Turn execution contexts into Managed objects

This finally gives proper memory management for ExecutionContexts.
So far they had been garbage collected but where still allocated
using standard malloc/free(). This allows us to collect the
contexts faster and speed up context creation.

Change-Id: I02e642391d55eaa59ab3f4c2720a2ac71259caf4
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

9 files changed, 85 insertions, 62 deletions

diff --git a/src/qml/jsruntime/qv4argumentsobject.cpp b/src/qml/jsruntime/qv4argumentsobject.cpp
index 4bf4d19576..749509c353 100644
--- a/src/qml/jsruntime/qv4argumentsobject.cpp
+++ b/src/qml/jsruntime/qv4argumentsobject.cpp
@@ -240,7 +240,7 @@ ReturnedValue ArgumentsSetterFunction::call(Managed *setter, CallData *callData)
 void ArgumentsObject::markObjects(Managed *that, ExecutionEngine *e)
 {
     ArgumentsObject *o = static_cast<ArgumentsObject *>(that);
-    o->context->mark();
+    o->context->mark(e);
     for (int i = 0; i < o->mappedArguments.size(); ++i)
         o->mappedArguments.at(i).mark(e);
 
diff --git a/src/qml/jsruntime/qv4context.cpp b/src/qml/jsruntime/qv4context.cpp
index 97247ad368..372c9ce54b 100644
--- a/src/qml/jsruntime/qv4context.cpp
+++ b/src/qml/jsruntime/qv4context.cpp
@@ -51,9 +51,33 @@
 
 using namespace QV4;
 
+const ManagedVTable ExecutionContext::static_vtbl =
+{
+    call,
+    construct,
+    markObjects,
+    destroy,
+    0 /*collectDeletables*/,
+    hasInstance,
+    0,
+    0,
+    0,
+    0,
+    0,
+    0,
+    0,
+    0,
+    0,
+    0,
+    isEqualTo,
+    0,
+    "ExecutionContext",
+};
+
 CallContext *ExecutionContext::newCallContext(FunctionObject *function, CallData *callData)
 {
-    CallContext *c = static_cast<CallContext *>(engine->memoryManager->allocContext(requiredMemoryForExecutionContect(function, callData->argc)));
+    CallContext *c = static_cast<CallContext *>(engine->memoryManager->allocManaged(requiredMemoryForExecutionContect(function, callData->argc)));
+    c->init();
 
     engine->current = c;
 
@@ -63,7 +87,6 @@ CallContext *ExecutionContext::newCallContext(FunctionObject *function, CallData
     c->realArgumentCount = callData->argc;
 
     c->strictMode = function->strictMode;
-    c->marked = false;
     c->outer = function->scope;
 #ifndef QT_NO_DEBUG
     assert(c->outer->next != (ExecutionContext *)0x1);
@@ -92,7 +115,7 @@ CallContext *ExecutionContext::newCallContext(FunctionObject *function, CallData
 
 WithContext *ExecutionContext::newWithContext(ObjectRef with)
 {
-    WithContext *w = static_cast<WithContext *>(engine->memoryManager->allocContext(sizeof(WithContext)));
+    WithContext *w = new (engine->memoryManager) WithContext;
     engine->current = w;
     w->initWithContext(this, with);
     return w;
@@ -100,7 +123,7 @@ WithContext *ExecutionContext::newWithContext(ObjectRef with)
 
 CatchContext *ExecutionContext::newCatchContext(const StringRef exceptionVarName, const ValueRef exceptionValue)
 {
-    CatchContext *c = static_cast<CatchContext *>(engine->memoryManager->allocContext(sizeof(CatchContext)));
+    CatchContext *c = new (engine->memoryManager) CatchContext;
     engine->current = c;
     c->initCatchContext(this, exceptionVarName, exceptionValue);
     return c;
@@ -108,7 +131,8 @@ CatchContext *ExecutionContext::newCatchContext(const StringRef exceptionVarName
 
