X-Git-Url: https://git.saurik.com/apple/icu.git/blobdiff_plain/57a6839dcb3bba09e8228b822b290604668416fe..cecc3f9394f261e71def48cf396d137687dbd0a7:/icuSources/common/umutex.cpp

diff --git a/icuSources/common/umutex.cpp b/icuSources/common/umutex.cpp
index 8f552089..29dbc90e 100644
--- a/icuSources/common/umutex.cpp
+++ b/icuSources/common/umutex.cpp
@@ -1,7 +1,9 @@
+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
 /*
 ******************************************************************************
 *
-*   Copyright (C) 1997-2013, International Business Machines
+*   Copyright (C) 1997-2016, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 ******************************************************************************
@@ -23,7 +25,6 @@
 #include "unicode/utypes.h"
 #include "uassert.h"
 #include "cmemory.h"
-#include "ucln_cmn.h"
 
 
 // The ICU global mutex. Used when ICU implementation code passes NULL for the mutex pointer.
@@ -38,16 +39,7 @@ static UMutex   globalMutex = U_MUTEX_INITIALIZER;
 // Build time user mutex hook: #include "U_USER_MUTEX_CPP"
 #include U_MUTEX_XSTR(U_USER_MUTEX_CPP)
 
-#elif U_PLATFORM_HAS_WIN32_API
-
-//-------------------------------------------------------------------------------------------
-//
-//    Windows Specific Definitions
-//
-//        Note: Cygwin (and possibly others) have both WIN32 and POSIX.
-//              Prefer Win32 in these cases.  (Win32 comes ahead in the #if chain)
-//
-//-------------------------------------------------------------------------------------------
+#elif U_PLATFORM_USES_ONLY_WIN32_API
 
 #if defined U_NO_PLATFORM_ATOMICS
 #error ICU on Win32 requires support for low level atomic operations.
@@ -69,10 +61,8 @@ U_NAMESPACE_BEGIN
 U_COMMON_API UBool U_EXPORT2 umtx_initImplPreInit(UInitOnce &uio) {
     for (;;) {
         int32_t previousState = InterlockedCompareExchange(
-#if (U_PLATFORM == U_PF_MINGW) || (U_PLATFORM == U_PF_CYGWIN)
-           (LONG volatile *) // this is the type given in the API doc for this function.
-#endif
-            &uio.fState,  //  Destination
+            (LONG volatile *) // this is the type given in the API doc for this function.
+                &uio.fState,  //  Destination
             1,            //  Exchange Value
             0);           //  Compare value
 
@@ -97,11 +87,6 @@ U_COMMON_API UBool U_EXPORT2 umtx_initImplPreInit(UInitOnce &uio) {
 
 // This function is called by the thread that ran an initialization function,
 // just after completing the function.
-//
-//   success: True:  the inialization succeeded. No further calls to the init
-//                   function will be made.
-//            False: the initializtion failed. The next call to umtx_initOnce()
-//                   will retry the initialization.
 
 U_COMMON_API void U_EXPORT2 umtx_initImplPostInit(UInitOnce &uio) {
     umtx_storeRelease(uio.fState, 2);
@@ -133,6 +118,63 @@ umtx_unlock(UMutex* mutex)
     LeaveCriticalSection(&mutex->fCS);
 }
 
