external/webkit r30707

1 files changed, 305 insertions, 0 deletions

diff --git a/JavaScriptCore/bindings/runtime_root.cpp b/JavaScriptCore/bindings/runtime_root.cpp
new file mode 100644
index 0000000..e7ae28f
--- /dev/null
+++ b/JavaScriptCore/bindings/runtime_root.cpp
@@ -0,0 +1,305 @@
+/*
+ * 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 adoptRef(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