From a401d0756f6ac3cee5597d5528515061326c3bfa Mon Sep 17 00:00:00 2001 From: Simon Hausmann Date: Tue, 13 Dec 2011 10:04:40 +0100 Subject: Fix that QJSEngine cannot be used from threads other than the gui thread Implicitly allocate & enter an isolate per thread if needed, store it in TLS and exit it upon thread destruction. As the code that represents QObject dependencies in the GC through implicit dependencies uses its own context, its per-thread data is folded into the v8engine TLS to ensure that it is destructed before the isolate is exited. Task-number: QTBUG-23099 Change-Id: I86538b54939b2fe64db843052eac04c7fd31813e Reviewed-by: Aaron Kennedy --- src/declarative/qml/v8/qv8engine.cpp | 80 ++++++++++++++++++++++-------------- src/declarative/qml/v8/qv8engine_p.h | 29 +++++++------ 2 files changed, 63 insertions(+), 46 deletions(-) (limited to 'src/declarative/qml/v8') diff --git a/src/declarative/qml/v8/qv8engine.cpp b/src/declarative/qml/v8/qv8engine.cpp index 7d66e5161e..7c3dc1ddc8 100644 --- a/src/declarative/qml/v8/qv8engine.cpp +++ b/src/declarative/qml/v8/qv8engine.cpp @@ -131,6 +131,8 @@ QV8Engine::QV8Engine(QJSEngine* qq, QJSEngine::ContextOwnership ownership) v8args.append(" --nobreakpoint_relocation"); v8::V8::SetFlagsFromString(v8args.constData(), v8args.length()); + ensurePerThreadIsolate(); + v8::HandleScope handle_scope; m_context = (ownership == QJSEngine::CreateNewContext) ? v8::Context::New() : v8::Persistent::New(v8::Context::GetCurrent()); qPersistentRegister(m_context); @@ -767,6 +769,25 @@ QDateTime QV8Engine::qtDateTimeFromJsDate(double jsDate) return convertedUTC.toLocalTime(); } +static QThreadStorage perThreadEngineData; + +bool QV8Engine::hasThreadData() +{ + return perThreadEngineData.hasLocalData(); +} + +QV8Engine::ThreadData *QV8Engine::threadData() +{ + Q_ASSERT(perThreadEngineData.hasLocalData()); + return perThreadEngineData.localData(); +} + +void QV8Engine::ensurePerThreadIsolate() +{ + if (!perThreadEngineData.hasLocalData()) + perThreadEngineData.setLocalData(new ThreadData); +} + void QV8Engine::initDeclarativeGlobalObject() { v8::HandleScope handels; @@ -1430,37 +1451,17 @@ qint64 QV8Engine::stopTimer(const QString &timerName, bool *wasRunning) return m_time.elapsed() - startedAt; } -QThreadStorage QV8GCCallback::threadData; -void QV8GCCallback::initializeThreadData() -{ - QV8GCCallback::ThreadData *newThreadData = new QV8GCCallback::ThreadData; - threadData.setLocalData(newThreadData); -} - void QV8GCCallback::registerGcPrologueCallback() { - if (!threadData.hasLocalData()) - initializeThreadData(); - - QV8GCCallback::ThreadData *td = threadData.localData(); + QV8Engine::ThreadData *td = QV8Engine::threadData(); if (!td->gcPrologueCallbackRegistered) { td->gcPrologueCallbackRegistered = true; + if (!td->referencer) + td->referencer = new QV8GCCallback::Referencer; v8::V8::AddGCPrologueCallback(QV8GCCallback::garbageCollectorPrologueCallback, v8::kGCTypeMarkSweepCompact); } } -void QV8GCCallback::releaseWorkerThreadGcPrologueCallbackData() -{ - // Note that only worker-thread implementations with their - // own QV8Engine should explicitly release the Referencer - // by calling this functions. - Q_ASSERT_X(v8::Isolate::GetCurrent(), "QV8GCCallback::releaseWorkerThreadGcPrologueCallbackData()", "called after v8::Isolate has exited"); - if (threadData.hasLocalData()) { - QV8GCCallback::ThreadData *td = threadData.localData(); - td->referencer.dispose(); - } -} - QV8GCCallback::Node::Node(PrologueCallback callback) : prologueCallback(callback) { @@ -1569,32 +1570,49 @@ v8::Persistent *QV8GCCallback::Referencer::findOwnerAndStrength(QObj */ void QV8GCCallback::garbageCollectorPrologueCallback(v8::GCType, v8::GCCallbackFlags) { - if (!threadData.hasLocalData()) + if (!QV8Engine::hasThreadData()) return; - QV8GCCallback::ThreadData *td = threadData.localData(); + QV8Engine::ThreadData *td = QV8Engine::threadData(); + Q_ASSERT(td->referencer); QV8GCCallback::Node *currNode = td->gcCallbackNodes.first(); while (currNode) { // The client which adds itself to the list is responsible // for maintaining the correct implicit references in the // specified callback. - currNode->prologueCallback(&td->referencer, currNode); + currNode->prologueCallback(td->referencer, currNode); currNode = td->gcCallbackNodes.next(currNode); } } void QV8GCCallback::addGcCallbackNode(QV8GCCallback::Node *node) { - if (!threadData.hasLocalData()) - initializeThreadData(); - - QV8GCCallback::ThreadData *td = threadData.localData(); + QV8Engine::ThreadData *td = QV8Engine::threadData(); td->gcCallbackNodes.insert(node); } -QV8GCCallback::ThreadData::~ThreadData() +QV8Engine::ThreadData::ThreadData() + : referencer(0) + , gcPrologueCallbackRegistered(false) { + if (!v8::Isolate::GetCurrent()) { + isolate = v8::Isolate::New(); + isolate->Enter(); + } else { + isolate = 0; + } +} + +QV8Engine::ThreadData::~ThreadData() +{ + delete referencer; + referencer = 0; + if (isolate) { + isolate->Exit(); + isolate->Dispose(); + isolate = 0; + } } QT_END_NAMESPACE diff --git a/src/declarative/qml/v8/qv8engine_p.h b/src/declarative/qml/v8/qv8engine_p.h index 7df4c523c0..4e6d3de91f 100644 --- a/src/declarative/qml/v8/qv8engine_p.h +++ b/src/declarative/qml/v8/qv8engine_p.h @@ -230,7 +230,6 @@ private: public: static void garbageCollectorPrologueCallback(v8::GCType, v8::GCCallbackFlags); static void registerGcPrologueCallback(); - static void releaseWorkerThreadGcPrologueCallbackData(); class Q_AUTOTEST_EXPORT Referencer { public: @@ -243,7 +242,7 @@ public: static v8::Persistent *findOwnerAndStrength(QObject *qobjectOwner, bool *shouldBeStrong); v8::Persistent strongReferencer; v8::Persistent context; - friend class QV8GCCallback::ThreadData; + friend class QV8GCCallback; }; class Q_AUTOTEST_EXPORT Node { @@ -257,19 +256,6 @@ public: }; static void addGcCallbackNode(Node *node); - -private: - class ThreadData { - public: - ThreadData() : gcPrologueCallbackRegistered(false) { } - ~ThreadData(); - Referencer referencer; - bool gcPrologueCallbackRegistered; - QIntrusiveList gcCallbackNodes; - }; - - static void initializeThreadData(); - static QThreadStorage threadData; }; class Q_DECLARATIVE_EXPORT QV8Engine @@ -465,6 +451,19 @@ public: static QDateTime qtDateTimeFromJsDate(double jsDate); + struct ThreadData { + ThreadData(); + ~ThreadData(); + v8::Isolate* isolate; + QV8GCCallback::Referencer* referencer; + bool gcPrologueCallbackRegistered; + QIntrusiveList gcCallbackNodes; + }; + + static bool hasThreadData(); + static ThreadData* threadData(); + static void ensurePerThreadIsolate(); + protected: QJSEngine* q; QDeclarativeEngine *m_engine; -- cgit v1.2.3