webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 115 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/heap/FullGCActivityCallback.cpp b/Source/JavaScriptCore/heap/FullGCActivityCallback.cpp
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index 000000000..e57dd3a1c
--- /dev/null
+++ b/Source/JavaScriptCore/heap/FullGCActivityCallback.cpp
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+/*
+ * Copyright (C) 2014-2017 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 "FullGCActivityCallback.h"
+
+#include "VM.h"
+
+namespace JSC {
+
+#if USE(CF) || USE(GLIB)
+
+#if !PLATFORM(IOS)
+const double pagingTimeOut = 0.1; // Time in seconds to allow opportunistic timer to iterate over all blocks to see if the Heap is paged out.
+#endif
+
+FullGCActivityCallback::FullGCActivityCallback(Heap* heap)
+    : GCActivityCallback(heap)
+{
+}
+
+void FullGCActivityCallback::doCollection()
+{
+    Heap& heap = m_vm->heap;
+    m_didSyncGCRecently = false;
+
+#if !PLATFORM(IOS)
+    double startTime = WTF::monotonicallyIncreasingTime();
+    if (heap.isPagedOut(startTime + pagingTimeOut)) {
+        cancel();
+        heap.increaseLastFullGCLength(Seconds(pagingTimeOut));
+        return;
+    }
+#endif
+
+    heap.collectAsync(CollectionScope::Full);
+}
+
+double FullGCActivityCallback::lastGCLength()
+{
+    return m_vm->heap.lastFullGCLength().seconds();
+}
+
+double FullGCActivityCallback::deathRate()
+{
+    Heap* heap = &m_vm->heap;
+    size_t sizeBefore = heap->sizeBeforeLastFullCollection();
+    size_t sizeAfter = heap->sizeAfterLastFullCollection();
+    if (!sizeBefore)
+        return 1.0;
+    if (sizeAfter > sizeBefore) {
+        // GC caused the heap to grow(!)
+        // This could happen if the we visited more extra memory than was reported allocated.
+        // We don't return a negative death rate, since that would schedule the next GC in the past.
+        return 0;
+    }
+    return static_cast<double>(sizeBefore - sizeAfter) / static_cast<double>(sizeBefore);
+}
+
+double FullGCActivityCallback::gcTimeSlice(size_t bytes)
+{
+    return std::min((static_cast<double>(bytes) / MB) * Options::percentCPUPerMBForFullTimer(), Options::collectionTimerMaxPercentCPU());
+}
+
+#else
+
+FullGCActivityCallback::FullGCActivityCallback(Heap* heap)
+    : GCActivityCallback(heap)
+{
+}
+
+void FullGCActivityCallback::doCollection()
+{
+}
+
+double FullGCActivityCallback::lastGCLength()
+{
+    return 0;
+}
+
+double FullGCActivityCallback::deathRate()
+{
+    return 0;
+}
+
+double FullGCActivityCallback::gcTimeSlice(size_t)
+{
+    return 0;
+}
+
+#endif // USE(CF) || USE(GLIB)
+
+} // namespace JSC