JavaScriptCore/bindings/runtime_root.cpp - third_party/webkit - Git at Google

 /*
  * Copyright (C) 2004 Apple Computer, 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 COMPUTER, INC. ``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 COMPUTER, INC. OR
  * 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 "runtime_root.h"

 #include "JSGlobalObject.h"
 #include "object.h"
 #include "runtime.h"
 #include "runtime_object.h"
 #include <wtf/HashCountedSet.h>
 #include <wtf/HashSet.h>

 namespace KJS { namespace Bindings {

 // This code attempts to solve two problems: (1) plug-ins leaking references to
 // JS and the DOM; (2) plug-ins holding stale references to JS and the DOM. Previous
 // comments in this file claimed that problem #1 was an issue in Java, in particular,
 // because Java, allegedly, didn't always call finalize when collecting an object.

 typedef HashSet<RootObject*> RootObjectSet;

 static RootObjectSet* rootObjectSet()
 {
     static RootObjectSet staticRootObjectSet;
     return &staticRootObjectSet;
 }

 // FIXME:  These two functions are a potential performance problem.  We could
 // fix them by adding a JSObject to RootObject dictionary.

 RootObject* findProtectingRootObject(JSObject* jsObject)
 {
     RootObjectSet::const_iterator end = rootObjectSet()->end();
     for (RootObjectSet::const_iterator it = rootObjectSet()->begin(); it != end; ++it) {
         if ((*it)->gcIsProtected(jsObject))
             return *it;
     }
     return 0;
 }

 RootObject* findRootObject(JSGlobalObject* globalObject)
 {
     RootObjectSet::const_iterator end = rootObjectSet()->end();
     for (RootObjectSet::const_iterator it = rootObjectSet()->begin(); it != end; ++it) {
         if ((*it)->globalObject() == globalObject)
             return *it;
     }
     return 0;
 }

 #if PLATFORM(MAC)
 // May only be set by dispatchToJavaScriptThread().
 static CFRunLoopSourceRef completionSource;

 static void completedJavaScriptAccess (void *i)
 {
     assert (CFRunLoopGetCurrent() != RootObject::runLoop());

     JSObjectCallContext *callContext = (JSObjectCallContext *)i;
     CFRunLoopRef runLoop = (CFRunLoopRef)callContext->originatingLoop;

     assert (CFRunLoopGetCurrent() == runLoop);

     CFRunLoopStop(runLoop);
 }

 static pthread_once_t javaScriptAccessLockOnce = PTHREAD_ONCE_INIT;
 static pthread_mutex_t javaScriptAccessLock;
 static int javaScriptAccessLockCount = 0;

 static void initializeJavaScriptAccessLock()
 {
     pthread_mutexattr_t attr;

     pthread_mutexattr_init(&attr);
     pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE);

     pthread_mutex_init(&javaScriptAccessLock, &attr);
 }

 static inline void lockJavaScriptAccess()
 {
     // Perhaps add deadlock detection?
     pthread_once(&javaScriptAccessLockOnce, initializeJavaScriptAccessLock);
     pthread_mutex_lock(&javaScriptAccessLock);
     javaScriptAccessLockCount++;
 }

 static inline void unlockJavaScriptAccess()
 {
     javaScriptAccessLockCount--;
     pthread_mutex_unlock(&javaScriptAccessLock);
 }


 void RootObject::dispatchToJavaScriptThread(JSObjectCallContext *context)
 {
     // This lock guarantees that only one thread can invoke
     // at a time, and also guarantees that completionSource;
     // won't get clobbered.
     lockJavaScriptAccess();

     CFRunLoopRef currentRunLoop = CFRunLoopGetCurrent();

     assert (currentRunLoop != RootObject::runLoop());

     // Setup a source to signal once the invocation of the JavaScript
     // call completes.
     //
     // FIXME:  This could be a potential performance issue.  Creating and
     // adding run loop sources is expensive.  We could create one source
     // per thread, as needed, instead.
     context->originatingLoop = currentRunLoop;
     CFRunLoopSourceContext sourceContext = {0, context, NULL, NULL, NULL, NULL, NULL, NULL, NULL, completedJavaScriptAccess};
     completionSource = CFRunLoopSourceCreate(NULL, 0, &sourceContext);
     CFRunLoopAddSource(currentRunLoop, completionSource, kCFRunLoopDefaultMode);

     // Wakeup JavaScript access thread and make it do it's work.
     CFRunLoopSourceSignal(RootObject::performJavaScriptSource());
     if (CFRunLoopIsWaiting(RootObject::runLoop())) {
         CFRunLoopWakeUp(RootObject::runLoop());
     }

     // Wait until the JavaScript access thread is done.
     CFRunLoopRun ();

