webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 226 insertions, 0 deletions

diff --git a/Source/WebCore/page/MemoryRelease.cpp b/Source/WebCore/page/MemoryRelease.cpp
new file mode 100644
index 000000000..36612a81a
--- /dev/null
+++ b/Source/WebCore/page/MemoryRelease.cpp
@@ -0,0 +1,226 @@
+/*
+ * Copyright (C) 2011, 2014 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 "MemoryRelease.h"
+
+#include "CSSValuePool.h"
+#include "Chrome.h"
+#include "ChromeClient.h"
+#include "CommonVM.h"
+#include "Document.h"
+#include "FontCache.h"
+#include "GCController.h"
+#include "HTMLMediaElement.h"
+#include "InlineStyleSheetOwner.h"
+#include "InspectorInstrumentation.h"
+#include "Logging.h"
+#include "MainFrame.h"
+#include "MemoryCache.h"
+#include "Page.h"
+#include "PageCache.h"
+#include "RenderTheme.h"
+#include "ScrollingThread.h"
+#include "StyleScope.h"
+#include "StyledElement.h"
+#include "WorkerThread.h"
+#include <wtf/FastMalloc.h>
+
+#if PLATFORM(COCOA)
+#include "ResourceUsageThread.h"
+#endif
+
+namespace WebCore {
+
+static void releaseNoncriticalMemory()
+{
+    RenderTheme::defaultTheme()->purgeCaches();
+
+    FontCache::singleton().purgeInactiveFontData();
+
+    clearWidthCaches();
+
+    for (auto* document : Document::allDocuments())
+        document->clearSelectorQueryCache();
+
+    MemoryCache::singleton().pruneDeadResourcesToSize(0);
+
+    InlineStyleSheetOwner::clearCache();
+}
+
+static void releaseCriticalMemory(Synchronous synchronous)
+{
+    // Right now, the only reason we call release critical memory while not under memory pressure is if the process is about to be suspended.
+    PruningReason pruningReason = MemoryPressureHandler::singleton().isUnderMemoryPressure() ? PruningReason::MemoryPressure : PruningReason::ProcessSuspended;
+    PageCache::singleton().pruneToSizeNow(0, pruningReason);
+
+    MemoryCache::singleton().pruneLiveResourcesToSize(0, /*shouldDestroyDecodedDataForAllLiveResources*/ true);
+
+    CSSValuePool::singleton().drain();
+
+    Vector<RefPtr<Document>> documents;
+    copyToVector(Document::allDocuments(), documents);
+    for (auto& document : documents)
+        document->styleScope().clearResolver();
+
+    GCController::singleton().deleteAllCode(JSC::DeleteAllCodeIfNotCollecting);
+
+#if ENABLE(VIDEO)
+    for (auto* mediaElement : HTMLMediaElement::allMediaElements()) {
+        if (mediaElement->paused())
+            mediaElement->purgeBufferedDataIfPossible();
+    }
+#endif
+
+    if (synchronous == Synchronous::Yes) {
+        GCController::singleton().garbageCollectNow();
+    } else {
+#if PLATFORM(IOS)
+        GCController::singleton().garbageCollectNowIfNotDoneRecently();
+#else
+        GCController::singleton().garbageCollectSoon();
+#endif
+    }
+
+    // We reduce tiling coverage while under memory pressure, so make sure to drop excess tiles ASAP.
+    Page::forEachPage([](Page& page) {
+        page.chrome().client().scheduleCompositingLayerFlush();
+    });
+}
+
+void releaseMemory(Critical critical, Synchronous synchronous)
+{
+    if (critical == Critical::Yes)
+        releaseCriticalMemory(synchronous);
+
+    releaseNoncriticalMemory();
+
+    platformReleaseMemory(critical);
+
+    // FastMalloc has lock-free thread specific caches that can only be cleared from the thread itself.
