENT(PRStatus) PR_GetConnectStatus(const PRPollDesc* pd) {
 /* Find the NSPR layer and invoke its connectcontinue method */
 PRFileDesc* bottom = PR_GetIdentitiesLayer(pd->fd, PR_NSPR_IO_LAYER);

 if (NULL == bottom) {
   PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
   return PR_FAILURE;
 }
 return pt_ConnectContinue(bottom, pd->out_flags);
} /* PR_GetConnectStatus */

static PRFileDesc* pt_Accept(PRFileDesc* fd, PRNetAddr* addr,
                            PRIntervalTime timeout) {
 PRFileDesc* newfd = NULL;
 PRIntn syserrno, osfd = -1;
 pt_SockLen addr_len = sizeof(PRNetAddr);

 if (pt_TestAbort()) {
   return newfd;
 }

#  ifdef _PR_STRICT_ADDR_LEN
 if (addr) {
   /*
    * Set addr->raw.family just so that we can use the
    * PR_NETADDR_SIZE macro.
    */
   addr->raw.family = fd->secret->af;
   addr_len = PR_NETADDR_SIZE(addr);
 }
#  endif

 osfd = accept(fd->secret->md.osfd, (struct sockaddr*)addr, &addr_len);
 syserrno = errno;

 if (osfd == -1) {
   if (fd->secret->nonblocking) {
     goto failed;
   }

   if (EWOULDBLOCK != syserrno && EAGAIN != syserrno &&
       ECONNABORTED != syserrno) {
     goto failed;
   } else {
     if (PR_INTERVAL_NO_WAIT == timeout) {
       syserrno = ETIMEDOUT;
     } else {
       pt_Continuation op;
       op.arg1.osfd = fd->secret->md.osfd;
       op.arg2.buffer = addr;
       op.arg3.addr_len = &addr_len;
       op.timeout = timeout;
       op.function = pt_accept_cont;
       op.event = POLLIN | POLLPRI;
       osfd = pt_Continue(&op);
       syserrno = op.syserrno;
     }
     if (osfd < 0) {
       goto failed;
     }
   }
 }
#  ifdef _PR_HAVE_SOCKADDR_LEN
 /* ignore the sa_len field of struct sockaddr */
 if (addr) {
   addr->raw.family = ((struct sockaddr*)addr)->sa_family;
 }
#  endif /* _PR_HAVE_SOCKADDR_LEN */
#  ifdef _PR_INET6
 if (addr && (AF_INET6 == addr->raw.family)) {
   addr->raw.family = PR_AF_INET6;
 }
#  endif
 newfd = pt_SetMethods(osfd, PR_DESC_SOCKET_TCP, PR_TRUE, PR_FALSE);
 if (newfd == NULL) {
   close(osfd); /* $$$ whoops! this doesn't work $$$ */
 } else {
   PR_ASSERT(IsValidNetAddr(addr) == PR_TRUE);
   PR_ASSERT(IsValidNetAddrLen(addr, addr_len) == PR_TRUE);
#  ifdef LINUX
   /*
    * On Linux, experiments showed that the accepted sockets
    * inherit the TCP_NODELAY socket option of the listening
    * socket.
    */
   newfd->secret->md.tcp_nodelay = fd->secret->md.tcp_nodelay;
#  endif
 }
 return newfd;

failed:
 pt_MapError(_PR_MD_MAP_ACCEPT_ERROR, syserrno);
 return NULL;
} /* pt_Accept */

static PRStatus pt_Bind(PRFileDesc* fd, const PRNetAddr* addr) {
 PRIntn rv;
 pt_SockLen addr_len;
 const PRNetAddr* addrp = addr;
#  if defined(_PR_HAVE_SOCKADDR_LEN) || defined(_PR_INET6)
 PRNetAddr addrCopy;
#  endif
#  ifdef _PR_HAVE_SOCKADDR_LEN
 PRUint16 md_af = addr->raw.family;
#  endif

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 PR_ASSERT(IsValidNetAddr(addr) == PR_TRUE);
 if (addr->raw.family == AF_UNIX) {
   /* Disallow relative pathnames */
   if (addr->local.path[0] != '/'
#  if defined(LINUX)
       /* Linux has abstract socket address support */
       && addr->local.path[0] != 0
#  endif
   ) {
     PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
     return PR_FAILURE;
   }
 }

#  ifdef _PR_INET6
 if (addr->raw.family == PR_AF_INET6) {
#    ifdef _PR_HAVE_SOCKADDR_LEN
   md_af = AF_INET6;
#    else
   addrCopy = *addr;
   addrCopy.raw.family = AF_INET6;
   addrp = &addrCopy;
#    endif
 }
#  endif

 addr_len = PR_NETADDR_SIZE(addr);
#  ifdef _PR_HAVE_SOCKADDR_LEN
 addrCopy = *addr;
 ((struct sockaddr*)&addrCopy)->sa_len = addr_len;
 ((struct sockaddr*)&addrCopy)->sa_family = md_af;
 addrp = &addrCopy;
#  endif
 rv = bind(fd->secret->md.osfd, (struct sockaddr*)addrp, addr_len);

 if (rv == -1) {
   pt_MapError(_PR_MD_MAP_BIND_ERROR, errno);
   return PR_FAILURE;
 }
 return PR_SUCCESS;
} /* pt_Bind */

static PRStatus pt_Listen(PRFileDesc* fd, PRIntn backlog) {
 PRIntn rv;

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 rv = listen(fd->secret->md.osfd, backlog);
 if (rv == -1) {
   pt_MapError(_PR_MD_MAP_LISTEN_ERROR, errno);
   return PR_FAILURE;
 }
 return PR_SUCCESS;
} /* pt_Listen */

static PRStatus pt_Shutdown(PRFileDesc* fd, PRIntn how) {
 PRIntn rv = -1;
 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 rv = shutdown(fd->secret->md.osfd, how);

 if (rv == -1) {
   pt_MapError(_PR_MD_MAP_SHUTDOWN_ERROR, errno);
   return PR_FAILURE;
 }
 return PR_SUCCESS;
} /* pt_Shutdown */

static PRInt16 pt_Poll(PRFileDesc* fd, PRInt16 in_flags, PRInt16* out_flags) {
 *out_flags = 0;
 return in_flags;
} /* pt_Poll */

static PRInt32 pt_Recv(PRFileDesc* fd, void* buf, PRInt32 amount, PRIntn flags,
                      PRIntervalTime timeout) {
 PRInt32 syserrno, bytes = -1;
 PRIntn osflags;

 if (0 == flags) {
   osflags = 0;
 } else if (PR_MSG_PEEK == flags) {
   osflags = MSG_PEEK;
 } else {
   PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
   return bytes;
 }

 if (pt_TestAbort()) {
   return bytes;
 }

 /* recv() is a much slower call on pre-2.6 Solaris than read(). */
#  if defined(SOLARIS)
 if (0 == osflags) {
   bytes = read(fd->secret->md.osfd, buf, amount);
 } else {
   bytes = recv(fd->secret->md.osfd, buf, amount, osflags);
 }
#  else
 bytes = recv(fd->secret->md.osfd, buf, amount, osflags);
#  endif
 syserrno = errno;

 if ((bytes == -1) && (syserrno == EWOULDBLOCK || syserrno == EAGAIN) &&
     (!fd->secret->nonblocking)) {
   if (PR_INTERVAL_NO_WAIT == timeout) {
     syserrno = ETIMEDOUT;
   } else {
     pt_Continuation op;
     op.arg1.osfd = fd->secret->md.osfd;
     op.arg2.buffer = buf;
     op.arg3.amount = amount;
     op.arg4.flags = osflags;
     op.timeout = timeout;
     op.function = pt_recv_cont;
     op.event = POLLIN | POLLPRI;
     bytes = pt_Continue(&op);
     syserrno = op.syserrno;
   }
 }
 if (bytes < 0) {
   pt_MapError(_PR_MD_MAP_RECV_ERROR, syserrno);
 }
 return bytes;
} /* pt_Recv */

static PRInt32 pt_SocketRead(PRFileDesc* fd, void* buf, PRInt32 amount) {
 return pt_Recv(fd, buf, amount, 0, PR_INTERVAL_NO_TIMEOUT);
} /* pt_SocketRead */

static PRInt32 pt_Send(PRFileDesc* fd, const void* buf, PRInt32 amount,
                      PRIntn flags, PRIntervalTime timeout) {
 PRInt32 syserrno, bytes = -1;
 PRBool fNeedContinue = PR_FALSE;
#  if defined(SOLARIS)
 PRInt32 tmp_amount = amount;
#  endif

 if (pt_TestAbort()) {
   return bytes;
 }

 /*
  * On pre-2.6 Solaris, send() is much slower than write().
  * On 2.6 and beyond, with in-kernel sockets, send() and
  * write() are fairly equivalent in performance.
  */
#  if defined(SOLARIS)
 PR_ASSERT(0 == flags);
retry:
 bytes = write(fd->secret->md.osfd, buf, tmp_amount);
#  else
 bytes = send(fd->secret->md.osfd, buf, amount, flags);
#  endif
 syserrno = errno;

#  if defined(SOLARIS)
 /*
  * The write system call has been reported to return the ERANGE error
  * on occasion. Try to write in smaller chunks to workaround this bug.
  */
 if ((bytes == -1) && (syserrno == ERANGE)) {
   if (tmp_amount > 1) {
     tmp_amount = tmp_amount / 2; /* half the bytes */
     goto retry;
   }
 }
#  endif

 if ((bytes >= 0) && (bytes < amount) && (!fd->secret->nonblocking)) {
   if (PR_INTERVAL_NO_WAIT == timeout) {
     bytes = -1;
     syserrno = ETIMEDOUT;
   } else {
     buf = (char*)buf + bytes;
     amount -= bytes;
     fNeedContinue = PR_TRUE;
   }
 }
 if ((bytes == -1) && (syserrno == EWOULDBLOCK || syserrno == EAGAIN) &&
     (!fd->secret->nonblocking)) {
   if (PR_INTERVAL_NO_WAIT == timeout) {
     syserrno = ETIMEDOUT;
   } else {
     bytes = 0;
     fNeedContinue = PR_TRUE;
   }
 }

 if (fNeedContinue == PR_TRUE) {
   pt_Continuation op;
   op.arg1.osfd = fd->secret->md.osfd;
   op.arg2.buffer = (void*)buf;
   op.arg3.amount = amount;
   op.arg4.flags = flags;
   op.timeout = timeout;
   op.result.code = bytes; /* initialize the number sent */
   op.function = pt_send_cont;
   op.event = POLLOUT | POLLPRI;
   bytes = pt_Continue(&op);
   syserrno = op.syserrno;
 }
 if (bytes == -1) {
   pt_MapError(_PR_MD_MAP_SEND_ERROR, syserrno);
 }
 return bytes;
} /* pt_Send */

static PRInt32 pt_SocketWrite(PRFileDesc* fd, const void* buf, PRInt32 amount) {
 return pt_Send(fd, buf, amount, 0, PR_INTERVAL_NO_TIMEOUT);
} /* pt_SocketWrite */

static PRInt32 pt_SendTo(PRFileDesc* fd, const void* buf, PRInt32 amount,
                        PRIntn flags, const PRNetAddr* addr,
                        PRIntervalTime timeout) {
 PRInt32 syserrno, bytes = -1;
 PRBool fNeedContinue = PR_FALSE;
 pt_SockLen addr_len;
 const PRNetAddr* addrp = addr;
#  if defined(_PR_HAVE_SOCKADDR_LEN) || defined(_PR_INET6)
 PRNetAddr addrCopy;
#  endif
#  ifdef _PR_HAVE_SOCKADDR_LEN
 PRUint16 md_af = addr->raw.family;
#  endif

 if (pt_TestAbort()) {
   return bytes;
 }

 PR_ASSERT(IsValidNetAddr(addr) == PR_TRUE);
#  ifdef _PR_INET6
 if (addr->raw.family == PR_AF_INET6) {
#    ifdef _PR_HAVE_SOCKADDR_LEN
   md_af = AF_INET6;
#    else
   addrCopy = *addr;
   addrCopy.raw.family = AF_INET6;
   addrp = &addrCopy;
#    endif
 }
#  endif

 addr_len = PR_NETADDR_SIZE(addr);
#  ifdef _PR_HAVE_SOCKADDR_LEN
 addrCopy = *addr;
 ((struct sockaddr*)&addrCopy)->sa_len = addr_len;
 ((struct sockaddr*)&addrCopy)->sa_family = md_af;
 addrp = &addrCopy;
#  endif
 bytes = sendto(fd->secret->md.osfd, buf, amount, flags,
                (struct sockaddr*)addrp, addr_len);
 syserrno = errno;
 if ((bytes == -1) && (syserrno == EWOULDBLOCK || syserrno == EAGAIN) &&
     (!fd->secret->nonblocking)) {
   if (PR_INTERVAL_NO_WAIT == timeout) {
     syserrno = ETIMEDOUT;
   } else {
     fNeedContinue = PR_TRUE;
   }
 }
 if (fNeedContinue == PR_TRUE) {
   pt_Continuation op;
   op.arg1.osfd = fd->secret->md.osfd;
   op.arg2.buffer = (void*)buf;
   op.arg3.amount = amount;
   op.arg4.flags = flags;
   op.arg5.addr = (PRNetAddr*)addrp;
   op.timeout = timeout;
   op.result.code = 0; /* initialize the number sent */
   op.function = pt_sendto_cont;
   op.event = POLLOUT | POLLPRI;
   bytes = pt_Continue(&op);
   syserrno = op.syserrno;
 }
 if (bytes < 0) {
   pt_MapError(_PR_MD_MAP_SENDTO_ERROR, syserrno);
 }
 return bytes;
} /* pt_SendTo */