+
+U_CAPI void U_EXPORT2
+umtx_condBroadcast(UConditionVar *condition) {
+    // We require that the associated mutex be held by the caller,
+    //  so access to fWaitCount is protected and safe. No other thread can
+    //  call condWait() while we are here.
+    if (condition->fWaitCount == 0) {
+        return;
+    }
+    ResetEvent(condition->fExitGate);
+    SetEvent(condition->fEntryGate);
+}
+
+U_CAPI void U_EXPORT2
+umtx_condSignal(UConditionVar * /* condition */) {
+    // Function not implemented. There is no immediate requirement from ICU to have it.
+    // Once ICU drops support for Windows XP and Server 2003, ICU Condition Variables will be
+    // changed to be thin wrappers on native Windows CONDITION_VARIABLEs, and this function
+    // becomes trivial to provide.
+    U_ASSERT(FALSE);
+}
+
+U_CAPI void U_EXPORT2
+umtx_condWait(UConditionVar *condition, UMutex *mutex) {
+    if (condition->fEntryGate == NULL) {
+        // Note: because the associated mutex must be locked when calling
+        //       wait, we know that there can not be multiple threads
+        //       running here with the same condition variable.
+        //       Meaning that lazy initialization is safe.
+        U_ASSERT(condition->fExitGate == NULL);
+        condition->fEntryGate = CreateEvent(NULL,   // Security Attributes
+                                            TRUE,   // Manual Reset
+                                            FALSE,  // Initially reset
+                                            NULL);  // Name.
+        U_ASSERT(condition->fEntryGate != NULL);
+        condition->fExitGate = CreateEvent(NULL, TRUE, TRUE, NULL);
+        U_ASSERT(condition->fExitGate != NULL);
+    }
+
+    condition->fWaitCount++;
+    umtx_unlock(mutex);
+    WaitForSingleObject(condition->fEntryGate, INFINITE); 
+    umtx_lock(mutex);
+    condition->fWaitCount--;
+    if (condition->fWaitCount == 0) {
+        // All threads that were waiting at the entry gate have woken up
+        // and moved through. Shut the entry gate and open the exit gate.
+        ResetEvent(condition->fEntryGate);
+        SetEvent(condition->fExitGate);
+    } else {
+        umtx_unlock(mutex);
+        WaitForSingleObject(condition->fExitGate, INFINITE);
+        umtx_lock(mutex);
+    }
+}
+
+
 #elif U_PLATFORM_IMPLEMENTS_POSIX
 
 //-------------------------------------------------------------------------------------------
@@ -169,6 +211,33 @@ umtx_unlock(UMutex* mutex)
     U_ASSERT(sysErr == 0);
 }
 
+
+U_CAPI void U_EXPORT2
+umtx_condWait(UConditionVar *cond, UMutex *mutex) {
+    if (mutex == NULL) {
+        mutex = &globalMutex;
+    }
+    int sysErr = pthread_cond_wait(&cond->fCondition, &mutex->fMutex);
+    (void)sysErr;
+    U_ASSERT(sysErr == 0);
+}
+
+U_CAPI void U_EXPORT2
+umtx_condBroadcast(UConditionVar *cond) {
+    int sysErr = pthread_cond_broadcast(&cond->fCondition);
+    (void)sysErr;
+    U_ASSERT(sysErr == 0);
+}
+
+U_CAPI void U_EXPORT2
+umtx_condSignal(UConditionVar *cond) {
+    int sysErr = pthread_cond_signal(&cond->fCondition);
+    (void)sysErr;
+    U_ASSERT(sysErr == 0);
+}
+
+
+
 U_NAMESPACE_BEGIN
 
 static pthread_mutex_t initMutex = PTHREAD_MUTEX_INITIALIZER;
@@ -266,8 +335,8 @@ umtx_atomic_dec(u_atomic_int32_t *p) {
 
 U_COMMON_API int32_t U_EXPORT2
 umtx_loadAcquire(u_atomic_int32_t &var) {
-    int32_t val = var;
     umtx_lock(&gIncDecMutex);
+    int32_t val = var;
     umtx_unlock(&gIncDecMutex);
     return val;
 }
@@ -275,8 +344,8 @@ umtx_loadAcquire(u_atomic_int32_t &var) {
 U_COMMON_API void U_EXPORT2
 umtx_storeRelease(u_atomic_int32_t &var, int32_t val) {
     umtx_lock(&gIncDecMutex);
-    umtx_unlock(&gIncDecMutex);
     var = val;
+    umtx_unlock(&gIncDecMutex);
 }
 
 U_NAMESPACE_END