1 files changed, 135 insertions, 0 deletions
diff --git a/Source/WebCore/platform/win/MemoryPressureHandlerWin.cpp b/Source/WebCore/platform/win/MemoryPressureHandlerWin.cpp
new file mode 100644
index 000000000..0d523b88a
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+++ b/Source/WebCore/platform/win/MemoryPressureHandlerWin.cpp
@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2015 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. ``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
+ * 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 "MemoryPressureHandler.h"
+
+#include <WebCore/Timer.h>
+#include <WebCore/Win32Handle.h>
+#include <psapi.h>
+#include <wtf/NeverDestroyed.h>
+
+namespace WebCore {
+
+// We create a timer for checking the memory usage at regular intervals.
+
+class CheckMemoryTimer : public TimerBase {
+public:
+    CheckMemoryTimer(MemoryPressureHandler&);
+
+private:
+    virtual void fired();
+
+    void handleMemoryLow();
+
+    MemoryPressureHandler& m_pressureHandler;
+    Win32Handle m_lowMemoryHandle;
+};
+
+CheckMemoryTimer::CheckMemoryTimer(MemoryPressureHandler& pressureHandler)
+    : m_pressureHandler(pressureHandler)
+{
+    m_lowMemoryHandle = CreateMemoryResourceNotification(LowMemoryResourceNotification);
+}
+
+void CheckMemoryTimer::fired()
+{
+    m_pressureHandler.setUnderMemoryPressure(false);
+
+    BOOL memoryLow;
+
+    if (QueryMemoryResourceNotification(m_lowMemoryHandle.get(), &memoryLow) && memoryLow) {
+        handleMemoryLow();
+        return;
+    }
+
+#if CPU(X86)
+    PROCESS_MEMORY_COUNTERS_EX counters;
+
+    if (!GetProcessMemoryInfo(GetCurrentProcess(), reinterpret_cast<PROCESS_MEMORY_COUNTERS*>(&counters), sizeof(counters)))
+        return;
+
+    // On Windows, 32-bit processes have 2GB of memory available, where some is used by the system.
+    // Debugging has shown that allocations might fail and cause crashes when memory usage is > ~1GB.
+    const int maxMemoryUsageBytes = 1024 * 1024 * 1024;
+
+    if (counters.PrivateUsage > maxMemoryUsageBytes)
+        handleMemoryLow();
+#endif
+}
+
+void CheckMemoryTimer::handleMemoryLow()
+{
+    m_pressureHandler.setUnderMemoryPressure(true);
+    m_pressureHandler.releaseMemory(Critical::Yes);
+}
+
+void MemoryPressureHandler::platformReleaseMemory(Critical)
+{
+}
+
+static std::unique_ptr<CheckMemoryTimer>& memCheckTimer()
+{
+    static NeverDestroyed<std::unique_ptr<CheckMemoryTimer>> memCheckTimer;
+    return memCheckTimer;
+}
+
+void MemoryPressureHandler::install()
+{
+    m_installed = true;
+    memCheckTimer() = std::make_unique<CheckMemoryTimer>(*this);
+    memCheckTimer()->startRepeating(60.0);
+}
+
+void MemoryPressureHandler::uninstall()
+{
+    if (!m_installed)
+        return;
+
+    memCheckTimer() = nullptr;
+    m_installed = false;
+}
+
+void MemoryPressureHandler::holdOff(unsigned seconds)
+{
+}
+
+void MemoryPressureHandler::respondToMemoryPressure(Critical critical, Synchronous synchronous)
+{
+    uninstall();
+
+    m_lowMemoryHandler(critical, synchronous);
+}
+
+size_t MemoryPressureHandler::ReliefLogger::platformMemoryUsage()
+{
+    return 0;
+}
+
+void MemoryPressureHandler::ReliefLogger::platformLog()
+{
+}
+
+} // namespace WebCore