#  if defined(LINUX) || defined(DARWIN)
/* Linux uses SendTo to send data during TCP Fast Open. OSX uses connectx, but
* we will make it imitate the Linux's interface. */
static PRInt32 pt_TCP_SendTo(PRFileDesc* fd, const void* buf, PRInt32 amount,
                            PRIntn flags, const PRNetAddr* addr,
                            PRIntervalTime timeout) {
#    if defined(LINUX) || HAS_CONNECTX
 PRInt32 syserrno;
 PRBool fNeedContinue = PR_FALSE;
 pt_SockLen addr_len;
 const PRNetAddr* addrp = addr;
#      if defined(_PR_HAVE_SOCKADDR_LEN) || defined(_PR_INET6)
 PRNetAddr addrCopy;
#      endif
#      ifdef _PR_HAVE_SOCKADDR_LEN
 PRUint16 md_af = addr->raw.family;
#      endif

 if (pt_TestAbort()) {
   return -1;
 }

 PR_ASSERT(IsValidNetAddr(addr) == PR_TRUE);
 addr_len = PR_NETADDR_SIZE(addr);
#      if defined(_PR_INET6)
 if (addr->raw.family == PR_AF_INET6) {
#        ifdef _PR_HAVE_SOCKADDR_LEN
   md_af = AF_INET6;
#        else
   /* If _PR_INET6 is defined and it is PR_AF_INET6 we set family
    * to AF_INET6. */
   addrCopy = *addr;
   addrCopy.raw.family = AF_INET6;
   addrp = &addrCopy;
#        endif
 }
#      endif

#      ifdef _PR_HAVE_SOCKADDR_LEN
 /* if _PR_HAVE_SOCKADDR_LEN is defined and it is PR_AF_INET6 we set family
  * to AF_INET6 and we set address length. */
 addrCopy = *addr;
 ((struct sockaddr*)&addrCopy)->sa_len = addr_len;
 ((struct sockaddr*)&addrCopy)->sa_family = md_af;
 addrp = &addrCopy;
#      endif

 size_t bytes = 0;
 PRInt32 netResult = 0;
#      ifndef HAS_CONNECTX
 netResult = sendto(fd->secret->md.osfd, buf, amount, MSG_FASTOPEN,
                    (struct sockaddr*)addrp, addr_len);
 if (netResult >= 0) {
   bytes = netResult;
 }
#      else
 sa_endpoints_t endpoints;
 endpoints.sae_srcif = 0;
 endpoints.sae_srcaddr = NULL;
 endpoints.sae_srcaddrlen = 0;
 endpoints.sae_dstaddr = (struct sockaddr*)addrp;
 endpoints.sae_dstaddrlen = addr_len;
 struct iovec iov[1];
 iov[0].iov_base = buf;
 iov[0].iov_len = amount;
 netResult = connectx(fd->secret->md.osfd, &endpoints, SAE_ASSOCID_ANY,
                      CONNECT_DATA_IDEMPOTENT, iov, 1, &bytes, NULL);
#      endif
 syserrno = errno;
 if ((netResult < 0) && (syserrno == EWOULDBLOCK || syserrno == EAGAIN) &&
     (!fd->secret->nonblocking)) {
   if (PR_INTERVAL_NO_WAIT == timeout) {
     syserrno = ETIMEDOUT;
   } else {
     fNeedContinue = PR_TRUE;
   }
 }
 if (fNeedContinue == PR_TRUE) {
   pt_Continuation op;
   op.arg1.osfd = fd->secret->md.osfd;
   op.arg2.buffer = (void*)buf;
   op.arg3.amount = amount;
   op.arg4.flags = flags;
   op.arg5.addr = (PRNetAddr*)addrp;
   op.timeout = timeout;
   op.result.code = 0; /* initialize the number sent */
   op.function = pt_sendto_cont;
   op.event = POLLOUT | POLLPRI;
   netResult = pt_Continue(&op);
   if (netResult >= 0) {
     bytes = netResult;
   }
   syserrno = op.syserrno;
 }
 if (netResult < 0) {
   pt_MapError(_PR_MD_MAP_SENDTO_ERROR, syserrno);
   return -1;
 }
 return bytes;
#    else /* !(defined(LINUX) || HAS_CONNECTX) */
 PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0);
 return -1;
#    endif
} /* pt_TCP_SendTo */
#  endif /* LINUX || DARWIN */

static PRInt32 pt_RecvFrom(PRFileDesc* fd, void* buf, PRInt32 amount,
                          PRIntn flags, PRNetAddr* addr,
                          PRIntervalTime timeout) {
 PRBool fNeedContinue = PR_FALSE;
 PRInt32 syserrno, bytes = -1;
 pt_SockLen addr_len = sizeof(PRNetAddr);

 if (pt_TestAbort()) {
   return bytes;
 }

 bytes = recvfrom(fd->secret->md.osfd, buf, amount, flags,
                  (struct sockaddr*)addr, &addr_len);
 syserrno = errno;

 if ((bytes == -1) && (syserrno == EWOULDBLOCK || syserrno == EAGAIN) &&
     (!fd->secret->nonblocking)) {
   if (PR_INTERVAL_NO_WAIT == timeout) {
     syserrno = ETIMEDOUT;
   } else {
     fNeedContinue = PR_TRUE;
   }
 }

 if (fNeedContinue == PR_TRUE) {
   pt_Continuation op;
   op.arg1.osfd = fd->secret->md.osfd;
   op.arg2.buffer = buf;
   op.arg3.amount = amount;
   op.arg4.flags = flags;
   op.arg5.addr = addr;
   op.timeout = timeout;
   op.function = pt_recvfrom_cont;
   op.event = POLLIN | POLLPRI;
   bytes = pt_Continue(&op);
   syserrno = op.syserrno;
 }
 if (bytes >= 0) {
#  ifdef _PR_HAVE_SOCKADDR_LEN
   /* ignore the sa_len field of struct sockaddr */
   if (addr) {
     addr->raw.family = ((struct sockaddr*)addr)->sa_family;
   }
#  endif /* _PR_HAVE_SOCKADDR_LEN */
#  ifdef _PR_INET6
   if (addr && (AF_INET6 == addr->raw.family)) {
     addr->raw.family = PR_AF_INET6;
   }
#  endif
 } else {
   pt_MapError(_PR_MD_MAP_RECVFROM_ERROR, syserrno);
 }
 return bytes;
} /* pt_RecvFrom */

#  ifdef AIX
#    ifndef HAVE_SEND_FILE
static pthread_once_t pt_aix_sendfile_once_block = PTHREAD_ONCE_INIT;

static void pt_aix_sendfile_init_routine(void) {
 void* handle = dlopen(NULL, RTLD_NOW | RTLD_GLOBAL);
 pt_aix_sendfile_fptr = (ssize_t(*)())dlsym(handle, "send_file");
 dlclose(handle);
}

/*
* pt_AIXDispatchSendFile
*/
static PRInt32 pt_AIXDispatchSendFile(PRFileDesc* sd, PRSendFileData* sfd,
                                     PRTransmitFileFlags flags,
                                     PRIntervalTime timeout) {
 int rv;

 rv = pthread_once(&pt_aix_sendfile_once_block, pt_aix_sendfile_init_routine);
 PR_ASSERT(0 == rv);
 if (pt_aix_sendfile_fptr) {
   return pt_AIXSendFile(sd, sfd, flags, timeout);
 } else {
   return PR_EmulateSendFile(sd, sfd, flags, timeout);
 }
}
#    endif /* !HAVE_SEND_FILE */

/*
* pt_AIXSendFile
*
*    Send file sfd->fd across socket sd. If specified, header and trailer
*    buffers are sent before and after the file, respectively.
*
*    PR_TRANSMITFILE_CLOSE_SOCKET flag - close socket after sending file
*
*    return number of bytes sent or -1 on error
*
*      This implementation takes advantage of the send_file() system
*      call available in AIX 4.3.2.
*/

static PRInt32 pt_AIXSendFile(PRFileDesc* sd, PRSendFileData* sfd,
                             PRTransmitFileFlags flags,
                             PRIntervalTime timeout) {
 struct sf_parms sf_struct;
 uint_t send_flags;
 ssize_t rv;
 int syserrno;
 PRInt32 count;
 unsigned long long saved_file_offset;
 long long saved_file_bytes;

 sf_struct.header_data = (void*)sfd->header; /* cast away the 'const' */
 sf_struct.header_length = sfd->hlen;
 sf_struct.file_descriptor = sfd->fd->secret->md.osfd;
 sf_struct.file_size = 0;
 sf_struct.file_offset = sfd->file_offset;
 if (sfd->file_nbytes == 0) {
   sf_struct.file_bytes = -1;
 } else {
   sf_struct.file_bytes = sfd->file_nbytes;
 }
 sf_struct.trailer_data = (void*)sfd->trailer;
 sf_struct.trailer_length = sfd->tlen;
 sf_struct.bytes_sent = 0;

 saved_file_offset = sf_struct.file_offset;
 saved_file_bytes = sf_struct.file_bytes;

 send_flags = 0; /* flags processed at the end */

 /* The first argument to send_file() is int*. */
 PR_ASSERT(sizeof(int) == sizeof(sd->secret->md.osfd));
 do {
   rv = AIX_SEND_FILE(&sd->secret->md.osfd, &sf_struct, send_flags);
 } while (rv == -1 && (syserrno = errno) == EINTR);

 if (rv == -1) {
   if (syserrno == EAGAIN || syserrno == EWOULDBLOCK) {
     count = 0; /* Not a real error.  Need to continue. */
   } else {
     count = -1;
   }
 } else {
   count = sf_struct.bytes_sent;
   /*
    * A bug in AIX 4.3.2 prevents the 'file_bytes' field from
    * being updated. So, 'file_bytes' is maintained by NSPR to
    * avoid conflict when this bug is fixed in AIX, in the future.
    */
   if (saved_file_bytes != -1) {
     saved_file_bytes -= (sf_struct.file_offset - saved_file_offset);
   }
   sf_struct.file_bytes = saved_file_bytes;
 }

 if ((rv == 1) || ((rv == -1) && (count == 0))) {
   pt_Continuation op;

   op.arg1.osfd = sd->secret->md.osfd;
   op.arg2.buffer = &sf_struct;
   op.arg4.flags = send_flags;
   op.result.code = count;
   op.timeout = timeout;
   op.function = pt_aix_sendfile_cont;
   op.event = POLLOUT | POLLPRI;
   count = pt_Continue(&op);
   syserrno = op.syserrno;
 }

 if (count == -1) {
   pt_MapError(_MD_aix_map_sendfile_error, syserrno);
   return -1;
 }
 if (flags & PR_TRANSMITFILE_CLOSE_SOCKET) {
   PR_Close(sd);
 }
 PR_ASSERT(count ==
           (sfd->hlen + sfd->tlen +
            ((sfd->file_nbytes == 0) ? sf_struct.file_size - sfd->file_offset
                                     : sfd->file_nbytes)));
 return count;
}
#  endif /* AIX */

#  ifdef HPUX11
/*
* pt_HPUXSendFile
*
*    Send file sfd->fd across socket sd. If specified, header and trailer
*    buffers are sent before and after the file, respectively.
*
*    PR_TRANSMITFILE_CLOSE_SOCKET flag - close socket after sending file
*
*    return number of bytes sent or -1 on error
*
*      This implementation takes advantage of the sendfile() system
*      call available in HP-UX B.11.00.
*/

static PRInt32 pt_HPUXSendFile(PRFileDesc* sd, PRSendFileData* sfd,
                              PRTransmitFileFlags flags,
                              PRIntervalTime timeout) {
 struct stat statbuf;
 size_t nbytes_to_send, file_nbytes_to_send;
 struct iovec hdtrl[2]; /* optional header and trailer buffers */
 int send_flags;
 PRInt32 count;
 int syserrno;

 if (sfd->file_nbytes == 0) {
   /* Get file size */
   if (fstat(sfd->fd->secret->md.osfd, &statbuf) == -1) {
     _PR_MD_MAP_FSTAT_ERROR(errno);
     return -1;
   }
   file_nbytes_to_send = statbuf.st_size - sfd->file_offset;
 } else {
   file_nbytes_to_send = sfd->file_nbytes;
 }
 nbytes_to_send = sfd->hlen + sfd->tlen + file_nbytes_to_send;

 hdtrl[0].iov_base = (void*)sfd->header; /* cast away the 'const' */
 hdtrl[0].iov_len = sfd->hlen;
 hdtrl[1].iov_base = (void*)sfd->trailer;
 hdtrl[1].iov_len = sfd->tlen;
 /*
  * SF_DISCONNECT seems to close the socket even if sendfile()
  * only does a partial send on a nonblocking socket.  This
  * would prevent the subsequent sendfile() calls on that socket
  * from working.  So we don't use the SD_DISCONNECT flag.
  */
 send_flags = 0;

 do {
   count = sendfile(sd->secret->md.osfd, sfd->fd->secret->md.osfd,
                    sfd->file_offset, file_nbytes_to_send, hdtrl, send_flags);
 } while (count == -1 && (syserrno = errno) == EINTR);

 if (count == -1 && (syserrno == EAGAIN || syserrno == EWOULDBLOCK)) {
   count = 0;
 }
 if (count != -1 && count < nbytes_to_send) {
   pt_Continuation op;

   if (count < sfd->hlen) {
     /* header not sent */

     hdtrl[0].iov_base = ((char*)sfd->header) + count;
     hdtrl[0].iov_len = sfd->hlen - count;
     op.arg3.file_spec.offset = sfd->file_offset;
     op.arg3.file_spec.nbytes = file_nbytes_to_send;
   } else if (count < (sfd->hlen + file_nbytes_to_send)) {
     /* header sent, file not sent */

     hdtrl[0].iov_base = NULL;
     hdtrl[0].iov_len = 0;

     op.arg3.file_spec.offset = sfd->file_offset + count - sfd->hlen;
     op.arg3.file_spec.nbytes = file_nbytes_to_send - (count - sfd->hlen);
   } else if (count < (sfd->hlen + file_nbytes_to_send + sfd->tlen)) {
     PRUint32 trailer_nbytes_sent;

