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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
**********************************************************************
* Copyright (C) 1997-2015, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
*
* File UMUTEX.H
*
* Modification History:
*
* Date Name Description
* 04/02/97 aliu Creation.
* 04/07/99 srl rewrite - C interface, multiple mutices
* 05/13/99 stephen Changed to umutex (from cmutex)
******************************************************************************
*/
#ifndef UMUTEX_H
#define UMUTEX_H
#include "unicode/utypes.h"
#include "unicode/uclean.h"
#include "putilimp.h"
// Forward Declarations. UMutex is not in the ICU namespace (yet) because
// there are some remaining references from plain C.
struct UMutex;
struct UConditionVar;
U_NAMESPACE_BEGIN
struct UInitOnce;
U_NAMESPACE_END
// Stringify macros, to allow #include of user supplied atomic & mutex files.
#define U_MUTEX_STR(s) #s
#define U_MUTEX_XSTR(s) U_MUTEX_STR(s)
/****************************************************************************
*
* Low Level Atomic Operations.
* Compiler dependent. Not operating system dependent.
*
****************************************************************************/
#if defined (U_USER_ATOMICS_H)
#include U_MUTEX_XSTR(U_USER_ATOMICS_H)
#elif U_HAVE_STD_ATOMICS
// C++11 atomics are available.
#include <atomic>
// Export an explicit template instantiation of std::atomic<int32_t>.
// When building DLLs for Windows this is required as it is used as a data member of the exported SharedObject class.
// See digitlst.h, pluralaffix.h, datefmt.h, and others for similar examples.
#if U_PF_WINDOWS <= U_PLATFORM && U_PLATFORM <= U_PF_CYGWIN && !defined(U_IN_DOXYGEN)
#if defined(__clang__) && __has_warning("-Winstantiation-after-specialization")
// Suppress the warning that the explicit instantiation after explicit specialization has no effect.
#pragma clang diagnostic ignored "-Winstantiation-after-specialization"
#endif
template <> struct U_COMMON_API std::atomic<int32_t>;
#endif
U_NAMESPACE_BEGIN
typedef std::atomic<int32_t> u_atomic_int32_t;
#define ATOMIC_INT32_T_INITIALIZER(val) ATOMIC_VAR_INIT(val)
inline int32_t umtx_loadAcquire(u_atomic_int32_t &var) {
return var.load(std::memory_order_acquire);
}
inline void umtx_storeRelease(u_atomic_int32_t &var, int32_t val) {
var.store(val, std::memory_order_release);
}
inline int32_t umtx_atomic_inc(u_atomic_int32_t *var) {
return var->fetch_add(1) + 1;
}
inline int32_t umtx_atomic_dec(u_atomic_int32_t *var) {
return var->fetch_sub(1) - 1;
}
U_NAMESPACE_END
#elif U_PLATFORM_HAS_WIN32_API
// MSVC compiler. Reads and writes of volatile variables have
// acquire and release memory semantics, respectively.
// This is a Microsoft extension, not standard C++ behavior.
//
// Update: can't use this because of MinGW, built with gcc.
// Original plan was to use gcc atomics for MinGW, but they
// aren't supported, so we fold MinGW into this path.
#ifndef WIN32_LEAN_AND_MEAN
# define WIN32_LEAN_AND_MEAN
#endif
# define VC_EXTRALEAN
# define NOUSER
# define NOSERVICE
# define NOIME
# define NOMCX
# ifndef NOMINMAX
# define NOMINMAX
# endif
# include <windows.h>
U_NAMESPACE_BEGIN
typedef volatile LONG u_atomic_int32_t;
#define ATOMIC_INT32_T_INITIALIZER(val) val
inline int32_t umtx_loadAcquire(u_atomic_int32_t &var) {
return InterlockedCompareExchange(&var, 0, 0);
}
inline void umtx_storeRelease(u_atomic_int32_t &var, int32_t val) {
InterlockedExchange(&var, val);
}
inline int32_t umtx_atomic_inc(u_atomic_int32_t *var) {
return InterlockedIncrement(var);
}
inline int32_t umtx_atomic_dec(u_atomic_int32_t *var) {
return InterlockedDecrement(var);
}
U_NAMESPACE_END
#elif U_HAVE_CLANG_ATOMICS
/*
* Clang __c11 atomic built-ins
*/
U_NAMESPACE_BEGIN
typedef _Atomic(int32_t) u_atomic_int32_t;
#define ATOMIC_INT32_T_INITIALIZER(val) val
inline int32_t umtx_loadAcquire(u_atomic_int32_t &var) {
return __c11_atomic_load(&var, __ATOMIC_ACQUIRE);
}
inline void umtx_storeRelease(u_atomic_int32_t &var, int32_t val) {
return __c11_atomic_store(&var, val, __ATOMIC_RELEASE);
}
inline int32_t umtx_atomic_inc(u_atomic_int32_t *var) {
return __c11_atomic_fetch_add(var, 1, __ATOMIC_SEQ_CST) + 1;
}
inline int32_t umtx_atomic_dec(u_atomic_int32_t *var) {
return __c11_atomic_fetch_sub(var, 1, __ATOMIC_SEQ_CST) - 1;
}
U_NAMESPACE_END
#elif U_HAVE_GCC_ATOMICS
/*
* gcc atomic ops. These are available on several other compilers as well.