 CallContext *ExecutionContext::newQmlContext(FunctionObject *f, ObjectRef qml)
 {
-    CallContext *c = static_cast<CallContext *>(engine->memoryManager->allocContext(requiredMemoryForExecutionContect(f, 0)));
+    CallContext *c = static_cast<CallContext *>(engine->memoryManager->allocManaged(requiredMemoryForExecutionContect(f, 0)));
+    c->init();
 
     engine->current = c;
     c->initQmlContext(this, qml, f);
@@ -184,6 +208,7 @@ void GlobalContext::initGlobalContext(ExecutionEngine *eng)
     callData->tag = QV4::Value::_Integer_Type;
     callData->argc = 0;
     callData->thisObject = eng->globalObject;
+    callData->args[0] = Encode::undefined();
     global = 0;
 }
 
@@ -222,7 +247,6 @@ void CallContext::initQmlContext(ExecutionContext *parentContext, ObjectRef qml,
     this->callData->thisObject = Primitive::undefinedValue();
 
     strictMode = true;
-    marked = false;
     this->outer = function->scope;
 #ifndef QT_NO_DEBUG
     assert(outer->next != (ExecutionContext *)0x1);
@@ -285,36 +309,34 @@ bool CallContext::needsOwnArguments() const
     return function->needsActivation || callData->argc < static_cast<int>(function->formalParameterCount);
 }
 
-void ExecutionContext::mark()
+void ExecutionContext::markObjects(Managed *m, ExecutionEngine *engine)
 {
-    if (marked)
-        return;
-    marked = true;
+    ExecutionContext *ctx = static_cast<ExecutionContext *>(m);
 
-    if (outer)
-        outer->mark();
+    if (ctx->outer)
+        ctx->outer->mark(engine);
 
     // ### shouldn't need these 3 lines
-    callData->thisObject.mark(engine);
-    for (int arg = 0; arg < callData->argc; ++arg)
-        callData->args[arg].mark(engine);
+    ctx->callData->thisObject.mark(engine);
+    for (int arg = 0; arg < ctx->callData->argc; ++arg)
+        ctx->callData->args[arg].mark(engine);
 
-    if (type >= Type_CallContext) {
-        QV4::CallContext *c = static_cast<CallContext *>(this);
+    if (ctx->type >= Type_CallContext) {
+        QV4::CallContext *c = static_cast<CallContext *>(ctx);
         for (unsigned local = 0, lastLocal = c->variableCount(); local < lastLocal; ++local)
             c->locals[local].mark(engine);
         if (c->activation)
             c->activation->mark(engine);
         c->function->mark(engine);
-    } else if (type == Type_WithContext) {
-        WithContext *w = static_cast<WithContext *>(this);
+    } else if (ctx->type == Type_WithContext) {
+        WithContext *w = static_cast<WithContext *>(ctx);
         w->withObject->mark(engine);
-    } else if (type == Type_CatchContext) {
-        CatchContext *c = static_cast<CatchContext *>(this);
+    } else if (ctx->type == Type_CatchContext) {
+        CatchContext *c = static_cast<CatchContext *>(ctx);
         c->exceptionVarName->mark(engine);
         c->exceptionValue.mark(engine);
-    } else if (type == Type_GlobalContext) {
-        GlobalContext *g = static_cast<GlobalContext *>(this);
+    } else if (ctx->type == Type_GlobalContext) {
+        GlobalContext *g = static_cast<GlobalContext *>(ctx);
         g->global->mark(engine);
     }
 }
diff --git a/src/qml/jsruntime/qv4context_p.h b/src/qml/jsruntime/qv4context_p.h
index ccb5cf98f8..9b080dc590 100644
--- a/src/qml/jsruntime/qv4context_p.h
+++ b/src/qml/jsruntime/qv4context_p.h
@@ -66,8 +66,21 @@ struct CallContext;
 struct CatchContext;
 struct WithContext;
 
-struct Q_QML_EXPORT ExecutionContext
+struct Q_QML_EXPORT ExecutionContext : public Managed
 {
+    Q_MANAGED
+    ExecutionContext()
+        : Managed(0) {
+        vtbl = &static_vtbl;
+    }
+    void init() {
+        _data = 0;
+        internalClass = 0;
+        inUse = 1;
+        extensible = 1;
+        vtbl = &static_vtbl;
+    }
+
     enum Type {
         Type_GlobalContext = 0x1,
         Type_CatchContext = 0x2,
@@ -79,7 +92,6 @@ struct Q_QML_EXPORT ExecutionContext
 