     /* header sent, file sent, trailer not sent */

     hdtrl[0].iov_base = NULL;
     hdtrl[0].iov_len = 0;
     /*
      * set file offset and len so that no more file data is
      * sent
      */
     op.arg3.file_spec.offset = statbuf.st_size;
     op.arg3.file_spec.nbytes = 0;

     trailer_nbytes_sent = count - sfd->hlen - file_nbytes_to_send;
     hdtrl[1].iov_base = ((char*)sfd->trailer) + trailer_nbytes_sent;
     hdtrl[1].iov_len = sfd->tlen - trailer_nbytes_sent;
   }

   op.arg1.osfd = sd->secret->md.osfd;
   op.filedesc = sfd->fd->secret->md.osfd;
   op.arg2.buffer = hdtrl;
   op.arg3.file_spec.st_size = statbuf.st_size;
   op.arg4.flags = send_flags;
   op.nbytes_to_send = nbytes_to_send - count;
   op.result.code = count;
   op.timeout = timeout;
   op.function = pt_hpux_sendfile_cont;
   op.event = POLLOUT | POLLPRI;
   count = pt_Continue(&op);
   syserrno = op.syserrno;
 }

 if (count == -1) {
   pt_MapError(_MD_hpux_map_sendfile_error, syserrno);
   return -1;
 }
 if (flags & PR_TRANSMITFILE_CLOSE_SOCKET) {
   PR_Close(sd);
 }
 PR_ASSERT(count == nbytes_to_send);
 return count;
}

#  endif /* HPUX11 */

#  ifdef SOLARIS

/*
*    pt_SolarisSendFile
*
*    Send file sfd->fd across socket sd. If specified, header and trailer
*    buffers are sent before and after the file, respectively.
*
*    PR_TRANSMITFILE_CLOSE_SOCKET flag - close socket after sending file
*
*    return number of bytes sent or -1 on error
*
*    This implementation takes advantage of the sendfilev() system
*    call available in Solaris 8.
*/

static PRInt32 pt_SolarisSendFile(PRFileDesc* sd, PRSendFileData* sfd,
                                 PRTransmitFileFlags flags,
                                 PRIntervalTime timeout) {
 struct stat statbuf;
 size_t nbytes_to_send, file_nbytes_to_send;
 struct sendfilevec sfv_struct[3];
 int sfvcnt = 0;
 size_t xferred;
 PRInt32 count;
 int syserrno;

 if (sfd->file_nbytes == 0) {
   /* Get file size */
   if (fstat(sfd->fd->secret->md.osfd, &statbuf) == -1) {
     _PR_MD_MAP_FSTAT_ERROR(errno);
     return -1;
   }
   file_nbytes_to_send = statbuf.st_size - sfd->file_offset;
 } else {
   file_nbytes_to_send = sfd->file_nbytes;
 }

 nbytes_to_send = sfd->hlen + sfd->tlen + file_nbytes_to_send;

 if (sfd->hlen != 0) {
   sfv_struct[sfvcnt].sfv_fd = SFV_FD_SELF;
   sfv_struct[sfvcnt].sfv_flag = 0;
   sfv_struct[sfvcnt].sfv_off = (off_t)sfd->header;
   sfv_struct[sfvcnt].sfv_len = sfd->hlen;
   sfvcnt++;
 }

 if (file_nbytes_to_send != 0) {
   sfv_struct[sfvcnt].sfv_fd = sfd->fd->secret->md.osfd;
   sfv_struct[sfvcnt].sfv_flag = 0;
   sfv_struct[sfvcnt].sfv_off = sfd->file_offset;
   sfv_struct[sfvcnt].sfv_len = file_nbytes_to_send;
   sfvcnt++;
 }

 if (sfd->tlen != 0) {
   sfv_struct[sfvcnt].sfv_fd = SFV_FD_SELF;
   sfv_struct[sfvcnt].sfv_flag = 0;
   sfv_struct[sfvcnt].sfv_off = (off_t)sfd->trailer;
   sfv_struct[sfvcnt].sfv_len = sfd->tlen;
   sfvcnt++;
 }

 if (0 == sfvcnt) {
   count = 0;
   goto done;
 }

 /*
  * Strictly speaking, we may have sent some bytes when the
  * sendfilev() is interrupted and we should retry it from an
  * updated offset.  We are not doing that here.
  */
 count = SOLARIS_SENDFILEV(sd->secret->md.osfd, sfv_struct, sfvcnt, &xferred);

 PR_ASSERT((count == -1) || (count == xferred));

 if (count == -1) {
   syserrno = errno;
   if (syserrno == EINTR || syserrno == EAGAIN || syserrno == EWOULDBLOCK) {
     count = xferred;
   }
 } else if (count == 0) {
   /*
    * We are now at EOF. The file was truncated. Solaris sendfile is
    * supposed to return 0 and no error in this case, though some versions
    * may return -1 and EINVAL .
    */
   count = -1;
   syserrno = 0; /* will be treated as EOF */
 }

 if (count != -1 && count < nbytes_to_send) {
   pt_Continuation op;
   struct sendfilevec* vec = sfv_struct;
   PRInt32 rem = count;

   while (rem >= vec->sfv_len) {
     rem -= vec->sfv_len;
     vec++;
     sfvcnt--;
   }
   PR_ASSERT(sfvcnt > 0);

   vec->sfv_off += rem;
   vec->sfv_len -= rem;
   PR_ASSERT(vec->sfv_len > 0);

   op.arg1.osfd = sd->secret->md.osfd;
   op.arg2.buffer = vec;
   op.arg3.amount = sfvcnt;
   op.arg4.flags = 0;
   op.nbytes_to_send = nbytes_to_send - count;
   op.result.code = count;
   op.timeout = timeout;
   op.function = pt_solaris_sendfile_cont;
   op.event = POLLOUT | POLLPRI;
   count = pt_Continue(&op);
   syserrno = op.syserrno;
 }

done:
 if (count == -1) {
   pt_MapError(_MD_solaris_map_sendfile_error, syserrno);
   return -1;
 }
 if (flags & PR_TRANSMITFILE_CLOSE_SOCKET) {
   PR_Close(sd);
 }
 PR_ASSERT(count == nbytes_to_send);
 return count;
}

#    ifndef HAVE_SENDFILEV
static pthread_once_t pt_solaris_sendfilev_once_block = PTHREAD_ONCE_INIT;

static void pt_solaris_sendfilev_init_routine(void) {
 void* handle;
 PRBool close_it = PR_FALSE;

 /*
  * We do not want to unload libsendfile.so.  This handle is leaked
  * intentionally.
  */
 handle = dlopen("libsendfile.so", RTLD_LAZY | RTLD_GLOBAL);
 PR_LOG(_pr_io_lm, PR_LOG_DEBUG,
        ("dlopen(libsendfile.so) returns %p", handle));

 if (NULL == handle) {
   /*
    * The dlopen(0, mode) call is to allow for the possibility that
    * sendfilev() may become part of a standard system library in a
    * future Solaris release.
    */
   handle = dlopen(0, RTLD_LAZY | RTLD_GLOBAL);
   PR_LOG(_pr_io_lm, PR_LOG_DEBUG, ("dlopen(0) returns %p", handle));
   close_it = PR_TRUE;
 }
 pt_solaris_sendfilev_fptr = (ssize_t(*)())dlsym(handle, "sendfilev");
 PR_LOG(_pr_io_lm, PR_LOG_DEBUG,
        ("dlsym(sendfilev) returns %p", pt_solaris_sendfilev_fptr));

 if (close_it) {
   dlclose(handle);
 }
}

/*
* pt_SolarisDispatchSendFile
*/
static PRInt32 pt_SolarisDispatchSendFile(PRFileDesc* sd, PRSendFileData* sfd,
                                         PRTransmitFileFlags flags,
                                         PRIntervalTime timeout) {
 int rv;

 rv = pthread_once(&pt_solaris_sendfilev_once_block,
                   pt_solaris_sendfilev_init_routine);
 PR_ASSERT(0 == rv);
 if (pt_solaris_sendfilev_fptr) {
   return pt_SolarisSendFile(sd, sfd, flags, timeout);
 } else {
   return PR_EmulateSendFile(sd, sfd, flags, timeout);
 }
}
#    endif /* !HAVE_SENDFILEV */

#  endif /* SOLARIS */

#  ifdef LINUX
/*
* pt_LinuxSendFile
*
*    Send file sfd->fd across socket sd. If specified, header and trailer
*    buffers are sent before and after the file, respectively.
*
*    PR_TRANSMITFILE_CLOSE_SOCKET flag - close socket after sending file
*
*    return number of bytes sent or -1 on error
*
*      This implementation takes advantage of the sendfile() system
*      call available in Linux kernel 2.2 or higher.
*/

static PRInt32 pt_LinuxSendFile(PRFileDesc* sd, PRSendFileData* sfd,
                               PRTransmitFileFlags flags,
                               PRIntervalTime timeout) {
 struct stat statbuf;
 size_t file_nbytes_to_send;
 PRInt32 count = 0;
 ssize_t rv;
 int syserrno;
 off_t offset;
 PRBool tcp_cork_enabled = PR_FALSE;
 int tcp_cork;

 if (sfd->file_nbytes == 0) {
   /* Get file size */
   if (fstat(sfd->fd->secret->md.osfd, &statbuf) == -1) {
     _PR_MD_MAP_FSTAT_ERROR(errno);
     return -1;
   }
   file_nbytes_to_send = statbuf.st_size - sfd->file_offset;
 } else {
   file_nbytes_to_send = sfd->file_nbytes;
 }

 if ((sfd->hlen != 0 || sfd->tlen != 0) && sd->secret->md.tcp_nodelay == 0) {
   tcp_cork = 1;
   if (setsockopt(sd->secret->md.osfd, SOL_TCP, TCP_CORK, &tcp_cork,
                  sizeof tcp_cork) == 0) {
     tcp_cork_enabled = PR_TRUE;
   } else {
     syserrno = errno;
     if (syserrno != EINVAL) {
       _PR_MD_MAP_SETSOCKOPT_ERROR(syserrno);
       return -1;
     }
     /*
      * The most likely reason for the EINVAL error is that
      * TCP_NODELAY is set (with a function other than
      * PR_SetSocketOption).  This is not fatal, so we keep
      * on going.
      */
     PR_LOG(_pr_io_lm, PR_LOG_WARNING,
            ("pt_LinuxSendFile: "
             "setsockopt(TCP_CORK) failed with EINVAL\n"));
   }
 }

 if (sfd->hlen != 0) {
   count = PR_Send(sd, sfd->header, sfd->hlen, 0, timeout);
   if (count == -1) {
     goto failed;
   }
 }

 if (file_nbytes_to_send != 0) {
   offset = sfd->file_offset;
   do {
     rv = sendfile(sd->secret->md.osfd, sfd->fd->secret->md.osfd, &offset,
                   file_nbytes_to_send);
   } while (rv == -1 && (syserrno = errno) == EINTR);
   if (rv == -1) {
     if (syserrno != EAGAIN && syserrno != EWOULDBLOCK) {
       _MD_linux_map_sendfile_error(syserrno);
       count = -1;
       goto failed;
     }
     rv = 0;
   }
   PR_ASSERT(rv == offset - sfd->file_offset);
   count += rv;

   if (rv < file_nbytes_to_send) {
     pt_Continuation op;

     op.arg1.osfd = sd->secret->md.osfd;
     op.in_fd = sfd->fd->secret->md.osfd;
     op.offset = offset;
     op.count = file_nbytes_to_send - rv;
     op.result.code = count;
     op.timeout = timeout;
     op.function = pt_linux_sendfile_cont;
     op.event = POLLOUT | POLLPRI;
     count = pt_Continue(&op);
     syserrno = op.syserrno;
     if (count == -1) {
       pt_MapError(_MD_linux_map_sendfile_error, syserrno);
       goto failed;
     }
   }
 }

 if (sfd->tlen != 0) {
   rv = PR_Send(sd, sfd->trailer, sfd->tlen, 0, timeout);
   if (rv == -1) {
     count = -1;
     goto failed;
   }
   count += rv;
 }

failed:
 if (tcp_cork_enabled) {
   tcp_cork = 0;
   if (setsockopt(sd->secret->md.osfd, SOL_TCP, TCP_CORK, &tcp_cork,
                  sizeof tcp_cork) == -1 &&
       count != -1) {
     _PR_MD_MAP_SETSOCKOPT_ERROR(errno);
     count = -1;
   }
 }
 if (count != -1) {
   if (flags & PR_TRANSMITFILE_CLOSE_SOCKET) {
     PR_Close(sd);
   }
   PR_ASSERT(count == sfd->hlen + sfd->tlen + file_nbytes_to_send);
 }
 return count;
}
#  endif /* LINUX */

