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
31static cleanupFunc *gCommonCleanupFunctions[UCLN_COMMON_COUNT];
32static 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 ************************************************/
39U_CAPI void U_EXPORT2
40u_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
55U_CAPI void U_EXPORT2 ucln_cleanupOne(ECleanupLibraryType libType)
56{
57 if (gLibCleanupFunctions[libType])
58 {
59 gLibCleanupFunctions[libType]();
60 gLibCleanupFunctions[libType] = nullptr;
61 }
62}
63
64U_CFUNC void
65ucln_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
94U_CAPI void U_EXPORT2
95ucln_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
105U_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}
125