     CFRunLoopRemoveSource(currentRunLoop, completionSource, kCFRunLoopDefaultMode);
     CFRelease (completionSource);

     unlockJavaScriptAccess();
 }

 static void performJavaScriptAccess(void*)
 {
     assert (CFRunLoopGetCurrent() == RootObject::runLoop());

     // Dispatch JavaScript calls here.
     CFRunLoopSourceContext sourceContext;
     CFRunLoopSourceGetContext (completionSource, &sourceContext);
     JSObjectCallContext *callContext = (JSObjectCallContext *)sourceContext.info;
     CFRunLoopRef originatingLoop = callContext->originatingLoop;

     JavaJSObject::invoke (callContext);

     // Signal the originating thread that we're done.
     CFRunLoopSourceSignal (completionSource);
     if (CFRunLoopIsWaiting(originatingLoop)) {
         CFRunLoopWakeUp(originatingLoop);
     }
 }

 CreateRootObjectFunction RootObject::_createRootObject = 0;
 CFRunLoopRef RootObject::_runLoop = 0;
 CFRunLoopSourceRef RootObject::_performJavaScriptSource = 0;

 // Must be called from the thread that will be used to access JavaScript.
 void RootObject::setCreateRootObject(CreateRootObjectFunction createRootObject) {
     // Should only be called once.
     ASSERT(!_createRootObject);

     _createRootObject = createRootObject;

     // Assume that we can retain this run loop forever.  It'll most
     // likely (always?) be the main loop.
     _runLoop = (CFRunLoopRef)CFRetain (CFRunLoopGetCurrent ());

     // Setup a source the other threads can use to signal the _runLoop
     // thread that a JavaScript call needs to be invoked.
     CFRunLoopSourceContext sourceContext = {0, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, performJavaScriptAccess};
     RootObject::_performJavaScriptSource = CFRunLoopSourceCreate(NULL, 0, &sourceContext);
     CFRunLoopAddSource(RootObject::_runLoop, RootObject::_performJavaScriptSource, kCFRunLoopDefaultMode);
 }

 #endif

 PassRefPtr<RootObject> RootObject::create(const void* nativeHandle, JSGlobalObject* globalObject)
 {
     return new RootObject(nativeHandle, globalObject);
 }

 RootObject::RootObject(const void* nativeHandle, JSGlobalObject* globalObject)
     : m_isValid(true)
     , m_nativeHandle(nativeHandle)
     , m_globalObject(globalObject)
 {
     ASSERT(globalObject);
     rootObjectSet()->add(this);
 }

 RootObject::~RootObject()
 {
     if (m_isValid)
         invalidate();
 }

 void RootObject::invalidate()
 {
     if (!m_isValid)
         return;

     {
         HashSet<RuntimeObjectImp*>::iterator end = m_runtimeObjects.end();
         for (HashSet<RuntimeObjectImp*>::iterator it = m_runtimeObjects.begin(); it != end; ++it)
             (*it)->invalidate();

         m_runtimeObjects.clear();
     }

     m_isValid = false;

     m_nativeHandle = 0;
     m_globalObject = 0;

     ProtectCountSet::iterator end = m_protectCountSet.end();
     for (ProtectCountSet::iterator it = m_protectCountSet.begin(); it != end; ++it) {
         JSLock lock;
         KJS::gcUnprotect(it->first);
     }
     m_protectCountSet.clear();

     rootObjectSet()->remove(this);
 }

 void RootObject::gcProtect(JSObject* jsObject)
 {
     ASSERT(m_isValid);

     if (!m_protectCountSet.contains(jsObject)) {
         JSLock lock;
         KJS::gcProtect(jsObject);
     }
     m_protectCountSet.add(jsObject);
 }

 void RootObject::gcUnprotect(JSObject* jsObject)
 {
     ASSERT(m_isValid);

     if (!jsObject)
         return;

     if (m_protectCountSet.count(jsObject) == 1) {
         JSLock lock;
         KJS::gcUnprotect(jsObject);
     }
     m_protectCountSet.remove(jsObject);
 }

 bool RootObject::gcIsProtected(JSObject* jsObject)
 {
     ASSERT(m_isValid);
     return m_protectCountSet.contains(jsObject);
 }

 const void* RootObject::nativeHandle() const
 {
     ASSERT(m_isValid);
     return m_nativeHandle;
 }

 JSGlobalObject* RootObject::globalObject() const
 {
     ASSERT(m_isValid);
     return m_globalObject;
 }

 void RootObject::addRuntimeObject(RuntimeObjectImp* object)
 {
     ASSERT(m_isValid);
     ASSERT(!m_runtimeObjects.contains(object));

     m_runtimeObjects.add(object);
 }

 void RootObject::removeRuntimeObject(RuntimeObjectImp* object)
 {
     ASSERT(m_isValid);
     ASSERT(m_runtimeObjects.contains(object));

     m_runtimeObjects.remove(object);
 }

 } } // namespace KJS::Bindings
	/*
	* Copyright (C) 2004 Apple Computer, 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 COMPUTER, INC. ``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 COMPUTER, INC. OR
	* 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 "runtime_root.h"

