webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 164 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/heap/GCActivityCallback.cpp b/Source/JavaScriptCore/heap/GCActivityCallback.cpp
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+++ b/Source/JavaScriptCore/heap/GCActivityCallback.cpp
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+/*
+ * Copyright (C) 2010-2017 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. 
+ * 3.  Neither the name of Apple 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 "GCActivityCallback.h"
+
+#include "HeapInlines.h"
+#include "JSLock.h"
+#include "JSObject.h"
+#include "VM.h"
+
+#if USE(GLIB)
+#include <glib.h>
+#endif
+
+namespace JSC {
+
+bool GCActivityCallback::s_shouldCreateGCTimer = true;
+
+#if USE(CF) || USE(GLIB)
+
+const double timerSlop = 2.0; // Fudge factor to avoid performance cost of resetting timer.
+
+#if USE(CF)
+GCActivityCallback::GCActivityCallback(Heap* heap)
+    : GCActivityCallback(heap->vm())
+{
+}
+#elif USE(GLIB)
+GCActivityCallback::GCActivityCallback(Heap* heap)
+    : GCActivityCallback(heap->vm())
+{
+    g_source_set_ready_time(m_timer.get(), g_get_monotonic_time() + s_decade * G_USEC_PER_SEC);
+}
+#endif
+
+void GCActivityCallback::doWork()
+{
+    Heap* heap = &m_vm->heap;
+    if (!isEnabled())
+        return;
+    
+    JSLockHolder locker(m_vm);
+    if (heap->isDeferred()) {
+        scheduleTimer(0);
+        return;
+    }
+
+    doCollection();
+}
+
+#if USE(CF)
+void GCActivityCallback::scheduleTimer(double newDelay)
+{
+    if (newDelay * timerSlop > m_delay)
+        return;
+    double delta = m_delay - newDelay;
+    m_delay = newDelay;
+    m_nextFireTime = WTF::currentTime() + newDelay;
+    CFRunLoopTimerSetNextFireDate(m_timer.get(), CFRunLoopTimerGetNextFireDate(m_timer.get()) - delta);
+}
+
+void GCActivityCallback::cancelTimer()
+{
+    m_delay = s_decade;
+    m_nextFireTime = 0;
+    CFRunLoopTimerSetNextFireDate(m_timer.get(), CFAbsoluteTimeGetCurrent() + s_decade);
+}
+#elif USE(GLIB)
+void GCActivityCallback::scheduleTimer(double newDelay)
+{
+    ASSERT(newDelay >= 0);
+    if (newDelay * timerSlop > m_delay)
+        return;
+
+    double delta = m_delay - newDelay;
+    m_delay = newDelay;
+    m_nextFireTime = WTF::currentTime() + newDelay;
+
+    gint64 readyTime = g_source_get_ready_time(m_timer.get());
+    g_source_set_ready_time(m_timer.get(), readyTime - delta * G_USEC_PER_SEC);
+}
+
+void GCActivityCallback::cancelTimer()
+{
+    m_delay = s_decade;
+    m_nextFireTime = 0;
+    g_source_set_ready_time(m_timer.get(), g_get_monotonic_time() + s_decade * G_USEC_PER_SEC);
+}
+#endif
+
+void GCActivityCallback::didAllocate(size_t bytes)
+{
+    // The first byte allocated in an allocation cycle will report 0 bytes to didAllocate. 
+    // We pretend it's one byte so that we don't ignore this allocation entirely.
+    if (!bytes)
+        bytes = 1;
+    double bytesExpectedToReclaim = static_cast<double>(bytes) * deathRate();
+    double newDelay = lastGCLength() / gcTimeSlice(bytesExpectedToReclaim);
+    scheduleTimer(newDelay);
+}
+
+void GCActivityCallback::willCollect()
+{
+    cancelTimer();
+}
+
+void GCActivityCallback::cancel()
+{
+    cancelTimer();
+}
+
+#else
+
+GCActivityCallback::GCActivityCallback(Heap* heap)
+    : GCActivityCallback(heap->vm())
+{
+}
+
+void GCActivityCallback::doWork()
+{
+}
+
+void GCActivityCallback::didAllocate(size_t)
+{
+}
+
+void GCActivityCallback::willCollect()
+{
+}
+
+void GCActivityCallback::cancel()
+{
+}
+
+#endif
+
+}
+