bindings/runtime_root.cpp

   1 /*
   2  * Copyright (C) 2004 Apple Computer, Inc.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "runtime_root.h"
  28
  29 #include "JSGlobalObject.h"
  30 #include "object.h"
  31 #include "runtime.h"
  32 #include "runtime_object.h"
  33 #include <wtf/HashCountedSet.h>
  34 #include <wtf/HashSet.h>
  35
  36 namespace KJS { namespace Bindings {
  37
  38 // This code attempts to solve two problems: (1) plug-ins leaking references to
  39 // JS and the DOM; (2) plug-ins holding stale references to JS and the DOM. Previous
  40 // comments in this file claimed that problem #1 was an issue in Java, in particular,
  41 // because Java, allegedly, didn't always call finalize when collecting an object.
  42
  43 typedef HashSet<RootObject*> RootObjectSet;
  44
  45 static RootObjectSet* rootObjectSet()
  46 {
  47     static RootObjectSet staticRootObjectSet;
  48     return &staticRootObjectSet;
  49 }
  50
  51 // FIXME:  These two functions are a potential performance problem.  We could
  52 // fix them by adding a JSObject to RootObject dictionary.
  53
  54 RootObject* findProtectingRootObject(JSObject* jsObject)
  55 {
  56     RootObjectSet::const_iterator end = rootObjectSet()->end();
  57     for (RootObjectSet::const_iterator it = rootObjectSet()->begin(); it != end; ++it) {
  58         if ((*it)->gcIsProtected(jsObject))
  59             return *it;
  60     }
  61     return 0;
  62 }
  63
  64 RootObject* findRootObject(JSGlobalObject* globalObject)
  65 {
  66     RootObjectSet::const_iterator end = rootObjectSet()->end();
  67     for (RootObjectSet::const_iterator it = rootObjectSet()->begin(); it != end; ++it) {
  68         if ((*it)->globalObject() == globalObject)
  69             return *it;
  70     }
  71     return 0;
  72 }
  73
  74 // May only be set by dispatchToJavaScriptThread().
  75 #if ENABLE(JAVA_BINDINGS)
  76 static CFRunLoopSourceRef completionSource;
  77
  78 static void completedJavaScriptAccess (void *i)
  79 {
  80     assert (CFRunLoopGetCurrent() != RootObject::runLoop());
  81
  82     JSObjectCallContext *callContext = (JSObjectCallContext *)i;
  83     CFRunLoopRef runLoop = (CFRunLoopRef)callContext->originatingLoop;
  84
  85     assert (CFRunLoopGetCurrent() == runLoop);
  86
  87     CFRunLoopStop(runLoop);
  88 }
  89
  90 static pthread_once_t javaScriptAccessLockOnce = PTHREAD_ONCE_INIT;
  91 static pthread_mutex_t javaScriptAccessLock;
  92 static int javaScriptAccessLockCount = 0;
  93
  94 static void initializeJavaScriptAccessLock()
  95 {
  96     pthread_mutexattr_t attr;
  97
  98     pthread_mutexattr_init(&attr);
  99     pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE);
 100
 101     pthread_mutex_init(&javaScriptAccessLock, &attr);
 102 }
 103
 104 static inline void lockJavaScriptAccess()
 105 {
 106     // Perhaps add deadlock detection?
 107     pthread_once(&javaScriptAccessLockOnce, initializeJavaScriptAccessLock);
 108     pthread_mutex_lock(&javaScriptAccessLock);
 109     javaScriptAccessLockCount++;
 110 }
 111
 112 static inline void unlockJavaScriptAccess()
 113 {
 114     javaScriptAccessLockCount--;
 115     pthread_mutex_unlock(&javaScriptAccessLock);
 116 }
 117
 118
 119 void RootObject::dispatchToJavaScriptThread(JSObjectCallContext *context)
 120 {
 121     // This lock guarantees that only one thread can invoke
 122     // at a time, and also guarantees that completionSource;
 123     // won't get clobbered.
 124     lockJavaScriptAccess();
 125
 126     CFRunLoopRef currentRunLoop = CFRunLoopGetCurrent();
 127
 128     assert (currentRunLoop != RootObject::runLoop());
 129
 130     // Setup a source to signal once the invocation of the JavaScript
 131     // call completes.
 132     //
 133     // FIXME:  This could be a potential performance issue.  Creating and
 134     // adding run loop sources is expensive.  We could create one source
 135     // per thread, as needed, instead.
 136     context->originatingLoop = currentRunLoop;
 137     CFRunLoopSourceContext sourceContext = {0, context, NULL, NULL, NULL, NULL, NULL, NULL, NULL, completedJavaScriptAccess};
 138     completionSource = CFRunLoopSourceCreate(NULL, 0, &sourceContext);
 139     CFRunLoopAddSource(currentRunLoop, completionSource, kCFRunLoopDefaultMode);
 140
 141     // Wakeup JavaScript access thread and make it do it's work.
 142     CFRunLoopSourceSignal(RootObject::performJavaScriptSource());
 143     if (CFRunLoopIsWaiting(RootObject::runLoop())) {
 144         CFRunLoopWakeUp(RootObject::runLoop());
 145     }
 146
 147     // Wait until the JavaScript access thread is done.