	#include "JSGlobalObject.h"
	#include "object.h"
	#include "runtime.h"
	#include "runtime_object.h"
	#include <wtf/HashCountedSet.h>
	#include <wtf/HashSet.h>

	namespace KJS { namespace Bindings {

	// This code attempts to solve two problems: (1) plug-ins leaking references to
	// JS and the DOM; (2) plug-ins holding stale references to JS and the DOM. Previous
	// comments in this file claimed that problem #1 was an issue in Java, in particular,
	// because Java, allegedly, didn't always call finalize when collecting an object.

	typedef HashSet<RootObject*> RootObjectSet;

	static RootObjectSet* rootObjectSet()
	{
	static RootObjectSet staticRootObjectSet;
	return &staticRootObjectSet;
	}

	// FIXME: These two functions are a potential performance problem. We could
	// fix them by adding a JSObject to RootObject dictionary.

	RootObject* findProtectingRootObject(JSObject* jsObject)
	{
	RootObjectSet::const_iterator end = rootObjectSet()->end();
	for (RootObjectSet::const_iterator it = rootObjectSet()->begin(); it != end; ++it) {
	if ((*it)->gcIsProtected(jsObject))
	return *it;
	}
	return 0;
	}

	RootObject* findRootObject(JSGlobalObject* globalObject)
	{
	RootObjectSet::const_iterator end = rootObjectSet()->end();
	for (RootObjectSet::const_iterator it = rootObjectSet()->begin(); it != end; ++it) {
	if ((*it)->globalObject() == globalObject)
	return *it;
	}
	return 0;
	}

	#if PLATFORM(MAC)
	// May only be set by dispatchToJavaScriptThread().
	static CFRunLoopSourceRef completionSource;

	static void completedJavaScriptAccess (void *i)
	{
	assert (CFRunLoopGetCurrent() != RootObject::runLoop());

	JSObjectCallContext callContext = (JSObjectCallContext )i;
	CFRunLoopRef runLoop = (CFRunLoopRef)callContext->originatingLoop;

	assert (CFRunLoopGetCurrent() == runLoop);

	CFRunLoopStop(runLoop);
	}

	static pthread_once_t javaScriptAccessLockOnce = PTHREAD_ONCE_INIT;
	static pthread_mutex_t javaScriptAccessLock;
	static int javaScriptAccessLockCount = 0;

	static void initializeJavaScriptAccessLock()
	{
	pthread_mutexattr_t attr;

	pthread_mutexattr_init(&attr);
	pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE);

	pthread_mutex_init(&javaScriptAccessLock, &attr);
	}

	static inline void lockJavaScriptAccess()
	{
	// Perhaps add deadlock detection?
	pthread_once(&javaScriptAccessLockOnce, initializeJavaScriptAccessLock);
	pthread_mutex_lock(&javaScriptAccessLock);
	javaScriptAccessLockCount++;
	}

	static inline void unlockJavaScriptAccess()
	{
	javaScriptAccessLockCount--;
	pthread_mutex_unlock(&javaScriptAccessLock);
	}


	void RootObject::dispatchToJavaScriptThread(JSObjectCallContext *context)
	{
	// This lock guarantees that only one thread can invoke
	// at a time, and also guarantees that completionSource;
	// won't get clobbered.
	lockJavaScriptAccess();

	CFRunLoopRef currentRunLoop = CFRunLoopGetCurrent();

	assert (currentRunLoop != RootObject::runLoop());

	// Setup a source to signal once the invocation of the JavaScript
	// call completes.
	//
	// FIXME: This could be a potential performance issue. Creating and
	// adding run loop sources is expensive. We could create one source
	// per thread, as needed, instead.
	context->originatingLoop = currentRunLoop;
	CFRunLoopSourceContext sourceContext = {0, context, NULL, NULL, NULL, NULL, NULL, NULL, NULL, completedJavaScriptAccess};
	completionSource = CFRunLoopSourceCreate(NULL, 0, &sourceContext);
	CFRunLoopAddSource(currentRunLoop, completionSource, kCFRunLoopDefaultMode);

	// Wakeup JavaScript access thread and make it do it's work.
	CFRunLoopSourceSignal(RootObject::performJavaScriptSource());
	if (CFRunLoopIsWaiting(RootObject::runLoop())) {
	CFRunLoopWakeUp(RootObject::runLoop());
	}

	// Wait until the JavaScript access thread is done.
	CFRunLoopRun ();