#  ifdef AIX
extern int _pr_aix_send_file_use_disabled;
#  endif

static PRInt32 pt_SendFile(PRFileDesc* sd, PRSendFileData* sfd,
                          PRTransmitFileFlags flags, PRIntervalTime timeout) {
 if (pt_TestAbort()) {
   return -1;
 }
 /* The socket must be in blocking mode. */
 if (sd->secret->nonblocking) {
   PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
   return -1;
 }
#  ifdef HPUX11
 return (pt_HPUXSendFile(sd, sfd, flags, timeout));
#  elif defined(AIX)
#    ifdef HAVE_SEND_FILE
 /*
  * A bug in AIX 4.3.2 results in corruption of data transferred by
  * send_file(); AIX patch PTF U463956 contains the fix.  A user can
  * disable the use of send_file function in NSPR, when this patch is
  * not installed on the system, by setting the envionment variable
  * NSPR_AIX_SEND_FILE_USE_DISABLED to 1.
  */
 if (_pr_aix_send_file_use_disabled) {
   return (PR_EmulateSendFile(sd, sfd, flags, timeout));
 } else {
   return (pt_AIXSendFile(sd, sfd, flags, timeout));
 }
#    else
 return (PR_EmulateSendFile(sd, sfd, flags, timeout));
 /* return(pt_AIXDispatchSendFile(sd, sfd, flags, timeout));*/
#    endif /* HAVE_SEND_FILE */
#  elif defined(SOLARIS)
#    ifdef HAVE_SENDFILEV
 return (pt_SolarisSendFile(sd, sfd, flags, timeout));
#    else
 return (pt_SolarisDispatchSendFile(sd, sfd, flags, timeout));
#    endif /* HAVE_SENDFILEV */
#  elif defined(LINUX)
 return (pt_LinuxSendFile(sd, sfd, flags, timeout));
#  else
 return (PR_EmulateSendFile(sd, sfd, flags, timeout));
#  endif
}

static PRInt32 pt_TransmitFile(PRFileDesc* sd, PRFileDesc* fd,
                              const void* headers, PRInt32 hlen,
                              PRTransmitFileFlags flags,
                              PRIntervalTime timeout) {
 PRSendFileData sfd;

 sfd.fd = fd;
 sfd.file_offset = 0;
 sfd.file_nbytes = 0;
 sfd.header = headers;
 sfd.hlen = hlen;
 sfd.trailer = NULL;
 sfd.tlen = 0;

 return (pt_SendFile(sd, &sfd, flags, timeout));
} /* pt_TransmitFile */

static PRInt32 pt_AcceptRead(PRFileDesc* sd, PRFileDesc** nd, PRNetAddr** raddr,
                            void* buf, PRInt32 amount,
                            PRIntervalTime timeout) {
 PRInt32 rv = -1;

 if (pt_TestAbort()) {
   return rv;
 }
 /* The socket must be in blocking mode. */
 if (sd->secret->nonblocking) {
   PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
   return rv;
 }

 rv = PR_EmulateAcceptRead(sd, nd, raddr, buf, amount, timeout);
 return rv;
} /* pt_AcceptRead */

static PRStatus pt_GetSockName(PRFileDesc* fd, PRNetAddr* addr) {
 PRIntn rv = -1;
 pt_SockLen addr_len = sizeof(PRNetAddr);

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 rv = getsockname(fd->secret->md.osfd, (struct sockaddr*)addr, &addr_len);
 if (rv == -1) {
   pt_MapError(_PR_MD_MAP_GETSOCKNAME_ERROR, errno);
   return PR_FAILURE;
 }
#  ifdef _PR_HAVE_SOCKADDR_LEN
 /* ignore the sa_len field of struct sockaddr */
 if (addr) {
   addr->raw.family = ((struct sockaddr*)addr)->sa_family;
 }
#  endif /* _PR_HAVE_SOCKADDR_LEN */
#  ifdef _PR_INET6
 if (AF_INET6 == addr->raw.family) {
   addr->raw.family = PR_AF_INET6;
 }
#  endif
 PR_ASSERT(IsValidNetAddr(addr) == PR_TRUE);
 PR_ASSERT(IsValidNetAddrLen(addr, addr_len) == PR_TRUE);
 return PR_SUCCESS;
} /* pt_GetSockName */

static PRStatus pt_GetPeerName(PRFileDesc* fd, PRNetAddr* addr) {
 PRIntn rv = -1;
 pt_SockLen addr_len = sizeof(PRNetAddr);

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 rv = getpeername(fd->secret->md.osfd, (struct sockaddr*)addr, &addr_len);

 if (rv == -1) {
   pt_MapError(_PR_MD_MAP_GETPEERNAME_ERROR, errno);
   return PR_FAILURE;
 }
#  ifdef _PR_HAVE_SOCKADDR_LEN
 /* ignore the sa_len field of struct sockaddr */
 if (addr) {
   addr->raw.family = ((struct sockaddr*)addr)->sa_family;
 }
#  endif /* _PR_HAVE_SOCKADDR_LEN */
#  ifdef _PR_INET6
 if (AF_INET6 == addr->raw.family) {
   addr->raw.family = PR_AF_INET6;
 }
#  endif
 PR_ASSERT(IsValidNetAddr(addr) == PR_TRUE);
 PR_ASSERT(IsValidNetAddrLen(addr, addr_len) == PR_TRUE);
 return PR_SUCCESS;
} /* pt_GetPeerName */

static PRStatus pt_GetSocketOption(PRFileDesc* fd, PRSocketOptionData* data) {
 PRIntn rv;
 pt_SockLen length;
 PRInt32 level, name;

 /*
  * PR_SockOpt_Nonblocking is a special case that does not
  * translate to a getsockopt() call
  */
 if (PR_SockOpt_Nonblocking == data->option) {
   data->value.non_blocking = fd->secret->nonblocking;
   return PR_SUCCESS;
 }

 rv = _PR_MapOptionName(data->option, &level, &name);
 if (PR_SUCCESS == rv) {
   switch (data->option) {
     case PR_SockOpt_Linger: {
       struct linger linger;
       length = sizeof(linger);
       rv = getsockopt(fd->secret->md.osfd, level, name, (char*)&linger,
                       &length);
       PR_ASSERT((-1 == rv) || (sizeof(linger) == length));
       data->value.linger.polarity = (linger.l_onoff) ? PR_TRUE : PR_FALSE;
       data->value.linger.linger = PR_SecondsToInterval(linger.l_linger);
       break;
     }
     case PR_SockOpt_Reuseaddr:
     case PR_SockOpt_Keepalive:
     case PR_SockOpt_NoDelay:
     case PR_SockOpt_Broadcast:
     case PR_SockOpt_Reuseport: {
       PRIntn value;
       length = sizeof(PRIntn);
       rv = getsockopt(fd->secret->md.osfd, level, name, (char*)&value,
                       &length);
       PR_ASSERT((-1 == rv) || (sizeof(PRIntn) == length));
       data->value.reuse_addr = (0 == value) ? PR_FALSE : PR_TRUE;
       break;
     }
     case PR_SockOpt_McastLoopback: {
       PRUint8 xbool;
       length = sizeof(xbool);
       rv = getsockopt(fd->secret->md.osfd, level, name, (char*)&xbool,
                       &length);
       PR_ASSERT((-1 == rv) || (sizeof(xbool) == length));
       data->value.mcast_loopback = (0 == xbool) ? PR_FALSE : PR_TRUE;
       break;
     }
     case PR_SockOpt_RecvBufferSize:
     case PR_SockOpt_SendBufferSize:
     case PR_SockOpt_MaxSegment: {
       PRIntn value;
       length = sizeof(PRIntn);
       rv = getsockopt(fd->secret->md.osfd, level, name, (char*)&value,
                       &length);
       PR_ASSERT((-1 == rv) || (sizeof(PRIntn) == length));
       data->value.recv_buffer_size = value;
       break;
     }
     case PR_SockOpt_IpTimeToLive:
     case PR_SockOpt_IpTypeOfService: {
       length = sizeof(PRUintn);
       rv = getsockopt(fd->secret->md.osfd, level, name,
                       (char*)&data->value.ip_ttl, &length);
       PR_ASSERT((-1 == rv) || (sizeof(PRIntn) == length));
       break;
     }
     case PR_SockOpt_McastTimeToLive: {
       PRUint8 ttl;
       length = sizeof(ttl);
       rv = getsockopt(fd->secret->md.osfd, level, name, (char*)&ttl, &length);
       PR_ASSERT((-1 == rv) || (sizeof(ttl) == length));
       data->value.mcast_ttl = ttl;
       break;
     }
     case PR_SockOpt_AddMember:
     case PR_SockOpt_DropMember: {
       struct ip_mreq mreq;
       length = sizeof(mreq);
       rv =
           getsockopt(fd->secret->md.osfd, level, name, (char*)&mreq, &length);
       PR_ASSERT((-1 == rv) || (sizeof(mreq) == length));
       data->value.add_member.mcaddr.inet.ip = mreq.imr_multiaddr.s_addr;
       data->value.add_member.ifaddr.inet.ip = mreq.imr_interface.s_addr;
       break;
     }
     case PR_SockOpt_McastInterface: {
       length = sizeof(data->value.mcast_if.inet.ip);
       rv = getsockopt(fd->secret->md.osfd, level, name,
                       (char*)&data->value.mcast_if.inet.ip, &length);
       PR_ASSERT((-1 == rv) ||
                 (sizeof(data->value.mcast_if.inet.ip) == length));
       break;
     }
     case PR_SockOpt_DontFrag: {
#  if !defined(DARWIN) && !defined(LINUX) && !defined(ANDROID)
       PR_SetError(PR_OPERATION_NOT_SUPPORTED_ERROR, 0);
       rv = PR_FAILURE;
#  else
       PRIntn value;
       length = sizeof(value);
       rv = getsockopt(fd->secret->md.osfd, level, name, (char*)&value,
                       &length);
#    if defined(DARWIN)
       data->value.dont_fragment = value;
#    else
       data->value.dont_fragment = (value == IP_PMTUDISC_DO) ? 1 : 0;
#    endif
#  endif /* !(!defined(DARWIN) && !defined(LINUX) && !defined(ANDROID)) */
       break;
     }
     default:
       PR_NOT_REACHED("Unknown socket option");
       break;
   }
   if (-1 == rv) {
     _PR_MD_MAP_GETSOCKOPT_ERROR(errno);
   }
 }
 return (-1 == rv) ? PR_FAILURE : PR_SUCCESS;
} /* pt_GetSocketOption */

static PRStatus pt_SetSocketOption(PRFileDesc* fd,
                                  const PRSocketOptionData* data) {
 PRIntn rv;
 PRInt32 level, name;

 /*
  * PR_SockOpt_Nonblocking is a special case that does not
  * translate to a setsockopt call.
  */
 if (PR_SockOpt_Nonblocking == data->option) {
   fd->secret->nonblocking = data->value.non_blocking;
   return PR_SUCCESS;
 }

 rv = _PR_MapOptionName(data->option, &level, &name);
 if (PR_SUCCESS == rv) {
   switch (data->option) {
     case PR_SockOpt_Linger: {
       struct linger linger;
       linger.l_onoff = data->value.linger.polarity;
       linger.l_linger = PR_IntervalToSeconds(data->value.linger.linger);
       rv = setsockopt(fd->secret->md.osfd, level, name, (char*)&linger,
                       sizeof(linger));
       break;
     }
     case PR_SockOpt_Reuseaddr:
     case PR_SockOpt_Keepalive:
     case PR_SockOpt_NoDelay:
     case PR_SockOpt_Broadcast:
     case PR_SockOpt_Reuseport: {
       PRIntn value = (data->value.reuse_addr) ? 1 : 0;
       rv = setsockopt(fd->secret->md.osfd, level, name, (char*)&value,
                       sizeof(PRIntn));
#  ifdef LINUX
       /* for pt_LinuxSendFile */
       if (name == TCP_NODELAY && rv == 0) {
         fd->secret->md.tcp_nodelay = value;
       }
#  endif
       break;
     }
     case PR_SockOpt_McastLoopback: {
       PRUint8 xbool = data->value.mcast_loopback ? 1 : 0;
       rv = setsockopt(fd->secret->md.osfd, level, name, (char*)&xbool,
                       sizeof(xbool));
       break;
     }
     case PR_SockOpt_RecvBufferSize:
     case PR_SockOpt_SendBufferSize:
     case PR_SockOpt_MaxSegment: {
       PRIntn value = data->value.recv_buffer_size;
       rv = setsockopt(fd->secret->md.osfd, level, name, (char*)&value,
                       sizeof(PRIntn));
       break;
     }
     case PR_SockOpt_IpTimeToLive:
     case PR_SockOpt_IpTypeOfService: {
       rv = setsockopt(fd->secret->md.osfd, level, name,
                       (char*)&data->value.ip_ttl, sizeof(PRUintn));
       break;
     }
     case PR_SockOpt_McastTimeToLive: {
       PRUint8 ttl = data->value.mcast_ttl;
       rv = setsockopt(fd->secret->md.osfd, level, name, (char*)&ttl,
                       sizeof(ttl));
       break;
     }
     case PR_SockOpt_AddMember:
     case PR_SockOpt_DropMember: {
       struct ip_mreq mreq;
       mreq.imr_multiaddr.s_addr = data->value.add_member.mcaddr.inet.ip;
       mreq.imr_interface.s_addr = data->value.add_member.ifaddr.inet.ip;
       rv = setsockopt(fd->secret->md.osfd, level, name, (char*)&mreq,
                       sizeof(mreq));
       break;
     }
     case PR_SockOpt_McastInterface: {
       rv = setsockopt(fd->secret->md.osfd, level, name,
                       (char*)&data->value.mcast_if.inet.ip,
                       sizeof(data->value.mcast_if.inet.ip));
       break;
     }
     case PR_SockOpt_DontFrag: {
#  if !defined(DARWIN) && !defined(LINUX) && !defined(ANDROID)
       PR_SetError(PR_OPERATION_NOT_SUPPORTED_ERROR, 0);
       rv = PR_FAILURE;
#  else
       PRIntn value;
#    if defined(LINUX) || defined(ANDROID)
       value = (data->value.dont_fragment) ? IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
#    elif defined(DARWIN)
       value = data->value.dont_fragment;
#    endif
       rv = setsockopt(fd->secret->md.osfd, level, name, (char*)&value,
                       sizeof(value));
#  endif /* !defined(DARWIN) && !defined(LINUX) && !defined(ANDROID)) */
       break;
     }
     default:
       PR_NOT_REACHED("Unknown socket option");
       break;
   }
   if (-1 == rv) {
     _PR_MD_MAP_SETSOCKOPT_ERROR(errno);
   }
 }
 return (-1 == rv) ? PR_FAILURE : PR_SUCCESS;
} /* pt_SetSocketOption */

