JavaScriptCore-521.tar.gz

[apple/javascriptcore.git] / wtf / MainThread.cpp

diff --git a/wtf/MainThread.cpp b/wtf/MainThread.cpp
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+/*
+ * Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 2.  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "MainThread.h"
+
+#include "StdLibExtras.h"
+#include "Threading.h"
+#include "Vector.h"
+
+namespace WTF {
+
+struct FunctionWithContext {
+    MainThreadFunction* function;
+    void* context;
+    ThreadCondition* syncFlag;
+
+    FunctionWithContext(MainThreadFunction* function = 0, void* context = 0, ThreadCondition* syncFlag = 0)
+        : function(function)
+        , context(context)
+        , syncFlag(syncFlag)
+    { 
+    }
+};
+
+typedef Vector<FunctionWithContext> FunctionQueue;
+
+static bool callbacksPaused; // This global variable is only accessed from main thread.
+
+Mutex& mainThreadFunctionQueueMutex()
+{
+    DEFINE_STATIC_LOCAL(Mutex, staticMutex, ());
+    return staticMutex;
+}
+
+static FunctionQueue& functionQueue()
+{
+    DEFINE_STATIC_LOCAL(FunctionQueue, staticFunctionQueue, ());
+    return staticFunctionQueue;
+}
+
+#if !PLATFORM(WIN)
+void initializeMainThread()
+{
+    mainThreadFunctionQueueMutex();
+}
+#endif
+
+void dispatchFunctionsFromMainThread()
+{
+    ASSERT(isMainThread());
+
+    if (callbacksPaused)
+        return;
+
+    FunctionQueue queueCopy;
+    {
+        MutexLocker locker(mainThreadFunctionQueueMutex());
+        queueCopy.swap(functionQueue());
+    }
+
+    for (unsigned i = 0; i < queueCopy.size(); ++i) {
+        FunctionWithContext& invocation = queueCopy[i];
+        invocation.function(invocation.context);
+        if (invocation.syncFlag)
+            invocation.syncFlag->signal();
+    }
+}
+
+void callOnMainThread(MainThreadFunction* function, void* context)
+{
+    ASSERT(function);
+
+    {
+        MutexLocker locker(mainThreadFunctionQueueMutex());
+        functionQueue().append(FunctionWithContext(function, context));
+    }
+
+    scheduleDispatchFunctionsOnMainThread();
+}
+
+void callOnMainThreadAndWait(MainThreadFunction* function, void* context)
+{
+    ASSERT(function);
+
+    if (isMainThread()) {
+        function(context);
+        return;
+    }
+
+    ThreadCondition syncFlag;
+    Mutex conditionMutex;
+
+    {
+        MutexLocker locker(mainThreadFunctionQueueMutex());
+        functionQueue().append(FunctionWithContext(function, context, &syncFlag));
+        conditionMutex.lock();
+    }
+
+    scheduleDispatchFunctionsOnMainThread();
+    syncFlag.wait(conditionMutex);
+}
+
+void setMainThreadCallbacksPaused(bool paused)
+{
+    ASSERT(isMainThread());
+
+    if (callbacksPaused == paused)
+        return;
+
+    callbacksPaused = paused;
+
+    if (!callbacksPaused)
+        scheduleDispatchFunctionsOnMainThread();
+}
+
+} // namespace WTF