+    WorkerThread::releaseFastMallocFreeMemoryInAllThreads();
+#if ENABLE(ASYNC_SCROLLING) && !PLATFORM(IOS)
+    ScrollingThread::dispatch([]() {
+        WTF::releaseFastMallocFreeMemory();
+    });
+#endif
+    WTF::releaseFastMallocFreeMemory();
+
+#if ENABLE(RESOURCE_USAGE)
+    Page::forEachPage([&](Page& page) {
+        InspectorInstrumentation::didHandleMemoryPressure(page, critical);
+    });
+#endif
+}
+
+#if !RELEASE_LOG_DISABLED
+static unsigned pageCount()
+{
+    unsigned count = 0;
+    Page::forEachPage([&] (Page& page) {
+        if (!page.isUtilityPage())
+            ++count;
+    });
+    return count;
+}
+#endif
+
+void logMemoryStatisticsAtTimeOfDeath()
+{
+#if !RELEASE_LOG_DISABLED
+#if PLATFORM(COCOA)
+    auto pageSize = vmPageSize();
+    auto pages = pagesPerVMTag();
+
+    RELEASE_LOG(MemoryPressure, "Dirty memory per VM tag at time of death:");
+    for (unsigned i = 0; i < 256; ++i) {
+        size_t dirty = pages[i].dirty * pageSize;
+        if (!dirty)
+            continue;
+        String tagName = displayNameForVMTag(i);
+        if (!tagName)
+            tagName = String::format("Tag %u", i);
+        RELEASE_LOG(MemoryPressure, "%16s: %lu MB", tagName.latin1().data(), dirty / MB);
+    }
+#endif
+
+    auto& vm = commonVM();
+    RELEASE_LOG(MemoryPressure, "Memory usage statistics at time of death:");
+    RELEASE_LOG(MemoryPressure, "GC heap size: %zu", vm.heap.size());
+    RELEASE_LOG(MemoryPressure, "GC heap extra memory size: %zu", vm.heap.extraMemorySize());
+#if ENABLE(RESOURCE_USAGE)
+    RELEASE_LOG(MemoryPressure, "GC heap external memory: %zu", vm.heap.externalMemorySize());
+#endif
+    RELEASE_LOG(MemoryPressure, "Global object count: %zu", vm.heap.globalObjectCount());
+
+    RELEASE_LOG(MemoryPressure, "Page count: %u", pageCount());
+    RELEASE_LOG(MemoryPressure, "Document count: %u", Document::allDocuments().size());
+    RELEASE_LOG(MemoryPressure, "Live JavaScript objects:");
+    for (auto& it : *vm.heap.objectTypeCounts())
+        RELEASE_LOG(MemoryPressure, "  %s: %d", it.key, it.value);
+#endif
+}
+
+void didExceedMemoryLimitAndFailedToRecover()
+{
+    RELEASE_LOG(MemoryPressure, "Crashing non-visible process due to excessive memory usage + inability to free up memory below panic threshold.");
+    logMemoryStatisticsAtTimeOfDeath();
+    CRASH();
+}
+
+bool processIsEligibleForMemoryKill()
+{
+    bool hasVisiblePages = false;
+    bool hasAudiblePages = false;
+    bool hasMainFrameNavigatedInTheLastHour = false;
+
+    auto now = MonotonicTime::now();
+    Page::forEachPage([&] (Page& page) {
+        if (page.isUtilityPage())
+            return;
+        if (page.isVisible())
+            hasVisiblePages = true;
+        if (page.activityState() & ActivityState::IsAudible)
+            hasAudiblePages = true;
+        if (auto timeOfLastCompletedLoad = page.mainFrame().timeOfLastCompletedLoad()) {
+            if (now - timeOfLastCompletedLoad <= Seconds::fromMinutes(60))
+                hasMainFrameNavigatedInTheLastHour = true;
+        }
+    });
+
+    bool eligible = !hasVisiblePages && !hasAudiblePages && !hasMainFrameNavigatedInTheLastHour;
+    if (!eligible)
+        RELEASE_LOG(MemoryPressure, "Process not eligible for panic memory kill. Reasons: hasVisiblePages=%u, hasAudiblePages=%u, hasMainFrameNavigatedInTheLastHour=%u", hasVisiblePages, hasAudiblePages, hasMainFrameNavigatedInTheLastHour);
+
+    return eligible;
+}
+
+#if !PLATFORM(COCOA)
+void platformReleaseMemory(Critical) { }
+void jettisonExpensiveObjectsOnTopLevelNavigation() { }
+void registerMemoryReleaseNotifyCallbacks() { }
+#endif
+
+} // namespace WebCore