From 597984021ca00fd98a0dfe2effd742c6e7bd4190 Mon Sep 17 00:00:00 2001
From: Allan Sandfeld Jensen <allan.jensen@digia.com>
Date: Thu, 14 Mar 2013 14:10:22 +0100
Subject: [Qt] Implement IncrementalSweeper and HeapTimer

https://bugs.webkit.org/show_bug.cgi?id=103996

Reviewed by Simon Hausmann.

Implements the incremental sweeping garbage collection for the Qt platform.

* heap/HeapTimer.cpp:
(JSC::HeapTimer::HeapTimer):
(JSC::HeapTimer::~HeapTimer):
(JSC::HeapTimer::timerEvent):
(JSC::HeapTimer::synchronize):
(JSC::HeapTimer::invalidate):
(JSC::HeapTimer::didStartVMShutdown):
* heap/HeapTimer.h:
(HeapTimer):
* heap/IncrementalSweeper.cpp:
(JSC::IncrementalSweeper::IncrementalSweeper):
(JSC::IncrementalSweeper::scheduleTimer):
* heap/IncrementalSweeper.h:
(IncrementalSweeper):

Change-Id: I47b874c050e08519cf5e3ed5a98a98ac8785971f
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141089 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Reviewed-by: Jocelyn Turcotte <jocelyn.turcotte@digia.com>
---
 Source/JavaScriptCore/heap/HeapTimer.cpp          | 71 ++++++++++++++++++++++-
 Source/JavaScriptCore/heap/HeapTimer.h            | 17 +++++-
 Source/JavaScriptCore/heap/IncrementalSweeper.cpp |  9 ++-
 Source/JavaScriptCore/heap/IncrementalSweeper.h   |  2 +-
 4 files changed, 94 insertions(+), 5 deletions(-)

(limited to 'Source')

diff --git a/Source/JavaScriptCore/heap/HeapTimer.cpp b/Source/JavaScriptCore/heap/HeapTimer.cpp
index 214f86757..d69ee9607 100644
--- a/Source/JavaScriptCore/heap/HeapTimer.cpp
+++ b/Source/JavaScriptCore/heap/HeapTimer.cpp
@@ -33,6 +33,13 @@
 #include <wtf/MainThread.h>
 #include <wtf/Threading.h>
 
+#if PLATFORM(QT)
+#include <QCoreApplication>
+#include <QMutexLocker>
+#include <QThread>
+#include <QTimerEvent>
+#endif
+
 namespace JSC {
 
 #if USE(CF)
@@ -132,8 +139,70 @@ void HeapTimer::didStartVMShutdown()
     delete this;
 }
 
-#else
+#elif PLATFORM(QT)
+
+HeapTimer::HeapTimer(JSGlobalData* globalData)
+    : m_globalData(globalData)
+    , m_newThread(0)
+    , m_mutex(QMutex::NonRecursive)
+{
+    // The HeapTimer might be created before the runLoop is started,
+    // but we need to ensure the thread has an eventDispatcher already.
+    QEventLoop fakeLoop(this);
+}
+
+HeapTimer::~HeapTimer()
+{
+}
+
+void HeapTimer::timerEvent(QTimerEvent*)
+{
+    QMutexLocker lock(&m_mutex);
+    if (m_newThread) {
+        // We need to wait with processing until we are on the right thread.
+        return;
+    }
+
+    APIEntryShim shim(m_globalData, APIEntryShimWithoutLock::DontRefGlobalData);
+    doWork();
+}
 
