icuSources/common/ucln_cmn.cpp

   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(void)
  41 {
  42     UTRACE_ENTRY_OC(UTRACE_U_CLEANUP);
  43     icu::umtx_lock(NULL);     /* Force a memory barrier, so that we are sure to see   */
  44     icu::umtx_unlock(NULL);   /*   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] = NULL;
  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(void) {
 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] = NULL;
 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 }