/*****************************************************************************/
/****************************** I/O method objects ***************************/
/*****************************************************************************/

static PRIOMethods _pr_file_methods = {PR_DESC_FILE,
                                      pt_Close,
                                      pt_Read,
                                      pt_Write,
                                      pt_Available_f,
                                      pt_Available64_f,
                                      pt_Fsync,
                                      pt_Seek,
                                      pt_Seek64,
                                      pt_FileInfo,
                                      pt_FileInfo64,
                                      (PRWritevFN)_PR_InvalidInt,
                                      (PRConnectFN)_PR_InvalidStatus,
                                      (PRAcceptFN)_PR_InvalidDesc,
                                      (PRBindFN)_PR_InvalidStatus,
                                      (PRListenFN)_PR_InvalidStatus,
                                      (PRShutdownFN)_PR_InvalidStatus,
                                      (PRRecvFN)_PR_InvalidInt,
                                      (PRSendFN)_PR_InvalidInt,
                                      (PRRecvfromFN)_PR_InvalidInt,
                                      (PRSendtoFN)_PR_InvalidInt,
                                      pt_Poll,
                                      (PRAcceptreadFN)_PR_InvalidInt,
                                      (PRTransmitfileFN)_PR_InvalidInt,
                                      (PRGetsocknameFN)_PR_InvalidStatus,
                                      (PRGetpeernameFN)_PR_InvalidStatus,
                                      (PRReservedFN)_PR_InvalidInt,
                                      (PRReservedFN)_PR_InvalidInt,
                                      (PRGetsocketoptionFN)_PR_InvalidStatus,
                                      (PRSetsocketoptionFN)_PR_InvalidStatus,
                                      (PRSendfileFN)_PR_InvalidInt,
                                      (PRConnectcontinueFN)_PR_InvalidStatus,
                                      (PRReservedFN)_PR_InvalidInt,
                                      (PRReservedFN)_PR_InvalidInt,
                                      (PRReservedFN)_PR_InvalidInt,
                                      (PRReservedFN)_PR_InvalidInt};

static PRIOMethods _pr_pipe_methods = {PR_DESC_PIPE,
                                      pt_Close,
                                      pt_Read,
                                      pt_Write,
                                      pt_Available_s,
                                      pt_Available64_s,
                                      pt_Synch,
                                      (PRSeekFN)_PR_InvalidInt,
                                      (PRSeek64FN)_PR_InvalidInt64,
                                      (PRFileInfoFN)_PR_InvalidStatus,
                                      (PRFileInfo64FN)_PR_InvalidStatus,
                                      (PRWritevFN)_PR_InvalidInt,
                                      (PRConnectFN)_PR_InvalidStatus,
                                      (PRAcceptFN)_PR_InvalidDesc,
                                      (PRBindFN)_PR_InvalidStatus,
                                      (PRListenFN)_PR_InvalidStatus,
                                      (PRShutdownFN)_PR_InvalidStatus,
                                      (PRRecvFN)_PR_InvalidInt,
                                      (PRSendFN)_PR_InvalidInt,
                                      (PRRecvfromFN)_PR_InvalidInt,
                                      (PRSendtoFN)_PR_InvalidInt,
                                      pt_Poll,
                                      (PRAcceptreadFN)_PR_InvalidInt,
                                      (PRTransmitfileFN)_PR_InvalidInt,
                                      (PRGetsocknameFN)_PR_InvalidStatus,
                                      (PRGetpeernameFN)_PR_InvalidStatus,
                                      (PRReservedFN)_PR_InvalidInt,
                                      (PRReservedFN)_PR_InvalidInt,
                                      (PRGetsocketoptionFN)_PR_InvalidStatus,
                                      (PRSetsocketoptionFN)_PR_InvalidStatus,
                                      (PRSendfileFN)_PR_InvalidInt,
                                      (PRConnectcontinueFN)_PR_InvalidStatus,
                                      (PRReservedFN)_PR_InvalidInt,
                                      (PRReservedFN)_PR_InvalidInt,
                                      (PRReservedFN)_PR_InvalidInt,
                                      (PRReservedFN)_PR_InvalidInt};

static PRIOMethods _pr_tcp_methods = {
   PR_DESC_SOCKET_TCP,
   pt_Close,
   pt_SocketRead,
   pt_SocketWrite,
   pt_Available_s,
   pt_Available64_s,
   pt_Synch,
   (PRSeekFN)_PR_InvalidInt,
   (PRSeek64FN)_PR_InvalidInt64,
   (PRFileInfoFN)_PR_InvalidStatus,
   (PRFileInfo64FN)_PR_InvalidStatus,
   pt_Writev,
   pt_Connect,
   pt_Accept,
   pt_Bind,
   pt_Listen,
   pt_Shutdown,
   pt_Recv,
   pt_Send,
   (PRRecvfromFN)_PR_InvalidInt,
#  if defined(LINUX) || defined(DARWIN)
   pt_TCP_SendTo, /* This is for TCP Fast Open. Linux uses SendTo function for
                     this. OSX uses connectx, but we imitate Linux. */
#  else
   (PRSendtoFN)_PR_InvalidInt,
#  endif
   pt_Poll,
   pt_AcceptRead,
   pt_TransmitFile,
   pt_GetSockName,
   pt_GetPeerName,
   (PRReservedFN)_PR_InvalidInt,
   (PRReservedFN)_PR_InvalidInt,
   pt_GetSocketOption,
   pt_SetSocketOption,
   pt_SendFile,
   pt_ConnectContinue,
   (PRReservedFN)_PR_InvalidInt,
   (PRReservedFN)_PR_InvalidInt,
   (PRReservedFN)_PR_InvalidInt,
   (PRReservedFN)_PR_InvalidInt};

static PRIOMethods _pr_udp_methods = {PR_DESC_SOCKET_UDP,
                                     pt_Close,
                                     pt_SocketRead,
                                     pt_SocketWrite,
                                     pt_Available_s,
                                     pt_Available64_s,
                                     pt_Synch,
                                     (PRSeekFN)_PR_InvalidInt,
                                     (PRSeek64FN)_PR_InvalidInt64,
                                     (PRFileInfoFN)_PR_InvalidStatus,
                                     (PRFileInfo64FN)_PR_InvalidStatus,
                                     pt_Writev,
                                     pt_Connect,
                                     (PRAcceptFN)_PR_InvalidDesc,
                                     pt_Bind,
                                     pt_Listen,
                                     pt_Shutdown,
                                     pt_Recv,
                                     pt_Send,
                                     pt_RecvFrom,
                                     pt_SendTo,
                                     pt_Poll,
                                     (PRAcceptreadFN)_PR_InvalidInt,
                                     (PRTransmitfileFN)_PR_InvalidInt,
                                     pt_GetSockName,
                                     pt_GetPeerName,
                                     (PRReservedFN)_PR_InvalidInt,
                                     (PRReservedFN)_PR_InvalidInt,
                                     pt_GetSocketOption,
                                     pt_SetSocketOption,
                                     (PRSendfileFN)_PR_InvalidInt,
                                     (PRConnectcontinueFN)_PR_InvalidStatus,
                                     (PRReservedFN)_PR_InvalidInt,
                                     (PRReservedFN)_PR_InvalidInt,
                                     (PRReservedFN)_PR_InvalidInt,
                                     (PRReservedFN)_PR_InvalidInt};

static PRIOMethods _pr_socketpollfd_methods = {
   (PRDescType)0,
   (PRCloseFN)_PR_InvalidStatus,
   (PRReadFN)_PR_InvalidInt,
   (PRWriteFN)_PR_InvalidInt,
   (PRAvailableFN)_PR_InvalidInt,
   (PRAvailable64FN)_PR_InvalidInt64,
   (PRFsyncFN)_PR_InvalidStatus,
   (PRSeekFN)_PR_InvalidInt,
   (PRSeek64FN)_PR_InvalidInt64,
   (PRFileInfoFN)_PR_InvalidStatus,
   (PRFileInfo64FN)_PR_InvalidStatus,
   (PRWritevFN)_PR_InvalidInt,
   (PRConnectFN)_PR_InvalidStatus,
   (PRAcceptFN)_PR_InvalidDesc,
   (PRBindFN)_PR_InvalidStatus,
   (PRListenFN)_PR_InvalidStatus,
   (PRShutdownFN)_PR_InvalidStatus,
   (PRRecvFN)_PR_InvalidInt,
   (PRSendFN)_PR_InvalidInt,
   (PRRecvfromFN)_PR_InvalidInt,
   (PRSendtoFN)_PR_InvalidInt,
   pt_Poll,
   (PRAcceptreadFN)_PR_InvalidInt,
   (PRTransmitfileFN)_PR_InvalidInt,
   (PRGetsocknameFN)_PR_InvalidStatus,
   (PRGetpeernameFN)_PR_InvalidStatus,
   (PRReservedFN)_PR_InvalidInt,
   (PRReservedFN)_PR_InvalidInt,
   (PRGetsocketoptionFN)_PR_InvalidStatus,
   (PRSetsocketoptionFN)_PR_InvalidStatus,
   (PRSendfileFN)_PR_InvalidInt,
   (PRConnectcontinueFN)_PR_InvalidStatus,
   (PRReservedFN)_PR_InvalidInt,
   (PRReservedFN)_PR_InvalidInt,
   (PRReservedFN)_PR_InvalidInt,
   (PRReservedFN)_PR_InvalidInt};

#  if defined(SOLARIS) || defined(LINUX) ||     \
     defined(__GNU__) || defined(__GLIBC__) || defined(AIX) ||  \
     defined(FREEBSD) || defined(NETBSD) || defined(OPENBSD) || \
     defined(NTO) || defined(DARWIN) || defined(RISCOS)
#    define _PR_FCNTL_FLAGS O_NONBLOCK
#  else
#    error "Can't determine architecture"
#  endif

/*
* Put a Unix file descriptor in non-blocking mode.
*/
static void pt_MakeFdNonblock(PRIntn osfd) {
 PRIntn flags;
 flags = fcntl(osfd, F_GETFL, 0);
 flags |= _PR_FCNTL_FLAGS;
 (void)fcntl(osfd, F_SETFL, flags);
}

/*
* Put a Unix socket fd in non-blocking mode that can
* ideally be inherited by an accepted socket.
*
* Why doesn't pt_MakeFdNonblock do?  This is to deal with
* the special case of HP-UX.  HP-UX has three kinds of
* non-blocking modes for sockets: the fcntl() O_NONBLOCK
* and O_NDELAY flags and ioctl() FIOSNBIO request.  Only
* the ioctl() FIOSNBIO form of non-blocking mode is
* inherited by an accepted socket.
*
* Other platforms just use the generic pt_MakeFdNonblock
* to put a socket in non-blocking mode.
*/
#    define pt_MakeSocketNonblock pt_MakeFdNonblock

static PRFileDesc* pt_SetMethods(PRIntn osfd, PRDescType type,
                                PRBool isAcceptedSocket, PRBool imported) {
 PRFileDesc* fd = _PR_Getfd();

 if (fd == NULL) {
   PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
 } else {
   fd->secret->md.osfd = osfd;
   fd->secret->state = _PR_FILEDESC_OPEN;
   if (imported) {
     fd->secret->inheritable = _PR_TRI_UNKNOWN;
   } else {
     /* By default, a Unix fd is not closed on exec. */
#  ifdef DEBUG
     PRIntn flags;
     flags = fcntl(osfd, F_GETFD, 0);
     PR_ASSERT(0 == flags);
#  endif
     fd->secret->inheritable = _PR_TRI_TRUE;
   }
   switch (type) {
     case PR_DESC_FILE:
       fd->methods = PR_GetFileMethods();
       break;
     case PR_DESC_SOCKET_TCP:
       fd->methods = PR_GetTCPMethods();
#  ifdef _PR_ACCEPT_INHERIT_NONBLOCK
       if (!isAcceptedSocket) {
         pt_MakeSocketNonblock(osfd);
       }
#  else
       pt_MakeSocketNonblock(osfd);
#  endif
       break;
     case PR_DESC_SOCKET_UDP:
       fd->methods = PR_GetUDPMethods();
       pt_MakeFdNonblock(osfd);
       break;
     case PR_DESC_PIPE:
       fd->methods = PR_GetPipeMethods();
       pt_MakeFdNonblock(osfd);
       break;
     default:
       break;
   }
 }
 return fd;
} /* pt_SetMethods */

PR_IMPLEMENT(const PRIOMethods*) PR_GetFileMethods(void) {
 return &_pr_file_methods;
} /* PR_GetFileMethods */

PR_IMPLEMENT(const PRIOMethods*) PR_GetPipeMethods(void) {
 return &_pr_pipe_methods;
} /* PR_GetPipeMethods */

PR_IMPLEMENT(const PRIOMethods*) PR_GetTCPMethods(void) {
 return &_pr_tcp_methods;
} /* PR_GetTCPMethods */

PR_IMPLEMENT(const PRIOMethods*) PR_GetUDPMethods(void) {
 return &_pr_udp_methods;
} /* PR_GetUDPMethods */

static const PRIOMethods* PR_GetSocketPollFdMethods(void) {
 return &_pr_socketpollfd_methods;
} /* PR_GetSocketPollFdMethods */