	CFRunLoopRemoveSource(currentRunLoop, completionSource, kCFRunLoopDefaultMode);
	CFRelease (completionSource);

	unlockJavaScriptAccess();
	}

	static void performJavaScriptAccess(void*)
	{
	assert (CFRunLoopGetCurrent() == RootObject::runLoop());

	// Dispatch JavaScript calls here.
	CFRunLoopSourceContext sourceContext;
	CFRunLoopSourceGetContext (completionSource, &sourceContext);
	JSObjectCallContext callContext = (JSObjectCallContext )sourceContext.info;
	CFRunLoopRef originatingLoop = callContext->originatingLoop;

	JavaJSObject::invoke (callContext);

	// Signal the originating thread that we're done.
	CFRunLoopSourceSignal (completionSource);
	if (CFRunLoopIsWaiting(originatingLoop)) {
	CFRunLoopWakeUp(originatingLoop);
	}
	}

	CreateRootObjectFunction RootObject::_createRootObject = 0;
	CFRunLoopRef RootObject::_runLoop = 0;
	CFRunLoopSourceRef RootObject::_performJavaScriptSource = 0;

	// Must be called from the thread that will be used to access JavaScript.
	void RootObject::setCreateRootObject(CreateRootObjectFunction createRootObject) {
	// Should only be called once.
	ASSERT(!_createRootObject);

	_createRootObject = createRootObject;

	// Assume that we can retain this run loop forever. It'll most
	// likely (always?) be the main loop.
	_runLoop = (CFRunLoopRef)CFRetain (CFRunLoopGetCurrent ());

	// Setup a source the other threads can use to signal the _runLoop
	// thread that a JavaScript call needs to be invoked.
	CFRunLoopSourceContext sourceContext = {0, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, performJavaScriptAccess};
	RootObject::_performJavaScriptSource = CFRunLoopSourceCreate(NULL, 0, &sourceContext);
	CFRunLoopAddSource(RootObject::_runLoop, RootObject::_performJavaScriptSource, kCFRunLoopDefaultMode);
	}

	#endif

	PassRefPtr<RootObject> RootObject::create(const void* nativeHandle, JSGlobalObject* globalObject)
	{
	return new RootObject(nativeHandle, globalObject);
	}

	RootObject::RootObject(const void* nativeHandle, JSGlobalObject* globalObject)
	: m_isValid(true)
	, m_nativeHandle(nativeHandle)
	, m_globalObject(globalObject)
	{
	ASSERT(globalObject);
	rootObjectSet()->add(this);
	}

	RootObject::~RootObject()
	{
	if (m_isValid)
	invalidate();
	}

	void RootObject::invalidate()
	{
	if (!m_isValid)
	return;

	{
	HashSet<RuntimeObjectImp*>::iterator end = m_runtimeObjects.end();
	for (HashSet<RuntimeObjectImp*>::iterator it = m_runtimeObjects.begin(); it != end; ++it)
	(*it)->invalidate();

	m_runtimeObjects.clear();
	}

	m_isValid = false;

	m_nativeHandle = 0;
	m_globalObject = 0;

	ProtectCountSet::iterator end = m_protectCountSet.end();
	for (ProtectCountSet::iterator it = m_protectCountSet.begin(); it != end; ++it) {
	JSLock lock;
	KJS::gcUnprotect(it->first);
	}
	m_protectCountSet.clear();

	rootObjectSet()->remove(this);
	}

	void RootObject::gcProtect(JSObject* jsObject)
	{
	ASSERT(m_isValid);

	if (!m_protectCountSet.contains(jsObject)) {
	JSLock lock;
	KJS::gcProtect(jsObject);
	}
	m_protectCountSet.add(jsObject);
	}

	void RootObject::gcUnprotect(JSObject* jsObject)
	{
	ASSERT(m_isValid);

	if (!jsObject)
	return;

	if (m_protectCountSet.count(jsObject) == 1) {
	JSLock lock;
	KJS::gcUnprotect(jsObject);
	}
	m_protectCountSet.remove(jsObject);
	}

	bool RootObject::gcIsProtected(JSObject* jsObject)
	{
	ASSERT(m_isValid);
	return m_protectCountSet.contains(jsObject);
	}

	const void* RootObject::nativeHandle() const
	{
	ASSERT(m_isValid);
	return m_nativeHandle;
	}

	JSGlobalObject* RootObject::globalObject() const
	{
	ASSERT(m_isValid);
	return m_globalObject;
	}

	void RootObject::addRuntimeObject(RuntimeObjectImp* object)
	{
	ASSERT(m_isValid);
	ASSERT(!m_runtimeObjects.contains(object));

	m_runtimeObjects.add(object);
	}

	void RootObject::removeRuntimeObject(RuntimeObjectImp* object)
	{
	ASSERT(m_isValid);
	ASSERT(m_runtimeObjects.contains(object));

	m_runtimeObjects.remove(object);
	}

	} } // namespace KJS::Bindings