*/
U_NAMESPACE_BEGIN
typedef int32_t u_atomic_int32_t;
#define ATOMIC_INT32_T_INITIALIZER(val) val
inline int32_t umtx_loadAcquire(u_atomic_int32_t &var) {
int32_t val = var;
__sync_synchronize();
return val;
}
inline void umtx_storeRelease(u_atomic_int32_t &var, int32_t val) {
__sync_synchronize();
var = val;
}
inline int32_t umtx_atomic_inc(u_atomic_int32_t *p) {
return __sync_add_and_fetch(p, 1);
}
inline int32_t umtx_atomic_dec(u_atomic_int32_t *p) {
return __sync_sub_and_fetch(p, 1);
}
U_NAMESPACE_END
#else
/*
* Unknown Platform. Use out-of-line functions, which in turn use mutexes.
* Slow but correct.
*/
#define U_NO_PLATFORM_ATOMICS
U_NAMESPACE_BEGIN
typedef int32_t u_atomic_int32_t;
#define ATOMIC_INT32_T_INITIALIZER(val) val
U_COMMON_API int32_t U_EXPORT2
umtx_loadAcquire(u_atomic_int32_t &var);
U_COMMON_API void U_EXPORT2
umtx_storeRelease(u_atomic_int32_t &var, int32_t val);
U_COMMON_API int32_t U_EXPORT2
umtx_atomic_inc(u_atomic_int32_t *p);
U_COMMON_API int32_t U_EXPORT2
umtx_atomic_dec(u_atomic_int32_t *p);
U_NAMESPACE_END
#endif /* Low Level Atomic Ops Platform Chain */
/*************************************************************************************************
*
* UInitOnce Definitions.
* These are platform neutral.
*
*************************************************************************************************/
U_NAMESPACE_BEGIN
struct UInitOnce {
u_atomic_int32_t fState;
UErrorCode fErrCode;
void reset() {fState = 0;};
UBool isReset() {return umtx_loadAcquire(fState) == 0;};
// Note: isReset() is used by service registration code.
// Thread safety of this usage needs review.
};
#define U_INITONCE_INITIALIZER {ATOMIC_INT32_T_INITIALIZER(0), U_ZERO_ERROR}
U_COMMON_API UBool U_EXPORT2 umtx_initImplPreInit(UInitOnce &);
U_COMMON_API void U_EXPORT2 umtx_initImplPostInit(UInitOnce &);
template<class T> void umtx_initOnce(UInitOnce &uio, T *obj, void (U_CALLCONV T::*fp)()) {
if (umtx_loadAcquire(uio.fState) == 2) {
return;
}
if (umtx_initImplPreInit(uio)) {
(obj->*fp)();
umtx_initImplPostInit(uio);
}
}
// umtx_initOnce variant for plain functions, or static class functions.
// No context parameter.
inline void umtx_initOnce(UInitOnce &uio, void (U_CALLCONV *fp)()) {
if (umtx_loadAcquire(uio.fState) == 2) {
return;
}
if (umtx_initImplPreInit(uio)) {
(*fp)();
umtx_initImplPostInit(uio);
}
}
// umtx_initOnce variant for plain functions, or static class functions.
// With ErrorCode, No context parameter.
inline void umtx_initOnce(UInitOnce &uio, void (U_CALLCONV *fp)(UErrorCode &), UErrorCode &errCode) {
if (U_FAILURE(errCode)) {
return;
}
if (umtx_loadAcquire(uio.fState) != 2 && umtx_initImplPreInit(uio)) {
// We run the initialization.
