webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 131 insertions, 0 deletions

diff --git a/Source/WebCore/page/ResourceUsageThread.cpp b/Source/WebCore/page/ResourceUsageThread.cpp
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+++ b/Source/WebCore/page/ResourceUsageThread.cpp
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+/*
+ * Copyright (C) 2016 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. 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 INC. 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 "ResourceUsageThread.h"
+
+#if ENABLE(RESOURCE_USAGE)
+
+#include "CommonVM.h"
+#include "JSDOMWindow.h"
+#include <thread>
+#include <wtf/MainThread.h>
+#include <wtf/Vector.h>
+
+namespace WebCore {
+
+ResourceUsageThread::ResourceUsageThread()
+{
+}
+
+ResourceUsageThread& ResourceUsageThread::singleton()
+{
+    static NeverDestroyed<ResourceUsageThread> resourceUsageThread;
+    return resourceUsageThread;
+}
+
+void ResourceUsageThread::addObserver(void* key, std::function<void (const ResourceUsageData&)> function)
+{
+    auto& resourceUsageThread = ResourceUsageThread::singleton();
+    resourceUsageThread.createThreadIfNeeded();
+
+    {
+        LockHolder locker(resourceUsageThread.m_lock);
+        bool wasEmpty = resourceUsageThread.m_observers.isEmpty();
+        resourceUsageThread.m_observers.set(key, function);
+
+        if (wasEmpty)
+            resourceUsageThread.m_condition.notifyAll();
+    }
+}
+
+void ResourceUsageThread::removeObserver(void* key)
+{
+    auto& resourceUsageThread = ResourceUsageThread::singleton();
+
+    {
+        LockHolder locker(resourceUsageThread.m_lock);
+        resourceUsageThread.m_observers.remove(key);
+    }
+}
+
+void ResourceUsageThread::waitUntilObservers()
+{
+    LockHolder locker(m_lock);
+    while (m_observers.isEmpty())
+        m_condition.wait(m_lock);
+}
+
+void ResourceUsageThread::notifyObservers(ResourceUsageData&& data)
+{
+    callOnMainThread([data = WTFMove(data)]() mutable {
+        Vector<std::function<void (const ResourceUsageData&)>> functions;
+        
+        {
+            auto& resourceUsageThread = ResourceUsageThread::singleton();
+            LockHolder locker(resourceUsageThread.m_lock);
+            copyValuesToVector(resourceUsageThread.m_observers, functions);
+        }
+
+        for (auto& function : functions)
+            function(data);
+    });
+}
+
+void ResourceUsageThread::createThreadIfNeeded()
+{
+    if (m_threadIdentifier)
+        return;
+
+    m_vm = &commonVM();
+    m_threadIdentifier = createThread(threadCallback, this, "WebCore: ResourceUsage");
+}
+
+void ResourceUsageThread::threadCallback(void* resourceUsageThread)
+{
+    static_cast<ResourceUsageThread*>(resourceUsageThread)->threadBody();
+}
+
+NO_RETURN void ResourceUsageThread::threadBody()
+{
+    while (true) {
+        // Only do work if we have observers.
+        waitUntilObservers();
+
+        auto start = std::chrono::system_clock::now();
+
+        ResourceUsageData data;
+        platformThreadBody(m_vm, data);
+        notifyObservers(WTFMove(data));
+
+        auto duration = std::chrono::system_clock::now() - start;
+        auto difference = 500ms - duration;
+        std::this_thread::sleep_for(difference);
+    }
+}
+
+} // namespace WebCore
+
+#endif // ENABLE(RESOURCE_USAGE)