     Type type;
     bool strictMode;
-    bool marked;
 
     CallData *callData;
 
@@ -104,7 +116,6 @@ struct Q_QML_EXPORT ExecutionContext
     {
         this->type = type;
         strictMode = false;
-        marked = false;
         this->engine = engine;
         parent = parentContext;
         outer = 0;
@@ -148,10 +159,10 @@ struct Q_QML_EXPORT ExecutionContext
     // Can only be called from within catch(...), rethrows if no JS exception.
     ReturnedValue catchException(StackTrace *trace = 0);
 
-    void mark();
-
     inline CallContext *asCallContext();
     inline const CallContext *asCallContext() const;
+
+    static void markObjects(Managed *m, ExecutionEngine *e);
 };
 
 struct CallContext : public ExecutionContext
diff --git a/src/qml/jsruntime/qv4engine.cpp b/src/qml/jsruntime/qv4engine.cpp
index 84be89d31a..19aaee104f 100644
--- a/src/qml/jsruntime/qv4engine.cpp
+++ b/src/qml/jsruntime/qv4engine.cpp
@@ -382,7 +382,8 @@ void ExecutionEngine::enableDebugger()
 
 void ExecutionEngine::initRootContext()
 {
-    rootContext = static_cast<GlobalContext *>(memoryManager->allocContext(sizeof(GlobalContext) + sizeof(CallData)));
+    rootContext = static_cast<GlobalContext *>(memoryManager->allocManaged(sizeof(GlobalContext) + sizeof(CallData)));
+    rootContext->init();
     current = rootContext;
     current->parent = 0;
     rootContext->initGlobalContext(this);
@@ -395,9 +396,9 @@ InternalClass *ExecutionEngine::newClass(const InternalClass &other)
 
 ExecutionContext *ExecutionEngine::pushGlobalContext()
 {
-    GlobalContext *g = static_cast<GlobalContext *>(memoryManager->allocContext(sizeof(GlobalContext)));
+    GlobalContext *g = new (memoryManager) GlobalContext;
     ExecutionContext *oldNext = g->next;
-    *g = *rootContext;
+    memcpy(g, rootContext, sizeof(GlobalContext));
     g->next = oldNext;
     g->parent = current;
     current = g;
@@ -747,7 +748,7 @@ void ExecutionEngine::markObjects()
 
     ExecutionContext *c = current;
     while (c) {
-        c->mark();
+        c->mark(this);
         c = c->parent;
     }
 
diff --git a/src/qml/jsruntime/qv4engine_p.h b/src/qml/jsruntime/qv4engine_p.h
index b4972904ee..c37d4f125d 100644
--- a/src/qml/jsruntime/qv4engine_p.h
+++ b/src/qml/jsruntime/qv4engine_p.h
@@ -388,6 +388,7 @@ struct ExecutionContextSaver
 inline
 void Managed::mark(QV4::ExecutionEngine *engine)
 {
+    Q_ASSERT(inUse);
     if (markBit)
         return;
     markBit = 1;
diff --git a/src/qml/jsruntime/qv4functionobject.cpp b/src/qml/jsruntime/qv4functionobject.cpp
index 8c3131c565..99797ec56b 100644
--- a/src/qml/jsruntime/qv4functionobject.cpp
+++ b/src/qml/jsruntime/qv4functionobject.cpp
@@ -213,7 +213,7 @@ void FunctionObject::markObjects(Managed *that, ExecutionEngine *e)
 //        formalParameterList[i]->mark();
 //    for (uint i = 0; i < varCount; ++i)
 //        varList[i]->mark();
-    o->scope->mark();
+    o->scope->mark(e);
     if (o->function)
         o->function->mark(e);
 
diff --git a/src/qml/jsruntime/qv4mm.cpp b/src/qml/jsruntime/qv4mm.cpp
index d57ad69262..9cac0cf90c 100644
--- a/src/qml/jsruntime/qv4mm.cpp
+++ b/src/qml/jsruntime/qv4mm.cpp
@@ -214,7 +214,6 @@ bool operator<(const MemoryManager::Data::Chunk &a, const MemoryManager::Data::C
 