PR_IMPLEMENT(PRFileDesc*)
PR_AllocFileDesc(PRInt32 osfd, const PRIOMethods* methods) {
 PRFileDesc* fd = _PR_Getfd();

 if (NULL == fd) {
   goto failed;
 }

 fd->methods = methods;
 fd->secret->md.osfd = osfd;
 /* Make fd non-blocking */
 if (osfd > 2) {
   /* Don't mess around with stdin, stdout or stderr */
   if (&_pr_tcp_methods == methods) {
     pt_MakeSocketNonblock(osfd);
   } else {
     pt_MakeFdNonblock(osfd);
   }
 }
 fd->secret->state = _PR_FILEDESC_OPEN;
 fd->secret->inheritable = _PR_TRI_UNKNOWN;
 return fd;

failed:
 PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
 return fd;
} /* PR_AllocFileDesc */

#  if !defined(_PR_INET6) || defined(_PR_INET6_PROBE)
PR_EXTERN(PRStatus) _pr_push_ipv6toipv4_layer(PRFileDesc* fd);
#    if defined(_PR_INET6_PROBE)
extern PRBool _pr_ipv6_is_present(void);
PR_IMPLEMENT(PRBool) _pr_test_ipv6_socket() {
 int osfd;

#      if defined(DARWIN)
 /*
  * Disable IPv6 if Darwin version is less than 7.0.0 (OS X 10.3).  IPv6 on
  * lesser versions is not ready for general use (see bug 222031).
  */
 {
   struct utsname u;
   if (uname(&u) != 0 || atoi(u.release) < 7) {
     return PR_FALSE;
   }
 }
#      endif

 /*
  * HP-UX only: HP-UX IPv6 Porting Guide (dated February 2001)
  * suggests that we call open("/dev/ip6", O_RDWR) to determine
  * whether IPv6 APIs and the IPv6 stack are on the system.
  * Our portable test below seems to work fine, so I am using it.
  */
 osfd = socket(AF_INET6, SOCK_STREAM, 0);
 if (osfd != -1) {
   close(osfd);
   return PR_TRUE;
 }
 return PR_FALSE;
}
#    endif /* _PR_INET6_PROBE */
#  endif

PR_IMPLEMENT(PRFileDesc*)
PR_Socket(PRInt32 domain, PRInt32 type, PRInt32 proto) {
 PRIntn osfd;
 PRDescType ftype;
 PRFileDesc* fd = NULL;
#  if defined(_PR_INET6_PROBE) || !defined(_PR_INET6)
 PRInt32 tmp_domain = domain;
#  endif

 if (!_pr_initialized) {
   _PR_ImplicitInitialization();
 }

 if (pt_TestAbort()) {
   return NULL;
 }

 if (PF_INET != domain && PR_AF_INET6 != domain
#  if defined(_PR_HAVE_SDP)
     && PR_AF_INET_SDP != domain
#    if defined(SOLARIS)
     && PR_AF_INET6_SDP != domain
#    endif /* SOLARIS */
#  endif   /* _PR_HAVE_SDP */
     && PF_UNIX != domain) {
   PR_SetError(PR_ADDRESS_NOT_SUPPORTED_ERROR, 0);
   return fd;
 }
 if (type == SOCK_STREAM) {
   ftype = PR_DESC_SOCKET_TCP;
 } else if (type == SOCK_DGRAM) {
   ftype = PR_DESC_SOCKET_UDP;
 } else {
   (void)PR_SetError(PR_ADDRESS_NOT_SUPPORTED_ERROR, 0);
   return fd;
 }
#  if defined(_PR_HAVE_SDP)
#    if defined(LINUX)
 if (PR_AF_INET_SDP == domain) {
   domain = AF_INET_SDP;
 }
#    elif defined(SOLARIS)
 if (PR_AF_INET_SDP == domain) {
   domain = AF_INET;
   proto = PROTO_SDP;
 } else if (PR_AF_INET6_SDP == domain) {
   domain = AF_INET6;
   proto = PROTO_SDP;
 }
#    endif /* SOLARIS */
#  endif   /* _PR_HAVE_SDP */
#  if defined(_PR_INET6_PROBE)
 if (PR_AF_INET6 == domain) {
   domain = _pr_ipv6_is_present() ? AF_INET6 : AF_INET;
 }
#  elif defined(_PR_INET6)
 if (PR_AF_INET6 == domain) {
   domain = AF_INET6;
 }
#  else
 if (PR_AF_INET6 == domain) {
   domain = AF_INET;
 }
#  endif

 osfd = socket(domain, type, proto);
 if (osfd == -1) {
   pt_MapError(_PR_MD_MAP_SOCKET_ERROR, errno);
 } else {
#  ifdef _PR_IPV6_V6ONLY_PROBE
   if ((domain == AF_INET6) && _pr_ipv6_v6only_on_by_default) {
     int on = 0;
     (void)setsockopt(osfd, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on));
   }
#  endif
   fd = pt_SetMethods(osfd, ftype, PR_FALSE, PR_FALSE);
   if (fd == NULL) {
     close(osfd);
   }
 }
#  ifdef _PR_NEED_SECRET_AF
 if (fd != NULL) {
   fd->secret->af = domain;
 }
#  endif
#  if defined(_PR_INET6_PROBE) || !defined(_PR_INET6)
 if (fd != NULL) {
   /*
    * For platforms with no support for IPv6
    * create layered socket for IPv4-mapped IPv6 addresses
    */
   if (PR_AF_INET6 == tmp_domain && PR_AF_INET == domain) {
     if (PR_FAILURE == _pr_push_ipv6toipv4_layer(fd)) {
       PR_Close(fd);
       fd = NULL;
     }
   }
 }
#  endif
 return fd;
} /* PR_Socket */

/*****************************************************************************/
/****************************** I/O public methods ***************************/
/*****************************************************************************/

PR_IMPLEMENT(PRFileDesc*)
PR_OpenFile(const char* name, PRIntn flags, PRIntn mode) {
 PRFileDesc* fd = NULL;
 PRIntn syserrno, osfd = -1, osflags = 0;
 ;

 if (!_pr_initialized) {
   _PR_ImplicitInitialization();
 }

 if (pt_TestAbort()) {
   return NULL;
 }

 if (flags & PR_RDONLY) {
   osflags |= O_RDONLY;
 }
 if (flags & PR_WRONLY) {
   osflags |= O_WRONLY;
 }
 if (flags & PR_RDWR) {
   osflags |= O_RDWR;
 }
 if (flags & PR_APPEND) {
   osflags |= O_APPEND;
 }
 if (flags & PR_TRUNCATE) {
   osflags |= O_TRUNC;
 }
 if (flags & PR_EXCL) {
   osflags |= O_EXCL;
 }
 if (flags & PR_SYNC) {
#  if defined(O_SYNC)
   osflags |= O_SYNC;
#  elif defined(O_FSYNC)
   osflags |= O_FSYNC;
#  else
#    error "Neither O_SYNC nor O_FSYNC is defined on this platform"
#  endif
 }

 /*
 ** We have to hold the lock across the creation in order to
 ** enforce the sematics of PR_Rename(). (see the latter for
 ** more details)
 */
 if (flags & PR_CREATE_FILE) {
   osflags |= O_CREAT;
   if (NULL != _pr_rename_lock) {
     PR_Lock(_pr_rename_lock);
   }
 }

 osfd = _md_iovector._open64(name, osflags, mode);
 syserrno = errno;

 if ((flags & PR_CREATE_FILE) && (NULL != _pr_rename_lock)) {
   PR_Unlock(_pr_rename_lock);
 }

 if (osfd == -1) {
   pt_MapError(_PR_MD_MAP_OPEN_ERROR, syserrno);
 } else {
   fd = pt_SetMethods(osfd, PR_DESC_FILE, PR_FALSE, PR_FALSE);
   if (fd == NULL) {
     close(osfd); /* $$$ whoops! this is bad $$$ */
   }
 }
 return fd;
} /* PR_OpenFile */

PR_IMPLEMENT(PRFileDesc*) PR_Open(const char* name, PRIntn flags, PRIntn mode) {
 return PR_OpenFile(name, flags, mode);
} /* PR_Open */

PR_IMPLEMENT(PRStatus) PR_Delete(const char* name) {
 PRIntn rv = -1;

 if (!_pr_initialized) {
   _PR_ImplicitInitialization();
 }

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 rv = unlink(name);

 if (rv == -1) {
   pt_MapError(_PR_MD_MAP_UNLINK_ERROR, errno);
   return PR_FAILURE;
 }
 return PR_SUCCESS;
} /* PR_Delete */

PR_IMPLEMENT(PRStatus) PR_Access(const char* name, PRAccessHow how) {
 PRIntn rv;

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 switch (how) {
   case PR_ACCESS_READ_OK:
     rv = access(name, R_OK);
     break;
   case PR_ACCESS_WRITE_OK:
     rv = access(name, W_OK);
     break;
   case PR_ACCESS_EXISTS:
   default:
     rv = access(name, F_OK);
 }
 if (0 == rv) {
   return PR_SUCCESS;
 }
 pt_MapError(_PR_MD_MAP_ACCESS_ERROR, errno);
 return PR_FAILURE;

} /* PR_Access */

PR_IMPLEMENT(PRStatus) PR_GetFileInfo(const char* fn, PRFileInfo* info) {
 PRInt32 rv = _PR_MD_GETFILEINFO(fn, info);
 return (0 == rv) ? PR_SUCCESS : PR_FAILURE;
} /* PR_GetFileInfo */

PR_IMPLEMENT(PRStatus) PR_GetFileInfo64(const char* fn, PRFileInfo64* info) {
 PRInt32 rv;

 if (!_pr_initialized) {
   _PR_ImplicitInitialization();
 }
 rv = _PR_MD_GETFILEINFO64(fn, info);
 return (0 == rv) ? PR_SUCCESS : PR_FAILURE;
} /* PR_GetFileInfo64 */

PR_IMPLEMENT(PRStatus) PR_Rename(const char* from, const char* to) {
 PRIntn rv = -1;

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 /*
 ** We have to acquire a lock here to stiffle anybody trying to create
 ** a new file at the same time. And we have to hold that lock while we
 ** test to see if the file exists and do the rename. The other place
 ** where the lock is held is in PR_Open() when possibly creating a
 ** new file.
 */

 PR_Lock(_pr_rename_lock);
 rv = access(to, F_OK);
 if (0 == rv) {
   PR_SetError(PR_FILE_EXISTS_ERROR, 0);
   rv = -1;
 } else {
   rv = rename(from, to);
   if (rv == -1) {
     pt_MapError(_PR_MD_MAP_RENAME_ERROR, errno);
   }
 }
 PR_Unlock(_pr_rename_lock);
 return (-1 == rv) ? PR_FAILURE : PR_SUCCESS;
} /* PR_Rename */

PR_IMPLEMENT(PRStatus) PR_CloseDir(PRDir* dir) {
 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 if (NULL != dir->md.d) {
   if (closedir(dir->md.d) == -1) {
     _PR_MD_MAP_CLOSEDIR_ERROR(errno);
     return PR_FAILURE;
   }
   dir->md.d = NULL;
   PR_DELETE(dir);
 }
 return PR_SUCCESS;
} /* PR_CloseDir */

PR_IMPLEMENT(PRStatus) PR_MakeDir(const char* name, PRIntn mode) {
 PRInt32 rv = -1;

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 /*
 ** This lock is used to enforce rename semantics as described
 ** in PR_Rename.
 */
 if (NULL != _pr_rename_lock) {
   PR_Lock(_pr_rename_lock);
 }
 rv = mkdir(name, mode);
 if (-1 == rv) {
   pt_MapError(_PR_MD_MAP_MKDIR_ERROR, errno);
 }
 if (NULL != _pr_rename_lock) {
   PR_Unlock(_pr_rename_lock);
 }

 return (-1 == rv) ? PR_FAILURE : PR_SUCCESS;
} /* PR_Makedir */

PR_IMPLEMENT(PRStatus) PR_MkDir(const char* name, PRIntn mode) {
 return PR_MakeDir(name, mode);
} /* PR_Mkdir */

PR_IMPLEMENT(PRStatus) PR_RmDir(const char* name) {
 PRInt32 rv;

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 rv = rmdir(name);
 if (0 == rv) {
   return PR_SUCCESS;
 }
 pt_MapError(_PR_MD_MAP_RMDIR_ERROR, errno);
 return PR_FAILURE;
} /* PR_Rmdir */

