// © 2016 and later: Unicode, Inc. and others.

// License & terms of use: http://www.unicode.org/copyright.html

/*

******************************************************************************

* Copyright (C) 2001-2014, International Business Machines

*                Corporation and others. All Rights Reserved.

******************************************************************************

*   file name:  ucln_cmn.cpp

*   encoding:   UTF-8

*   tab size:   8 (not used)

*   indentation:4

*

*   created on: 2001July05

*   created by: George Rhoten

*/

#include "unicode/utypes.h"

#include "unicode/uclean.h"

#include "cmemory.h"

#include "mutex.h"

#include "uassert.h"

#include "ucln.h"

#include "ucln_cmn.h"

#include "utracimp.h"

#include "umutex.h"

/**  Auto-client for UCLN_COMMON **/

#define UCLN_TYPE_IS_COMMON

#include "ucln_imp.h"

static cleanupFunc *gCommonCleanupFunctions[UCLN_COMMON_COUNT];

static cleanupFunc *gLibCleanupFunctions[UCLN_COMMON];

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

 The cleanup order is important in this function.

 Please be sure that you have read ucln.h

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

U_CAPI void U_EXPORT2

u_cleanup(void)

{

    UTRACE_ENTRY_OC(UTRACE_U_CLEANUP);

    icu::umtx_lock(NULL);     /* Force a memory barrier, so that we are sure to see   */

    icu::umtx_unlock(NULL);   /*   all state left around by any other threads.        */

    ucln_lib_cleanup();

    cmemory_cleanup();       /* undo any heap functions set by u_setMemoryFunctions(). */

    UTRACE_EXIT();           /* Must be before utrace_cleanup(), which turns off tracing. */

/*#if U_ENABLE_TRACING*/

    utrace_cleanup();

/*#endif*/

}

U_CAPI void U_EXPORT2 ucln_cleanupOne(ECleanupLibraryType libType) 

{

    if (gLibCleanupFunctions[libType])

    {

        gLibCleanupFunctions[libType]();

        gLibCleanupFunctions[libType] = NULL;

    }

}

U_CFUNC void

ucln_common_registerCleanup(ECleanupCommonType type,

                            cleanupFunc *func)

{

    // Thread safety messiness: From ticket 10295, calls to registerCleanup() may occur

    // concurrently. Although such cases should be storing the same value, they raise errors

    // from the thread sanity checker. Doing the store within a mutex avoids those.

    // BUT that can trigger a recursive entry into std::call_once() in umutex.cpp when this code,

    // running from the call_once function, tries to grab the ICU global mutex, which

    // re-enters the mutex init path. So, work-around by special casing UCLN_COMMON_MUTEX, not

    // using the ICU global mutex for it.

    //

    // No other point in ICU uses std::call_once().

    U_ASSERT(UCLN_COMMON_START < type && type < UCLN_COMMON_COUNT);

    if (type == UCLN_COMMON_MUTEX) {

        gCommonCleanupFunctions[type] = func;

    } else if (UCLN_COMMON_START < type && type < UCLN_COMMON_COUNT)  {

        icu::Mutex m;     // See ticket 10295 for discussion.

        gCommonCleanupFunctions[type] = func;

    }

#if !UCLN_NO_AUTO_CLEANUP && (defined(UCLN_AUTO_ATEXIT) || defined(UCLN_AUTO_LOCAL))

    ucln_registerAutomaticCleanup();

#endif

}

// Note: ucln_registerCleanup() is called with the ICU global mutex locked.

//       Be aware if adding anything to the function.

//       See ticket 10295 for discussion.

U_CAPI void U_EXPORT2

ucln_registerCleanup(ECleanupLibraryType type,

                     cleanupFunc *func)

{

    U_ASSERT(UCLN_START < type && type < UCLN_COMMON);

    if (UCLN_START < type && type < UCLN_COMMON)

    {

        gLibCleanupFunctions[type] = func;

    }

}

U_CFUNC UBool ucln_lib_cleanup(void) {

    int32_t libType = UCLN_START;

    int32_t commonFunc = UCLN_COMMON_START;

    for (libType++; libType<UCLN_COMMON; libType++) {

        ucln_cleanupOne(static_cast<ECleanupLibraryType>(libType));

    }

    for (commonFunc++; commonFunc<UCLN_COMMON_COUNT; commonFunc++) {

        if (gCommonCleanupFunctions[commonFunc])

        {

            gCommonCleanupFunctions[commonFunc]();

            gCommonCleanupFunctions[commonFunc] = NULL;

        }

    }

#if !UCLN_NO_AUTO_CLEANUP && (defined(UCLN_AUTO_ATEXIT) || defined(UCLN_AUTO_LOCAL))

    ucln_unRegisterAutomaticCleanup();

#endif

    return TRUE;

}