 MemoryManager::MemoryManager()
     : m_d(new Data(true))
-    , m_contextList(0)
     , m_persistentValues(0)
     , m_weakValues(0)
 {
@@ -484,20 +483,6 @@ void MemoryManager::sweep(bool lastSweep)
         i = *last;
     }
 
-    ExecutionContext *ctx = m_contextList;
-    ExecutionContext **n = &m_contextList;
-    while (ctx) {
-        ExecutionContext *next = ctx->next;
-        if (!ctx->marked) {
-            free(ctx);
-            *n = next;
-        } else {
-            ctx->marked = false;
-            n = &ctx->next;
-        }
-        ctx = next;
-    }
-
     deletable = *firstDeletable;
     while (deletable) {
         GCDeletable *next = deletable->next;
diff --git a/src/qml/jsruntime/qv4mm_p.h b/src/qml/jsruntime/qv4mm_p.h
index f3258519de..7d28319536 100644
--- a/src/qml/jsruntime/qv4mm_p.h
+++ b/src/qml/jsruntime/qv4mm_p.h
@@ -103,8 +103,6 @@ public:
         return o;
     }
 
-    ExecutionContext *allocContext(uint size);
-
     bool isGCBlocked() const;
     void setGCBlocked(bool blockGC);
     void runGC();
@@ -134,21 +132,11 @@ private:
 
 protected:
     QScopedPointer<Data> m_d;
-    ExecutionContext *m_contextList;
 public:
     PersistentValuePrivate *m_persistentValues;
     PersistentValuePrivate *m_weakValues;
 };
 
-inline ExecutionContext *MemoryManager::allocContext(uint size)
-{
-    ExecutionContext *newContext = (ExecutionContext *)malloc(size);
-    newContext->next = m_contextList;
-    m_contextList = newContext;
-    return newContext;
-}
-
-
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4script.cpp b/src/qml/jsruntime/qv4script.cpp
index 25791cff61..2f015ac83a 100644
--- a/src/qml/jsruntime/qv4script.cpp
+++ b/src/qml/jsruntime/qv4script.cpp
@@ -62,11 +62,18 @@ using namespace QV4;
 QmlBindingWrapper::QmlBindingWrapper(ExecutionContext *scope, Function *f, ObjectRef qml)
     : FunctionObject(scope, scope->engine->id_eval)
     , qml(qml)
+    , qmlContext(0)
 {
+    Q_ASSERT(scope->inUse);
+
     vtbl = &static_vtbl;
     function = f;
     function->compilationUnit->ref();
     needsActivation = function->needsActivation();
+
+    Scope s(scope);
+    ScopedValue protectThis(s, this);
+
     defineReadonlyProperty(scope->engine->id_length, Primitive::fromInt32(1));
 
     qmlContext = scope->engine->current->newQmlContext(this, qml);
@@ -76,10 +83,17 @@ QmlBindingWrapper::QmlBindingWrapper(ExecutionContext *scope, Function *f, Objec
 QmlBindingWrapper::QmlBindingWrapper(ExecutionContext *scope, ObjectRef qml)
     : FunctionObject(scope, scope->engine->id_eval)
     , qml(qml)
+    , qmlContext(0)
 {
+    Q_ASSERT(scope->inUse);
+
     vtbl = &static_vtbl;
     function = 0;
     needsActivation = false;
+
+    Scope s(scope);
+    ScopedValue protectThis(s, this);
+
     defineReadonlyProperty(scope->engine->id_length, Primitive::fromInt32(1));
 
     qmlContext = scope->engine->current->newQmlContext(this, qml);
@@ -110,7 +124,8 @@ void QmlBindingWrapper::markObjects(Managed *m, ExecutionEngine *e)
     if (wrapper->qml)
         wrapper->qml->mark(e);
     FunctionObject::markObjects(m, e);
-    wrapper->qmlContext->mark();
+    if (wrapper->qmlContext)
+        wrapper->qmlContext->mark(e);
 }
 
 DEFINE_MANAGED_VTABLE(QmlBindingWrapper);