PR_IMPLEMENT(PRDir*) PR_OpenDir(const char* name) {
 DIR* osdir;
 PRDir* dir = NULL;

 if (pt_TestAbort()) {
   return dir;
 }

 osdir = opendir(name);
 if (osdir == NULL) {
   pt_MapError(_PR_MD_MAP_OPENDIR_ERROR, errno);
 } else {
   dir = PR_NEWZAP(PRDir);
   if (dir) {
     dir->md.d = osdir;
   } else {
     (void)closedir(osdir);
   }
 }
 return dir;
} /* PR_OpenDir */

static PRInt32 _pr_poll_with_poll(PRPollDesc* pds, PRIntn npds,
                                 PRIntervalTime timeout) {
 PRInt32 ready = 0;
 /*
  * For restarting poll() if it is interrupted by a signal.
  * We use these variables to figure out how much time has
  * elapsed and how much of the timeout still remains.
  */
 PRIntervalTime start = 0, elapsed, remaining;

 if (pt_TestAbort()) {
   return -1;
 }

 if (0 == npds) {
   PR_Sleep(timeout);
 } else {
#  define STACK_POLL_DESC_COUNT 64
   struct pollfd stack_syspoll[STACK_POLL_DESC_COUNT];
   struct pollfd* syspoll;
   PRIntn index, msecs;

   if (npds <= STACK_POLL_DESC_COUNT) {
     syspoll = stack_syspoll;
   } else {
     PRThread* me = PR_GetCurrentThread();
     if (npds > me->syspoll_count) {
       PR_Free(me->syspoll_list);
       me->syspoll_list =
           (struct pollfd*)PR_MALLOC(npds * sizeof(struct pollfd));
       if (NULL == me->syspoll_list) {
         me->syspoll_count = 0;
         PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
         return -1;
       }
       me->syspoll_count = npds;
     }
     syspoll = me->syspoll_list;
   }

   for (index = 0; index < npds; ++index) {
     PRInt16 in_flags_read = 0, in_flags_write = 0;
     PRInt16 out_flags_read = 0, out_flags_write = 0;

     if ((NULL != pds[index].fd) && (0 != pds[index].in_flags)) {
       if (pds[index].in_flags & PR_POLL_READ) {
         in_flags_read = (pds[index].fd->methods->poll)(
             pds[index].fd, pds[index].in_flags & ~PR_POLL_WRITE,
             &out_flags_read);
       }
       if (pds[index].in_flags & PR_POLL_WRITE) {
         in_flags_write = (pds[index].fd->methods->poll)(
             pds[index].fd, pds[index].in_flags & ~PR_POLL_READ,
             &out_flags_write);
       }
       if ((0 != (in_flags_read & out_flags_read)) ||
           (0 != (in_flags_write & out_flags_write))) {
         /* this one is ready right now */
         if (0 == ready) {
           /*
            * We will return without calling the system
            * poll function.  So zero the out_flags
            * fields of all the poll descriptors before
            * this one.
            */
           int i;
           for (i = 0; i < index; i++) {
             pds[i].out_flags = 0;
           }
         }
         ready += 1;
         pds[index].out_flags = out_flags_read | out_flags_write;
       } else {
         /* now locate the NSPR layer at the bottom of the stack */
         PRFileDesc* bottom =
             PR_GetIdentitiesLayer(pds[index].fd, PR_NSPR_IO_LAYER);
         /* ignore a socket without PR_NSPR_IO_LAYER available */

         pds[index].out_flags = 0; /* pre-condition */
         if ((NULL != bottom) &&
             (_PR_FILEDESC_OPEN == bottom->secret->state)) {
           if (0 == ready) {
             syspoll[index].fd = bottom->secret->md.osfd;
             syspoll[index].events = 0;
             if (in_flags_read & PR_POLL_READ) {
               pds[index].out_flags |= _PR_POLL_READ_SYS_READ;
               syspoll[index].events |= POLLIN;
             }
             if (in_flags_read & PR_POLL_WRITE) {
               pds[index].out_flags |= _PR_POLL_READ_SYS_WRITE;
               syspoll[index].events |= POLLOUT;
             }
             if (in_flags_write & PR_POLL_READ) {
               pds[index].out_flags |= _PR_POLL_WRITE_SYS_READ;
               syspoll[index].events |= POLLIN;
             }
             if (in_flags_write & PR_POLL_WRITE) {
               pds[index].out_flags |= _PR_POLL_WRITE_SYS_WRITE;
               syspoll[index].events |= POLLOUT;
             }
             if (pds[index].in_flags & PR_POLL_EXCEPT) {
               syspoll[index].events |= POLLPRI;
             }
           }
         } else {
           if (0 == ready) {
             int i;
             for (i = 0; i < index; i++) {
               pds[i].out_flags = 0;
             }
           }
           ready += 1; /* this will cause an abrupt return */
           pds[index].out_flags = PR_POLL_NVAL; /* bogii */
         }
       }
     } else {
       /* make poll() ignore this entry */
       syspoll[index].fd = -1;
       syspoll[index].events = 0;
       pds[index].out_flags = 0;
     }
   }
   if (0 == ready) {
     switch (timeout) {
       case PR_INTERVAL_NO_WAIT:
         msecs = 0;
         break;
       case PR_INTERVAL_NO_TIMEOUT:
         msecs = -1;
         break;
       default:
         msecs = PR_IntervalToMilliseconds(timeout);
         start = PR_IntervalNow();
     }

   retry:
     ready = poll(syspoll, npds, msecs);
     if (-1 == ready) {
       PRIntn oserror = errno;

       if (EINTR == oserror) {
         if (timeout == PR_INTERVAL_NO_TIMEOUT) {
           goto retry;
         } else if (timeout == PR_INTERVAL_NO_WAIT) {
           ready = 0; /* don't retry, just time out */
         } else {
           elapsed = (PRIntervalTime)(PR_IntervalNow() - start);
           if (elapsed > timeout) {
             ready = 0; /* timed out */
           } else {
             remaining = timeout - elapsed;
             msecs = PR_IntervalToMilliseconds(remaining);
             goto retry;
           }
         }
       } else {
         _PR_MD_MAP_POLL_ERROR(oserror);
       }
     } else if (ready > 0) {
       for (index = 0; index < npds; ++index) {
         PRInt16 out_flags = 0;
         if ((NULL != pds[index].fd) && (0 != pds[index].in_flags)) {
           if (0 != syspoll[index].revents) {
             if (syspoll[index].revents & POLLIN) {
               if (pds[index].out_flags & _PR_POLL_READ_SYS_READ) {
                 out_flags |= PR_POLL_READ;
               }
               if (pds[index].out_flags & _PR_POLL_WRITE_SYS_READ) {
                 out_flags |= PR_POLL_WRITE;
               }
             }
             if (syspoll[index].revents & POLLOUT) {
               if (pds[index].out_flags & _PR_POLL_READ_SYS_WRITE) {
                 out_flags |= PR_POLL_READ;
               }
               if (pds[index].out_flags & _PR_POLL_WRITE_SYS_WRITE) {
                 out_flags |= PR_POLL_WRITE;
               }
             }
             if (syspoll[index].revents & POLLPRI) {
               out_flags |= PR_POLL_EXCEPT;
             }
             if (syspoll[index].revents & POLLERR) {
               out_flags |= PR_POLL_ERR;
             }
             if (syspoll[index].revents & POLLNVAL) {
               out_flags |= PR_POLL_NVAL;
             }
             if (syspoll[index].revents & POLLHUP) {
               out_flags |= PR_POLL_HUP;
             }
           }
         }
         pds[index].out_flags = out_flags;
       }
     }
   }
 }
 return ready;

} /* _pr_poll_with_poll */


PR_IMPLEMENT(PRInt32)
PR_Poll(PRPollDesc* pds, PRIntn npds, PRIntervalTime timeout) {
 return (_pr_poll_with_poll(pds, npds, timeout));
}

PR_IMPLEMENT(PRDirEntry*) PR_ReadDir(PRDir* dir, PRDirFlags flags) {
 struct dirent* dp;

 if (pt_TestAbort()) {
   return NULL;
 }

 for (;;) {
   errno = 0;
   dp = readdir(dir->md.d);
   if (NULL == dp) {
     pt_MapError(_PR_MD_MAP_READDIR_ERROR, errno);
     return NULL;
   }
   if ((flags & PR_SKIP_DOT) && ('.' == dp->d_name[0]) &&
       (0 == dp->d_name[1])) {
     continue;
   }
   if ((flags & PR_SKIP_DOT_DOT) && ('.' == dp->d_name[0]) &&
       ('.' == dp->d_name[1]) && (0 == dp->d_name[2])) {
     continue;
   }
   if ((flags & PR_SKIP_HIDDEN) && ('.' == dp->d_name[0])) {
     continue;
   }
   break;
 }
 dir->d.name = dp->d_name;
 return &dir->d;
} /* PR_ReadDir */

PR_IMPLEMENT(PRFileDesc*) PR_NewUDPSocket(void) {
 PRIntn domain = PF_INET;

 return PR_Socket(domain, SOCK_DGRAM, 0);
} /* PR_NewUDPSocket */

PR_IMPLEMENT(PRFileDesc*) PR_NewTCPSocket(void) {
 PRIntn domain = PF_INET;

 return PR_Socket(domain, SOCK_STREAM, 0);
} /* PR_NewTCPSocket */

PR_IMPLEMENT(PRFileDesc*) PR_OpenUDPSocket(PRIntn af) {
 return PR_Socket(af, SOCK_DGRAM, 0);
} /* PR_NewUDPSocket */

PR_IMPLEMENT(PRFileDesc*) PR_OpenTCPSocket(PRIntn af) {
 return PR_Socket(af, SOCK_STREAM, 0);
} /* PR_NewTCPSocket */

PR_IMPLEMENT(PRStatus) PR_NewTCPSocketPair(PRFileDesc* fds[2]) {
 PRInt32 osfd[2];

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 if (socketpair(AF_UNIX, SOCK_STREAM, 0, osfd) == -1) {
   pt_MapError(_PR_MD_MAP_SOCKETPAIR_ERROR, errno);
   return PR_FAILURE;
 }

 fds[0] = pt_SetMethods(osfd[0], PR_DESC_SOCKET_TCP, PR_FALSE, PR_FALSE);
 if (fds[0] == NULL) {
   close(osfd[0]);
   close(osfd[1]);
   return PR_FAILURE;
 }
 fds[1] = pt_SetMethods(osfd[1], PR_DESC_SOCKET_TCP, PR_FALSE, PR_FALSE);
 if (fds[1] == NULL) {
   PR_Close(fds[0]);
   close(osfd[1]);
   return PR_FAILURE;
 }
 return PR_SUCCESS;
} /* PR_NewTCPSocketPair */

PR_IMPLEMENT(PRStatus)
PR_CreatePipe(PRFileDesc** readPipe, PRFileDesc** writePipe) {
 int pipefd[2];

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 if (pipe(pipefd) == -1) {
   /* XXX map pipe error */
   PR_SetError(PR_UNKNOWN_ERROR, errno);
   return PR_FAILURE;
 }
 *readPipe = pt_SetMethods(pipefd[0], PR_DESC_PIPE, PR_FALSE, PR_FALSE);
 if (NULL == *readPipe) {
   close(pipefd[0]);
   close(pipefd[1]);
   return PR_FAILURE;
 }
 *writePipe = pt_SetMethods(pipefd[1], PR_DESC_PIPE, PR_FALSE, PR_FALSE);
 if (NULL == *writePipe) {
   PR_Close(*readPipe);
   close(pipefd[1]);
   return PR_FAILURE;
 }
 return PR_SUCCESS;
}

/*
** Set the inheritance attribute of a file descriptor.
*/
PR_IMPLEMENT(PRStatus) PR_SetFDInheritable(PRFileDesc* fd, PRBool inheritable) {
 /*
  * Only a non-layered, NSPR file descriptor can be inherited
  * by a child process.
  */
 if (fd->identity != PR_NSPR_IO_LAYER) {
   PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
   return PR_FAILURE;
 }
 if (fd->secret->inheritable != inheritable) {
   if (fcntl(fd->secret->md.osfd, F_SETFD, inheritable ? 0 : FD_CLOEXEC) ==
       -1) {
     _PR_MD_MAP_DEFAULT_ERROR(errno);
     return PR_FAILURE;
   }
   fd->secret->inheritable = (_PRTriStateBool)inheritable;
 }
 return PR_SUCCESS;
}

/*****************************************************************************/
/***************************** I/O friends methods ***************************/
/*****************************************************************************/

PR_IMPLEMENT(PRFileDesc*) PR_ImportFile(PRInt32 osfd) {
 PRFileDesc* fd;

 if (!_pr_initialized) {
   _PR_ImplicitInitialization();
 }
 fd = pt_SetMethods(osfd, PR_DESC_FILE, PR_FALSE, PR_TRUE);
 if (NULL == fd) {
   close(osfd);
 }
 return fd;
} /* PR_ImportFile */

PR_IMPLEMENT(PRFileDesc*) PR_ImportPipe(PRInt32 osfd) {
 PRFileDesc* fd;

 if (!_pr_initialized) {
   _PR_ImplicitInitialization();
 }
 fd = pt_SetMethods(osfd, PR_DESC_PIPE, PR_FALSE, PR_TRUE);
 if (NULL == fd) {
   close(osfd);
 }
 return fd;
} /* PR_ImportPipe */

PR_IMPLEMENT(PRFileDesc*) PR_ImportTCPSocket(PRInt32 osfd) {
 PRFileDesc* fd;

 if (!_pr_initialized) {
   _PR_ImplicitInitialization();
 }
 fd = pt_SetMethods(osfd, PR_DESC_SOCKET_TCP, PR_FALSE, PR_TRUE);
 if (NULL == fd) {
   close(osfd);
 }
#  ifdef _PR_NEED_SECRET_AF
 if (NULL != fd) {
   fd->secret->af = PF_INET;
 }
#  endif
 return fd;
} /* PR_ImportTCPSocket */

PR_IMPLEMENT(PRFileDesc*) PR_ImportUDPSocket(PRInt32 osfd) {
 PRFileDesc* fd;

 if (!_pr_initialized) {
   _PR_ImplicitInitialization();
 }
 fd = pt_SetMethods(osfd, PR_DESC_SOCKET_UDP, PR_FALSE, PR_TRUE);
 if (NULL == fd) {
   close(osfd);
 }
 return fd;
} /* PR_ImportUDPSocket */

PR_IMPLEMENT(PRFileDesc*) PR_CreateSocketPollFd(PRInt32 osfd) {
 PRFileDesc* fd;

 if (!_pr_initialized) {
   _PR_ImplicitInitialization();
 }

 fd = _PR_Getfd();

 if (fd == NULL) {
   PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
 } else {
   fd->secret->md.osfd = osfd;
   fd->secret->inheritable = _PR_TRI_FALSE;
   fd->secret->state = _PR_FILEDESC_OPEN;
   fd->methods = PR_GetSocketPollFdMethods();
 }

 return fd;
} /* PR_CreateSocketPollFD */

PR_IMPLEMENT(PRStatus) PR_DestroySocketPollFd(PRFileDesc* fd) {
 if (NULL == fd) {
   PR_SetError(PR_BAD_DESCRIPTOR_ERROR, 0);
   return PR_FAILURE;
 }
 fd->secret->state = _PR_FILEDESC_CLOSED;
 _PR_Putfd(fd);
 return PR_SUCCESS;
} /* PR_DestroySocketPollFd */

