ICU-551.24.tar.gz

[apple/icu.git] / icuSources / common / umutex.h

diff --git a/icuSources/common/umutex.h b/icuSources/common/umutex.h
index ae713bed168159a88204676a1f0cefa8fc378fdb..e0ad0d3c03654d61a023a082548563d8d4c03c61 100644 (file)
--- a/icuSources/common/umutex.h
+++ b/icuSources/common/umutex.h
@@ -1,6 +1,6 @@
 /*
 **********************************************************************
 /*
 **********************************************************************

-*   Copyright (C) 1997-2001, International Business Machines
+*   Copyright (C) 1997-2014, International Business Machines

 *   Corporation and others.  All Rights Reserved.
 **********************************************************************
 *
 *   Corporation and others.  All Rights Reserved.
 **********************************************************************
 *


@@ -19,96 +19,406 @@
 #define UMUTEX_H
 
 #include "unicode/utypes.h"
 #define UMUTEX_H
 
 #include "unicode/utypes.h"

+#include "unicode/uclean.h"
+#include "putilimp.h"

 
 

-/**
- * Mutex data type.
- * @internal
+
+
+// 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>
+
+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.
+
+# define WIN32_LEAN_AND_MEAN
+# 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_GCC_ATOMICS
+/*
+ * gcc atomic ops. These are available on several other compilers as well.

  */
  */

-typedef void *UMTX;

 
 

-/* APP_NO_THREADS is an old symbol. We'll honour it if present. */
-#ifdef APP_NO_THREADS
-# define ICU_USE_THREADS 0
-#endif
+U_NAMESPACE_BEGIN
+typedef int32_t u_atomic_int32_t;
+#define ATOMIC_INT32_T_INITIALIZER(val) val

 
 

-/* Default: use threads. */
-#ifndef ICU_USE_THREADS
-# define ICU_USE_THREADS 1
-#endif
+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 this library which accesses protected data should
- * instantiate a Mutex object while doing so.  Notice that there is
- * only one coarse-grained lock which applies to this entire library,
- * 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 */
+
+
+
+/*************************************************************************************************
+ *
+ *  UInitOnce Definitions.
+ *     These are platform neutral.

  *
  *

- * For example:
+ *************************************************************************************************/
+
+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 (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 (*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 (*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 (*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 (*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
+
+
+
+/*************************************************************************************************

  *
  *

- * void Function(int arg1, int arg2)
- * {
- *   static Object* foo; // Shared read-write object
- *   Mutex mutex;
- *   foo->Method();
- *   // When 'mutex' goes out of scope and gets destroyed here
- *   // the lock is released
- * }
+ *  Mutex Definitions. Platform Dependent, #if platform chain follows.
+ *         TODO:  Add a C++11 version.
+ *                Need to convert all mutex using files to C++ first.

  *
  *

- * Note: Do NOT use the form 'Mutex mutex();' as that merely
- * forward-declares a function returning a Mutex. This is a common
- * mistake which silently slips through the compiler!!  */
+ *************************************************************************************************/
+
+#if defined(U_USER_MUTEX_H)
+// #inlcude "U_USER_MUTEX_H"
+#include U_MUTEX_XSTR(U_USER_MUTEX_H)

 
 

+#elif U_PLATFORM_HAS_WIN32_API

 
 

-/* Lock a mutex. Pass in NULL if you want the (ick) Single Global
-   Mutex. 
- * @param mutex The given mutex to be locked
+/* Windows Definitions.
+ *    Windows comes first in the platform chain.
+ *    Cygwin (and possibly others) have both WIN32 and POSIX APIs. Prefer Win32 in this case.

  */
  */

-U_CAPI void U_EXPORT2 umtx_lock   ( UMTX* mutex ); 

 
 

-/* Unlock a mutex. Pass in NULL if you want the single global
-   mutex. 
- * @param mutex The given mutex to be unlocked
+
+/* 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.

  */
  */

-U_CAPI void U_EXPORT2 umtx_unlock ( UMTX* mutex );

 
 

-/* Initialize a mutex. Use it this way:
-   umtx_init( &aMutex ); 
- * ICU Mutexes, aside from the global mutex, must be explicitly initialized
- * before use.
- * @param mutex The given mutex to be initialized
+# define WIN32_LEAN_AND_MEAN
+# 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.

  */
  */

-U_CAPI void U_EXPORT2 umtx_init   ( UMTX* mutex );
+#define U_MUTEX_INITIALIZER {U_INITONCE_INITIALIZER}

 
 

-/* Destroy a mutex. This will free the resources of a mutex.
-   Use it this way:
-   umtx_destroy( &aMutex ); 
- * @param mutex The given mutex to be destroyed
+struct UConditionVar {
+    HANDLE           fEntryGate;
+    HANDLE           fExitGate;
+    int32_t          fWaitCount;
+};
+
+#define U_CONDITION_INITIALIZER {NULL, NULL, 0}
+    
+
+
+#elif U_PLATFORM_IMPLEMENTS_POSIX
+
+/*
+ *  POSIX platform

  */
  */

-U_CAPI void U_EXPORT2 umtx_destroy( UMTX *mutex );
-
-/* Is a mutex initialized? 
-   Use it this way:
-      umtx_isInitialized( &aMutex ); 
-   This function is not normally needed.  It is more efficient to 
-   unconditionally call umtx_init(&aMutex) than it is to check first. 
- * @param mutex The given mutex to be tested
-*/
-U_CAPI UBool U_EXPORT2 umtx_isInitialized( UMTX *mutex );
+
+#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

 
 /*
 
 /*

- * Atomic Increment and Decrement of an int32_t value.
+ *  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.

  *
  *

- * 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.
+ ************************************************************************************/
+
+/* 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 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_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);

 
 

-#endif /*_CMUTEX*/
-/*eof*/
+/*
+ * 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*/