+void HeapTimer::customEvent(QEvent*)
+{
+    ASSERT(m_newThread);
+    QMutexLocker lock(&m_mutex);
+    moveToThread(m_newThread);
+    m_newThread = 0;
+}
+
+void HeapTimer::synchronize()
+{
+    if (thread() != QThread::currentThread()) {
+        // We can only move from the objects own thread to another, so we fire an
+        // event into the owning thread to trigger the move.
+        // This must be processed before any timerEvents so giving it high priority.
+        QMutexLocker lock(&m_mutex);
+        m_newThread = QThread::currentThread();
+        QCoreApplication::postEvent(this, new QEvent(QEvent::User), Qt::HighEventPriority);
+    }
+}
+
+void HeapTimer::invalidate()
+{
+    QMutexLocker lock(&m_mutex);
+    m_timer.stop();
+}
+
+void HeapTimer::didStartVMShutdown()
+{
+    invalidate();
+    if (thread() == QThread::currentThread())
+        delete this;
+    else
+        deleteLater();
+}
+
+#else
 HeapTimer::HeapTimer(JSGlobalData* globalData)
     : m_globalData(globalData)
 {
diff --git a/Source/JavaScriptCore/heap/HeapTimer.h b/Source/JavaScriptCore/heap/HeapTimer.h
index 88715098a..e0fcda672 100644
--- a/Source/JavaScriptCore/heap/HeapTimer.h
+++ b/Source/JavaScriptCore/heap/HeapTimer.h
@@ -33,13 +33,22 @@
 #include <CoreFoundation/CoreFoundation.h>
 #elif PLATFORM(BLACKBERRY)
 #include <BlackBerryPlatformTimer.h>
+#elif PLATFORM(QT)
+#include <QBasicTimer>
+#include <QMutex>
+#include <QObject>
+#include <QThread>
 #endif
 
 namespace JSC {
 
 class JSGlobalData;
-    
+
+#if PLATFORM(QT)
+class HeapTimer : public QObject {
+#else
 class HeapTimer {
+#endif
 public:
 #if USE(CF)
     HeapTimer(JSGlobalData*, CFRunLoopRef);
@@ -69,6 +78,12 @@ protected:
     void timerDidFire();
 
     BlackBerry::Platform::Timer<HeapTimer> m_timer;
+#elif PLATFORM(QT)
+    void timerEvent(QTimerEvent*);
+    void customEvent(QEvent*);
+    QBasicTimer m_timer;
+    QThread* m_newThread;
+    QMutex m_mutex;
 #endif
     
 private:
diff --git a/Source/JavaScriptCore/heap/IncrementalSweeper.cpp b/Source/JavaScriptCore/heap/IncrementalSweeper.cpp
index 4aec4dd51..41bc7f5e4 100644
--- a/Source/JavaScriptCore/heap/IncrementalSweeper.cpp
+++ b/Source/JavaScriptCore/heap/IncrementalSweeper.cpp
@@ -37,7 +37,7 @@
 
 namespace JSC {
 
-#if USE(CF) || PLATFORM(BLACKBERRY)
+#if USE(CF) || PLATFORM(BLACKBERRY) || PLATFORM(QT)
 
 static const double sweepTimeSlice = .01; // seconds
 static const double sweepTimeTotal = .10;
@@ -67,11 +67,12 @@ void IncrementalSweeper::cancelTimer()
     CFRunLoopTimerSetNextFireDate(m_timer.get(), CFAbsoluteTimeGetCurrent() + s_decade);
 }
 
-#elif PLATFORM(BLACKBERRY)
+#elif PLATFORM(BLACKBERRY) || PLATFORM(QT)
    
 IncrementalSweeper::IncrementalSweeper(Heap* heap)
     : HeapTimer(heap->globalData())
     , m_currentBlockToSweepIndex(0)
+    , m_blocksToSweep(heap->m_blockSnapshot)
 {
 }
 
@@ -82,7 +83,11 @@ IncrementalSweeper* IncrementalSweeper::create(Heap* heap)
 
 void IncrementalSweeper::scheduleTimer()
 {
+#if PLATFORM(QT)
+    m_timer.start(sweepTimeSlice * sweepTimeMultiplier * 1000, this);
+#else
     m_timer.start(sweepTimeSlice * sweepTimeMultiplier);
+#endif
 }
 
 void IncrementalSweeper::cancelTimer()
diff --git a/Source/JavaScriptCore/heap/IncrementalSweeper.h b/Source/JavaScriptCore/heap/IncrementalSweeper.h
index 5b9267bc7..7b0ae99ab 100644
--- a/Source/JavaScriptCore/heap/IncrementalSweeper.h
+++ b/Source/JavaScriptCore/heap/IncrementalSweeper.h
@@ -46,7 +46,7 @@ public:
     void willFinishSweeping();
 
 private:
-#if USE(CF) || PLATFORM(BLACKBERRY)
+#if USE(CF) || PLATFORM(BLACKBERRY) || PLATFORM(QT)
 #if USE(CF)
     IncrementalSweeper(Heap*, CFRunLoopRef);
 #else
-- 
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