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ucln_cmn.cpp (4224B)

      1 // © 2016 and later: Unicode, Inc. and others.
      2 // License & terms of use: http://www.unicode.org/copyright.html
      3 /*
      4 ******************************************************************************
      5 * Copyright (C) 2001-2014, International Business Machines
      6 *                Corporation and others. All Rights Reserved.
      7 ******************************************************************************
      8 *   file name:  ucln_cmn.cpp
      9 *   encoding:   UTF-8
     10 *   tab size:   8 (not used)
     11 *   indentation:4
     12 *
     13 *   created on: 2001July05
     14 *   created by: George Rhoten
     15 */
     16 
     17 #include "unicode/utypes.h"
     18 #include "unicode/uclean.h"
     19 #include "cmemory.h"
     20 #include "mutex.h"
     21 #include "uassert.h"
     22 #include "ucln.h"
     23 #include "ucln_cmn.h"
     24 #include "utracimp.h"
     25 #include "umutex.h"
     26 
     27 /**  Auto-client for UCLN_COMMON **/
     28 #define UCLN_TYPE_IS_COMMON
     29 #include "ucln_imp.h"
     30 
     31 static cleanupFunc *gCommonCleanupFunctions[UCLN_COMMON_COUNT];
     32 static cleanupFunc *gLibCleanupFunctions[UCLN_COMMON];
     33 
     34 
     35 /************************************************
     36 The cleanup order is important in this function.
     37 Please be sure that you have read ucln.h
     38 ************************************************/
     39 U_CAPI void U_EXPORT2
     40 u_cleanup()
     41 {
     42    UTRACE_ENTRY_OC(UTRACE_U_CLEANUP);
     43    icu::umtx_lock(nullptr);     /* Force a memory barrier, so that we are sure to see   */
     44    icu::umtx_unlock(nullptr);   /*   all state left around by any other threads.        */
     45 
     46    ucln_lib_cleanup();
     47 
     48    cmemory_cleanup();       /* undo any heap functions set by u_setMemoryFunctions(). */
     49    UTRACE_EXIT();           /* Must be before utrace_cleanup(), which turns off tracing. */
     50 /*#if U_ENABLE_TRACING*/
     51    utrace_cleanup();
     52 /*#endif*/
     53 }
     54 
     55 U_CAPI void U_EXPORT2 ucln_cleanupOne(ECleanupLibraryType libType) 
     56 {
     57    if (gLibCleanupFunctions[libType])
     58    {
     59        gLibCleanupFunctions[libType]();
     60        gLibCleanupFunctions[libType] = nullptr;
     61    }
     62 }
     63 
     64 U_CFUNC void
     65 ucln_common_registerCleanup(ECleanupCommonType type,
     66                            cleanupFunc *func)
     67 {
     68    // Thread safety messiness: From ticket 10295, calls to registerCleanup() may occur
     69    // concurrently. Although such cases should be storing the same value, they raise errors
     70    // from the thread sanity checker. Doing the store within a mutex avoids those.
     71    // BUT that can trigger a recursive entry into std::call_once() in umutex.cpp when this code,
     72    // running from the call_once function, tries to grab the ICU global mutex, which
     73    // re-enters the mutex init path. So, work-around by special casing UCLN_COMMON_MUTEX, not
     74    // using the ICU global mutex for it.
     75    //
     76    // No other point in ICU uses std::call_once().
     77 
     78    U_ASSERT(UCLN_COMMON_START < type && type < UCLN_COMMON_COUNT);
     79    if (type == UCLN_COMMON_MUTEX) {
     80        gCommonCleanupFunctions[type] = func;
     81    } else if (UCLN_COMMON_START < type && type < UCLN_COMMON_COUNT)  {
     82        icu::Mutex m;     // See ticket 10295 for discussion.
     83        gCommonCleanupFunctions[type] = func;
     84    }
     85 #if !UCLN_NO_AUTO_CLEANUP && (defined(UCLN_AUTO_ATEXIT) || defined(UCLN_AUTO_LOCAL))
     86    ucln_registerAutomaticCleanup();
     87 #endif
     88 }
     89 
     90 // Note: ucln_registerCleanup() is called with the ICU global mutex locked.
     91 //       Be aware if adding anything to the function.
     92 //       See ticket 10295 for discussion.
     93 
     94 U_CAPI void U_EXPORT2
     95 ucln_registerCleanup(ECleanupLibraryType type,
     96                     cleanupFunc *func)
     97 {
     98    U_ASSERT(UCLN_START < type && type < UCLN_COMMON);
     99    if (UCLN_START < type && type < UCLN_COMMON)
    100    {
    101        gLibCleanupFunctions[type] = func;
    102    }
    103 }
    104 
    105 U_CFUNC UBool ucln_lib_cleanup() {
    106    int32_t libType = UCLN_START;
    107    int32_t commonFunc = UCLN_COMMON_START;
    108 
    109    for (libType++; libType<UCLN_COMMON; libType++) {
    110        ucln_cleanupOne(static_cast<ECleanupLibraryType>(libType));
    111    }
    112 
    113    for (commonFunc++; commonFunc<UCLN_COMMON_COUNT; commonFunc++) {
    114        if (gCommonCleanupFunctions[commonFunc])
    115        {
    116            gCommonCleanupFunctions[commonFunc]();
    117            gCommonCleanupFunctions[commonFunc] = nullptr;
    118        }
    119    }
    120 #if !UCLN_NO_AUTO_CLEANUP && (defined(UCLN_AUTO_ATEXIT) || defined(UCLN_AUTO_LOCAL))
    121    ucln_unRegisterAutomaticCleanup();
    122 #endif
    123    return true;
    124 }