+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
/*
**********************************************************************
-* Copyright (C) 1997-2004, International Business Machines
+* Copyright (C) 1997-2015, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
*
#define UMUTEX_H
#include "unicode/utypes.h"
-#include "unicode/uclean.h"
+#include "unicode/uclean.h"
+#include "putilimp.h"
-/* APP_NO_THREADS is an old symbol. We'll honour it if present. */
-#ifdef APP_NO_THREADS
-# define ICU_USE_THREADS 0
-#endif
-/* ICU_USE_THREADS
+// 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)
+
+/****************************************************************************
*
- * Allows thread support (use of mutexes) to be compiled out of ICU.
- * Default: use threads.
- * Even with thread support compiled out, applications may override the
- * (empty) mutex implementation with the u_setMutexFunctions() functions.
- */
-#ifndef ICU_USE_THREADS
-# define ICU_USE_THREADS 1
+ * 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>
+
+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);
+}
+
-/**
- * \def UMTX_CHECK
- * Encapsulates a safe check for an expression (usually a condition)
- * for lazy variable inititialization.
- * On CPUs with weak memory models, this must use memory fence instructions
- * or mutexes.
- * @internal
+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
*/
-#if UMTX_STRONG_MEMORY_MODEL
-#define UMTX_CHECK(pMutex, expression, result) \
- (result)=(expression);
+U_NAMESPACE_BEGIN
+typedef _Atomic(int32_t) u_atomic_int32_t;
+#define ATOMIC_INT32_T_INITIALIZER(val) val
-#else
+inline int32_t umtx_loadAcquire(u_atomic_int32_t &var) {
+ return __c11_atomic_load(&var, __ATOMIC_ACQUIRE);
+}
-#define UMTX_CHECK(pMutex, expression, result) \
- umtx_lock(pMutex); \
- (result)=(expression); \
- umtx_unlock(pMutex);
+inline void umtx_storeRelease(u_atomic_int32_t &var, int32_t val) {
+ return __c11_atomic_store(&var, val, __ATOMIC_RELEASE);
+}
-#endif
+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
/*
- * Code within ICU that accesses shared static or global data should
- * instantiate a Mutex object while doing so. The unnamed global mutex
- * is used throughout ICU, so keep locking short and sweet.
+ * 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 Platfrom Chain */
+
+
+
+/*************************************************************************************************
*
- * For example:
+ * UInitOnce Definitions.
+ * These are platform neutral.
*
- * void Function(int arg1, int arg2)
- * {
- * static Object* foo; // Shared read-write object
- * umtx_lock(NULL); // Lock the ICU global mutex
- * foo->Method();
- * umtx_unlock(NULL);
- * }
+ *************************************************************************************************/
+
+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.
*
- * an alternative C++ mutex API is defined in the file common/mutex.h
+ *************************************************************************************************/
+
+#if defined(U_USER_MUTEX_H)
+// #inlcude "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}
+
+
-/* Lock a mutex.
+#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
+
+/*
+ * Unknow platform type.
+ * This is an error condition. ICU requires mutexes.
+ */
+
+#error Unknown Platform.
+
+#endif
+
+
+
+/**************************************************************************************
+ *
+ * Mutex Implementation function declaratations.
+ * 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_CAPI void U_EXPORT2 umtx_lock ( UMTX* mutex );
+U_INTERNAL void U_EXPORT2 umtx_lock(UMutex* mutex);
-/* Unlock a mutex. Pass in NULL if you want the single global
- mutex.
+/* Unlock a mutex.
* @param mutex The given mutex to be unlocked. Pass NULL to specify
* the global ICU mutex.
*/
-U_CAPI void U_EXPORT2 umtx_unlock ( UMTX* mutex );
-
-/* Initialize a mutex. Use it this way:
- umtx_init( &aMutex );
- * ICU Mutexes do not need explicit initialization before use. Use of this
- * function is not necessary.
- * Initialization of an already initialized mutex has no effect, and is safe to do.
- * Initialization of mutexes is thread safe. Two threads can concurrently
- * initialize the same mutex without causing problems.
- * @param mutex The given mutex to be initialized
- */
-U_CAPI void U_EXPORT2 umtx_init ( UMTX* mutex );
-
-/* Destroy a mutex. This will free the resources of a mutex.
- * Use it this way:
- * umtx_destroy( &aMutex );
- * Destroying an already destroyed mutex has no effect, and causes no problems.
- * This function is not thread safe. Two threads must not attempt to concurrently
- * destroy the same mutex.
- * @param mutex The given mutex to be destroyed.
- */
-U_CAPI void U_EXPORT2 umtx_destroy( UMTX *mutex );
-
-
+U_INTERNAL void U_EXPORT2 umtx_unlock (UMutex* mutex);
/*
- * Atomic Increment and Decrement of an int32_t value.
+ * 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.
*
- * Return Values:
- * If the result of the operation is zero, the return zero.
- * If the result of the operation is not zero, the sign of returned value
- * is the same as the sign of the result, but the returned value itself may
- * be different from the result of the operation.
+ * @param cond the condition variable to wait on.
+ * @param mutex the associated mutex.
*/
-U_CAPI int32_t U_EXPORT2 umtx_atomic_inc(int32_t *);
-U_CAPI int32_t U_EXPORT2 umtx_atomic_dec(int32_t *);
+U_INTERNAL void U_EXPORT2 umtx_condWait(UConditionVar *cond, UMutex *mutex);
-#endif /*_CMUTEX*/
-/*eof*/
+/*
+ * 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*/
projects / apple / icu.git / blobdiff