(*fp)(errCode);
uio.fErrCode = errCode;
umtx_initImplPostInit(uio);
} else {
// Someone else already ran the initialization.
if (U_FAILURE(uio.fErrCode)) {
errCode = uio.fErrCode;
}
}
}
// umtx_initOnce variant for plain functions, or static class functions,
// with a context parameter.
template<class T> void umtx_initOnce(UInitOnce &uio, void (U_CALLCONV *fp)(T), T context) {
if (umtx_loadAcquire(uio.fState) == 2) {
return;
}
if (umtx_initImplPreInit(uio)) {
(*fp)(context);
umtx_initImplPostInit(uio);
}
}
// umtx_initOnce variant for plain functions, or static class functions,
// with a context parameter and an error code.
template<class T> void umtx_initOnce(UInitOnce &uio, void (U_CALLCONV *fp)(T, UErrorCode &), T context, UErrorCode &errCode) {
if (U_FAILURE(errCode)) {
return;
}
if (umtx_loadAcquire(uio.fState) != 2 && umtx_initImplPreInit(uio)) {
// We run the initialization.
(*fp)(context, errCode);
uio.fErrCode = errCode;
umtx_initImplPostInit(uio);
} else {
// Someone else already ran the initialization.
if (U_FAILURE(uio.fErrCode)) {
errCode = uio.fErrCode;
}
}
}
U_NAMESPACE_END
/*************************************************************************************************
*
* Mutex Definitions. Platform Dependent, #if platform chain follows.
* TODO: Add a C++11 version.
* Need to convert all mutex using files to C++ first.
*
*************************************************************************************************/
#if defined(U_USER_MUTEX_H)
// #include "U_USER_MUTEX_H"
#include U_MUTEX_XSTR(U_USER_MUTEX_H)
#elif U_PLATFORM_USES_ONLY_WIN32_API
/* For CRITICAL_SECTION */
/*
* Note: there is an earlier include of windows.h in this file, but it is in
* different conditionals.
* This one is needed if we are using C++11 for atomic ops, but
* win32 APIs for Critical Sections.
*/
#ifndef WIN32_LEAN_AND_MEAN
# define WIN32_LEAN_AND_MEAN
#endif
# define VC_EXTRALEAN
# define NOUSER
# define NOSERVICE
# define NOIME
# define NOMCX
# ifndef NOMINMAX
# define NOMINMAX
# endif
# include <windows.h>
typedef struct UMutex {
icu::UInitOnce fInitOnce;
CRITICAL_SECTION fCS;
} UMutex;
/* Initializer for a static UMUTEX. Deliberately contains no value for the
* CRITICAL_SECTION.
*/
#define U_MUTEX_INITIALIZER {U_INITONCE_INITIALIZER}
struct UConditionVar {
HANDLE fEntryGate;
HANDLE fExitGate;
int32_t fWaitCount;
};
#define U_CONDITION_INITIALIZER {NULL, NULL, 0}
#elif U_PLATFORM_IMPLEMENTS_POSIX
/*
* POSIX platform
*/
#include <pthread.h>
struct UMutex {
pthread_mutex_t fMutex;
};
typedef struct UMutex UMutex;
#define U_MUTEX_INITIALIZER {PTHREAD_MUTEX_INITIALIZER}
struct UConditionVar {
pthread_cond_t fCondition;
};
#define U_CONDITION_INITIALIZER {PTHREAD_COND_INITIALIZER}
#else
/*
* Unknown platform type.
* This is an error condition. ICU requires mutexes.
*/
#error Unknown Platform.
#endif
/**************************************************************************************
*
* Mutex Implementation function declarations.
* Declarations are platform neutral.
* Implementations, in umutex.cpp, are platform specific.
*
************************************************************************************/
/* Lock a mutex.
* @param mutex The given mutex to be locked. Pass NULL to specify
* the global ICU mutex. Recursive locks are an error
* and may cause a deadlock on some platforms.
*/
U_INTERNAL void U_EXPORT2 umtx_lock(UMutex* mutex);
/* Unlock a mutex.
* @param mutex The given mutex to be unlocked. Pass NULL to specify
* the global ICU mutex.
*/
U_INTERNAL void U_EXPORT2 umtx_unlock (UMutex* mutex);
/*
* Wait on a condition variable.
* The calling thread will unlock the mutex and wait on the condition variable.
* The mutex must be locked by the calling thread when invoking this function.
*
* @param cond the condition variable to wait on.
* @param mutex the associated mutex.
*/
U_INTERNAL void U_EXPORT2 umtx_condWait(UConditionVar *cond, UMutex *mutex);
/*
* Broadcast wakeup of all threads waiting on a Condition.
* The associated mutex must be locked by the calling thread when calling
* this function; this is a temporary ICU restriction.
*
* @param cond the condition variable.
*/
U_INTERNAL void U_EXPORT2 umtx_condBroadcast(UConditionVar *cond);
/*
* Signal a condition variable, waking up one waiting thread.
* CAUTION: Do not use. Place holder only. Not implemented for Windows.
*/
U_INTERNAL void U_EXPORT2 umtx_condSignal(UConditionVar *cond);
#endif /* UMUTEX_H */
/*eof*/