PR_IMPLEMENT(PRInt32) PR_FileDesc2NativeHandle(PRFileDesc* bottom) {
 PRInt32 osfd = -1;
 bottom =
     (NULL == bottom) ? NULL : PR_GetIdentitiesLayer(bottom, PR_NSPR_IO_LAYER);
 if (NULL == bottom) {
   PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
 } else {
   osfd = bottom->secret->md.osfd;
 }
 return osfd;
} /* PR_FileDesc2NativeHandle */

PR_IMPLEMENT(void)
PR_ChangeFileDescNativeHandle(PRFileDesc* fd, PRInt32 handle) {
 if (fd) {
   fd->secret->md.osfd = handle;
 }
} /*  PR_ChangeFileDescNativeHandle*/

PR_IMPLEMENT(PRStatus) PR_LockFile(PRFileDesc* fd) {
 PRStatus status = PR_SUCCESS;

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 PR_Lock(_pr_flock_lock);
 while (-1 == fd->secret->lockCount) {
   PR_WaitCondVar(_pr_flock_cv, PR_INTERVAL_NO_TIMEOUT);
 }
 if (0 == fd->secret->lockCount) {
   fd->secret->lockCount = -1;
   PR_Unlock(_pr_flock_lock);
   status = _PR_MD_LOCKFILE(fd->secret->md.osfd);
   PR_Lock(_pr_flock_lock);
   fd->secret->lockCount = (PR_SUCCESS == status) ? 1 : 0;
   PR_NotifyAllCondVar(_pr_flock_cv);
 } else {
   fd->secret->lockCount += 1;
 }
 PR_Unlock(_pr_flock_lock);

 return status;
} /* PR_LockFile */

PR_IMPLEMENT(PRStatus) PR_TLockFile(PRFileDesc* fd) {
 PRStatus status = PR_SUCCESS;

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 PR_Lock(_pr_flock_lock);
 if (0 == fd->secret->lockCount) {
   status = _PR_MD_TLOCKFILE(fd->secret->md.osfd);
   if (PR_SUCCESS == status) {
     fd->secret->lockCount = 1;
   }
 } else {
   fd->secret->lockCount += 1;
 }
 PR_Unlock(_pr_flock_lock);

 return status;
} /* PR_TLockFile */

PR_IMPLEMENT(PRStatus) PR_UnlockFile(PRFileDesc* fd) {
 PRStatus status = PR_SUCCESS;

 if (pt_TestAbort()) {
   return PR_FAILURE;
 }

 PR_Lock(_pr_flock_lock);
 if (fd->secret->lockCount == 1) {
   status = _PR_MD_UNLOCKFILE(fd->secret->md.osfd);
   if (PR_SUCCESS == status) {
     fd->secret->lockCount = 0;
   }
 } else {
   fd->secret->lockCount -= 1;
 }
 PR_Unlock(_pr_flock_lock);

 return status;
}

/*
* The next two entry points should not be in the API, but they are
* defined here for historical (or hysterical) reasons.
*/

PR_IMPLEMENT(PRInt32) PR_GetSysfdTableMax(void) {
#  if defined(AIX)
 return sysconf(_SC_OPEN_MAX);
#  else
 struct rlimit rlim;

 if (getrlimit(RLIMIT_NOFILE, &rlim) < 0) {
   return -1;
 }

 return rlim.rlim_max;
#  endif
}

PR_IMPLEMENT(PRInt32) PR_SetSysfdTableSize(PRIntn table_size) {
#  if defined(AIX)
 return -1;
#  else
 struct rlimit rlim;
 PRInt32 tableMax = PR_GetSysfdTableMax();

 if (tableMax < 0) {
   return -1;
 }
 rlim.rlim_max = tableMax;

 /* Grow as much as we can; even if too big */
 if (rlim.rlim_max < table_size) {
   rlim.rlim_cur = rlim.rlim_max;
 } else {
   rlim.rlim_cur = table_size;
 }

 if (setrlimit(RLIMIT_NOFILE, &rlim) < 0) {
   return -1;
 }

 return rlim.rlim_cur;
#  endif
}

/*
* PR_Stat is supported for backward compatibility; some existing Java
* code uses it.  New code should use PR_GetFileInfo.
*/

#  ifndef NO_NSPR_10_SUPPORT
PR_IMPLEMENT(PRInt32) PR_Stat(const char* name, struct stat* buf) {
 static PRBool unwarned = PR_TRUE;
 if (unwarned) {
   unwarned = _PR_Obsolete("PR_Stat", "PR_GetFileInfo");
 }

 if (pt_TestAbort()) {
   return -1;
 }

 if (-1 == stat(name, buf)) {
   pt_MapError(_PR_MD_MAP_STAT_ERROR, errno);
   return -1;
 } else {
   return 0;
 }
}
#  endif /* ! NO_NSPR_10_SUPPORT */

PR_IMPLEMENT(void) PR_FD_ZERO(PR_fd_set* set) {
 static PRBool unwarned = PR_TRUE;
 if (unwarned) {
   unwarned = _PR_Obsolete("PR_FD_ZERO (PR_Select)", "PR_Poll");
 }
 memset(set, 0, sizeof(PR_fd_set));
}

PR_IMPLEMENT(void) PR_FD_SET(PRFileDesc* fh, PR_fd_set* set) {
 static PRBool unwarned = PR_TRUE;
 if (unwarned) {
   unwarned = _PR_Obsolete("PR_FD_SET (PR_Select)", "PR_Poll");
 }
 PR_ASSERT(set->hsize < PR_MAX_SELECT_DESC);

 set->harray[set->hsize++] = fh;
}

PR_IMPLEMENT(void) PR_FD_CLR(PRFileDesc* fh, PR_fd_set* set) {
 PRUint32 index, index2;
 static PRBool unwarned = PR_TRUE;
 if (unwarned) {
   unwarned = _PR_Obsolete("PR_FD_CLR (PR_Select)", "PR_Poll");
 }

 for (index = 0; index < set->hsize; index++)
   if (set->harray[index] == fh) {
     for (index2 = index; index2 < (set->hsize - 1); index2++) {
       set->harray[index2] = set->harray[index2 + 1];
     }
     set->hsize--;
     break;
   }
}

PR_IMPLEMENT(PRInt32) PR_FD_ISSET(PRFileDesc* fh, PR_fd_set* set) {
 PRUint32 index;
 static PRBool unwarned = PR_TRUE;
 if (unwarned) {
   unwarned = _PR_Obsolete("PR_FD_ISSET (PR_Select)", "PR_Poll");
 }
 for (index = 0; index < set->hsize; index++)
   if (set->harray[index] == fh) {
     return 1;
   }
 return 0;
}

PR_IMPLEMENT(void) PR_FD_NSET(PRInt32 fd, PR_fd_set* set) {
 static PRBool unwarned = PR_TRUE;
 if (unwarned) {
   unwarned = _PR_Obsolete("PR_FD_NSET (PR_Select)", "PR_Poll");
 }
 PR_ASSERT(set->nsize < PR_MAX_SELECT_DESC);

 set->narray[set->nsize++] = fd;
}

PR_IMPLEMENT(void) PR_FD_NCLR(PRInt32 fd, PR_fd_set* set) {
 PRUint32 index, index2;
 static PRBool unwarned = PR_TRUE;
 if (unwarned) {
   unwarned = _PR_Obsolete("PR_FD_NCLR (PR_Select)", "PR_Poll");
 }

 for (index = 0; index < set->nsize; index++)
   if (set->narray[index] == fd) {
     for (index2 = index; index2 < (set->nsize - 1); index2++) {
       set->narray[index2] = set->narray[index2 + 1];
     }
     set->nsize--;
     break;
   }
}

PR_IMPLEMENT(PRInt32) PR_FD_NISSET(PRInt32 fd, PR_fd_set* set) {
 PRUint32 index;
 static PRBool unwarned = PR_TRUE;
 if (unwarned) {
   unwarned = _PR_Obsolete("PR_FD_NISSET (PR_Select)", "PR_Poll");
 }
 for (index = 0; index < set->nsize; index++)
   if (set->narray[index] == fd) {
     return 1;
   }
 return 0;
}

#  include <sys/types.h>
#  include <sys/time.h>
#  if !defined(LINUX) && !defined(__GNU__) && \
     !defined(__GLIBC__)
#    include <sys/select.h>
#  endif

static PRInt32 _PR_getset(PR_fd_set* pr_set, fd_set* set) {
 PRUint32 index;
 PRInt32 max = 0;

 if (!pr_set) {
   return 0;
 }

 FD_ZERO(set);

 /* First set the pr file handle osfds */
 for (index = 0; index < pr_set->hsize; index++) {
   FD_SET(pr_set->harray[index]->secret->md.osfd, set);
   if (pr_set->harray[index]->secret->md.osfd > max) {
     max = pr_set->harray[index]->secret->md.osfd;
   }
 }
 /* Second set the native osfds */
 for (index = 0; index < pr_set->nsize; index++) {
   FD_SET(pr_set->narray[index], set);
   if (pr_set->narray[index] > max) {
     max = pr_set->narray[index];
   }
 }
 return max;
}

static void _PR_setset(PR_fd_set* pr_set, fd_set* set) {
 PRUint32 index, last_used;

 if (!pr_set) {
   return;
 }

 for (last_used = 0, index = 0; index < pr_set->hsize; index++) {
   if (FD_ISSET(pr_set->harray[index]->secret->md.osfd, set)) {
     pr_set->harray[last_used++] = pr_set->harray[index];
   }
 }
 pr_set->hsize = last_used;

 for (last_used = 0, index = 0; index < pr_set->nsize; index++) {
   if (FD_ISSET(pr_set->narray[index], set)) {
     pr_set->narray[last_used++] = pr_set->narray[index];
   }
 }
 pr_set->nsize = last_used;
}

PR_IMPLEMENT(PRInt32)
PR_Select(PRInt32 unused, PR_fd_set* pr_rd, PR_fd_set* pr_wr, PR_fd_set* pr_ex,
         PRIntervalTime timeout) {
 fd_set rd, wr, ex;
 struct timeval tv, *tvp;
 PRInt32 max, max_fd;
 PRInt32 rv;
 /*
  * For restarting select() if it is interrupted by a Unix signal.
  * We use these variables to figure out how much time has elapsed
  * and how much of the timeout still remains.
  */
 PRIntervalTime start = 0, elapsed, remaining;

 static PRBool unwarned = PR_TRUE;
 if (unwarned) {
   unwarned = _PR_Obsolete("PR_Select", "PR_Poll");
 }

 FD_ZERO(&rd);
 FD_ZERO(&wr);
 FD_ZERO(&ex);

 max_fd = _PR_getset(pr_rd, &rd);
 max_fd = (max = _PR_getset(pr_wr, &wr)) > max_fd ? max : max_fd;
 max_fd = (max = _PR_getset(pr_ex, &ex)) > max_fd ? max : max_fd;

 if (timeout == PR_INTERVAL_NO_TIMEOUT) {
   tvp = NULL;
 } else {
   tv.tv_sec = (PRInt32)PR_IntervalToSeconds(timeout);
   tv.tv_usec = (PRInt32)PR_IntervalToMicroseconds(
       timeout - PR_SecondsToInterval(tv.tv_sec));
   tvp = &tv;
   start = PR_IntervalNow();
 }

retry:
 rv = select(max_fd + 1, (_PRSelectFdSetArg_t)&rd, (_PRSelectFdSetArg_t)&wr,
             (_PRSelectFdSetArg_t)&ex, tvp);

 if (rv == -1 && errno == EINTR) {
   if (timeout == PR_INTERVAL_NO_TIMEOUT) {
     goto retry;
   } else {
     elapsed = (PRIntervalTime)(PR_IntervalNow() - start);
     if (elapsed > timeout) {
       rv = 0; /* timed out */
     } else {
       remaining = timeout - elapsed;
       tv.tv_sec = (PRInt32)PR_IntervalToSeconds(remaining);
       tv.tv_usec = (PRInt32)PR_IntervalToMicroseconds(
           remaining - PR_SecondsToInterval(tv.tv_sec));
       goto retry;
     }
   }
 }

 if (rv > 0) {
   _PR_setset(pr_rd, &rd);
   _PR_setset(pr_wr, &wr);
   _PR_setset(pr_ex, &ex);
 } else if (rv == -1) {
   pt_MapError(_PR_MD_MAP_SELECT_ERROR, errno);
 }
 return rv;
}
#endif /* defined(_PR_PTHREADS) */

#ifdef MOZ_UNICODE
/* ================ UTF16 Interfaces ================================ */
PR_IMPLEMENT(PRFileDesc*)
PR_OpenFileUTF16(const PRUnichar* name, PRIntn flags, PRIntn mode) {
 PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0);
 return NULL;
}

PR_IMPLEMENT(PRStatus) PR_CloseDirUTF16(PRDir* dir) {
 PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0);
 return PR_FAILURE;
}

PR_IMPLEMENT(PRDirUTF16*) PR_OpenDirUTF16(const PRUnichar* name) {
 PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0);
 return NULL;
}

PR_IMPLEMENT(PRDirEntryUTF16*)
PR_ReadDirUTF16(PRDirUTF16* dir, PRDirFlags flags) {
 PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0);
 return NULL;
}

PR_IMPLEMENT(PRStatus)
PR_GetFileInfo64UTF16(const PRUnichar* fn, PRFileInfo64* info) {
 PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0);
 return PR_FAILURE;
}
/* ================ UTF16 Interfaces ================================ */
#endif /* MOZ_UNICODE */

/* ptio.c */