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pprmwait.h (4337B)

      1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* This Source Code Form is subject to the terms of the Mozilla Public
      3 * License, v. 2.0. If a copy of the MPL was not distributed with this
      4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      5 
      6 #if defined(_PPRMWAIT_H)
      7 #else
      8 #define _PPRMWAIT_H
      9 
     10 #include "prlock.h"
     11 #include "prcvar.h"
     12 #include "prclist.h"
     13 #include "prthread.h"
     14 
     15 #define MAX_POLLING_INTERVAL 100
     16 #define _PR_POLL_COUNT_FUDGE 64
     17 #define _PR_DEFAULT_HASH_LENGTH 59
     18 
     19 /*
     20 * Our hash table resolves collisions by open addressing with
     21 * double hashing.  See Cormen, Leiserson, and Rivest,
     22 * Introduction to Algorithms, p. 232, The MIT Press, 1990.
     23 */
     24 
     25 #define _MW_HASH(a, m) ((((PRUptrdiff)(a) >> 4) ^ ((PRUptrdiff)(a) >> 10)) % (m))
     26 #define _MW_HASH2(a, m) (1 + ((((PRUptrdiff)(a) >> 4) ^ ((PRUptrdiff)(a) >> 10)) % (m - 2)))
     27 #define _MW_ABORTED(_rv) \
     28    ((PR_FAILURE == (_rv)) && (PR_PENDING_INTERRUPT_ERROR == PR_GetError()))
     29 
     30 typedef enum {_prmw_success, _prmw_rehash, _prmw_error} _PR_HashStory;
     31 
     32 typedef struct _PRWaiterHash
     33 {
     34    PRUint16 count;             /* current number in hash table */
     35    PRUint16 length;            /* current size of the hash table */
     36    PRRecvWait *recv_wait;      /* hash table of receive wait objects */
     37 } _PRWaiterHash;
     38 
     39 typedef enum {_prmw_running, _prmw_stopping, _prmw_stopped} PRMWGroupState;
     40 
     41 struct PRWaitGroup
     42 {
     43    PRCList group_link;         /* all groups are linked to each other */
     44    PRCList io_ready;           /* list of I/O requests that are ready */
     45    PRMWGroupState state;       /* state of this group (so we can shut down) */
     46 
     47    PRLock *ml;                 /* lock for synchronizing this wait group */
     48    PRCondVar *io_taken;        /* calling threads notify when they take I/O */
     49    PRCondVar *io_complete;     /* calling threads wait here for completions */
     50    PRCondVar *new_business;    /* polling thread waits here more work */
     51    PRCondVar *mw_manage;       /* used to manage group lists */
     52    PRThread* poller;           /* thread that's actually doing the poll() */
     53    PRUint16 waiting_threads;   /* number of threads waiting for recv */
     54    PRUint16 polling_count;     /* number of elements in the polling list */
     55    PRUint32 p_timestamp;       /* pseudo-time group had element removed */
     56    PRPollDesc *polling_list;   /* list poller builds for polling */
     57    PRIntervalTime last_poll;   /* last time we polled */
     58    _PRWaiterHash *waiter;      /* pointer to hash table of wait receive objects */
     59 
     60 #ifdef WINNT
     61    /*
     62     * On NT, idle threads are responsible for getting completed i/o.
     63     * They need to add completed i/o to the io_ready list.  Since
     64     * idle threads cannot use nspr locks, we have to use an md lock
     65     * to protect the io_ready list.
     66     */
     67    _MDLock mdlock;             /* protect io_ready, waiter, and wait_list */
     68    PRCList wait_list;          /* used in place of io_complete.  reuse
     69                                 * waitQLinks in the PRThread structure. */
     70 #endif /* WINNT */
     71 };
     72 
     73 /**********************************************************************
     74 ***********************************************************************
     75 ******************** Wait group enumerations **************************
     76 ***********************************************************************
     77 **********************************************************************/
     78 typedef struct _PRGlobalState
     79 {
     80    PRCList group_list;         /* master of the group list */
     81    PRWaitGroup *group;         /* the default (NULL) group */
     82 } _PRGlobalState;
     83 
     84 #ifdef WINNT
     85 extern PRStatus NT_HashRemoveInternal(PRWaitGroup *group, PRFileDesc *fd);
     86 #endif
     87 
     88 typedef enum {_PR_ENUM_UNSEALED=0, _PR_ENUM_SEALED=0x0eadface} _PREnumSeal;
     89 
     90 struct PRMWaitEnumerator
     91 {
     92    PRWaitGroup *group;       /* group this enumerator is bound to */
     93    PRThread *thread;               /* thread in midst of an enumeration */
     94    _PREnumSeal seal;               /* trying to detect deleted objects */
     95    PRUint32 p_timestamp;           /* when enumeration was (re)started */
     96    PRRecvWait **waiter;            /* pointer into hash table */
     97    PRUintn index;                  /* position in hash table */
     98    void *pad[4];                   /* some room to grow */
     99 };
    100 
    101 #endif /* defined(_PPRMWAIT_H) */
    102 
    103 /* pprmwait.h */