 148     CFRunLoopRun ();
 149
 150     CFRunLoopRemoveSource(currentRunLoop, completionSource, kCFRunLoopDefaultMode);
 151     CFRelease (completionSource);
 152
 153     unlockJavaScriptAccess();
 154 }
 155
 156 static void performJavaScriptAccess(void*)
 157 {
 158     assert (CFRunLoopGetCurrent() == RootObject::runLoop());
 159
 160     // Dispatch JavaScript calls here.
 161     CFRunLoopSourceContext sourceContext;
 162     CFRunLoopSourceGetContext (completionSource, &sourceContext);
 163     JSObjectCallContext *callContext = (JSObjectCallContext *)sourceContext.info;
 164     CFRunLoopRef originatingLoop = callContext->originatingLoop;
 165
 166     JavaJSObject::invoke (callContext);
 167
 168     // Signal the originating thread that we're done.
 169     CFRunLoopSourceSignal (completionSource);
 170     if (CFRunLoopIsWaiting(originatingLoop)) {
 171         CFRunLoopWakeUp(originatingLoop);
 172     }
 173 }
 174 #endif // ENABLE(JAVA_BINDINGS)
 175
 176 CreateRootObjectFunction RootObject::_createRootObject = 0;
 177 CFRunLoopRef RootObject::_runLoop = 0;
 178 CFRunLoopSourceRef RootObject::_performJavaScriptSource = 0;
 179
 180 // Must be called from the thread that will be used to access JavaScript.
 181 void RootObject::setCreateRootObject(CreateRootObjectFunction createRootObject) {
 182     // Should only be called once.
 183     ASSERT(!_createRootObject);
 184
 185     _createRootObject = createRootObject;
 186
 187     // Assume that we can retain this run loop forever.  It'll most
 188     // likely (always?) be the main loop.
 189     _runLoop = (CFRunLoopRef)CFRetain (CFRunLoopGetCurrent ());
 190
 191     // Setup a source the other threads can use to signal the _runLoop
 192     // thread that a JavaScript call needs to be invoked.
 193
 194 #if ENABLE(JAVA_BINDINGS)
 195     CFRunLoopSourceContext sourceContext = {0, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, performJavaScriptAccess};
 196     RootObject::_performJavaScriptSource = CFRunLoopSourceCreate(NULL, 0, &sourceContext);
 197     CFRunLoopAddSource(RootObject::_runLoop, RootObject::_performJavaScriptSource, kCFRunLoopDefaultMode);
 198 #endif // ENABLE(JAVA_BINDINGS)
 199 }
 200
 201
 202 PassRefPtr<RootObject> RootObject::create(const void* nativeHandle, JSGlobalObject* globalObject)
 203 {
 204     return new RootObject(nativeHandle, globalObject);
 205 }
 206
 207 RootObject::RootObject(const void* nativeHandle, JSGlobalObject* globalObject)
 208     : m_isValid(true)
 209     , m_nativeHandle(nativeHandle)
 210     , m_globalObject(globalObject)
 211 {
 212     ASSERT(globalObject);
 213     rootObjectSet()->add(this);
 214 }
 215
 216 RootObject::~RootObject()
 217 {
 218     if (m_isValid)
 219         invalidate();
 220 }
 221
 222 void RootObject::invalidate()
 223 {
 224     if (!m_isValid)
 225         return;
 226
 227     {
 228         HashSet<RuntimeObjectImp*>::iterator end = m_runtimeObjects.end();
 229         for (HashSet<RuntimeObjectImp*>::iterator it = m_runtimeObjects.begin(); it != end; ++it)
 230             (*it)->invalidate();
 231
 232         m_runtimeObjects.clear();
 233     }
 234
 235     m_isValid = false;
 236
 237     m_nativeHandle = 0;
 238     m_globalObject = 0;
 239
 240     ProtectCountSet::iterator end = m_protectCountSet.end();
 241     for (ProtectCountSet::iterator it = m_protectCountSet.begin(); it != end; ++it) {
 242         JSLock lock;
 243         KJS::gcUnprotect(it->first);
 244     }
 245     m_protectCountSet.clear();
 246
 247     rootObjectSet()->remove(this);
 248 }
 249
 250 void RootObject::gcProtect(JSObject* jsObject)
 251 {
 252     ASSERT(m_isValid);
 253
 254     if (!m_protectCountSet.contains(jsObject)) {
 255         JSLock lock;
 256         KJS::gcProtect(jsObject);
 257     }
 258     m_protectCountSet.add(jsObject);
 259 }
 260
 261 void RootObject::gcUnprotect(JSObject* jsObject)
 262 {
 263     ASSERT(m_isValid);
 264
 265     if (!jsObject)
 266         return;
 267
 268     if (m_protectCountSet.count(jsObject) == 1) {
 269         JSLock lock;
 270         KJS::gcUnprotect(jsObject);
 271     }
 272     m_protectCountSet.remove(jsObject);
 273 }
 274
 275 bool RootObject::gcIsProtected(JSObject* jsObject)
 276 {
 277     ASSERT(m_isValid);
 278     return m_protectCountSet.contains(jsObject);
 279 }
 280
 281 const void* RootObject::nativeHandle() const
 282 {
 283     ASSERT(m_isValid);
 284     return m_nativeHandle;
 285 }
 286
 287 JSGlobalObject* RootObject::globalObject() const
 288 {
 289     ASSERT(m_isValid);
 290     return m_globalObject;
 291 }
 292
 293 void RootObject::addRuntimeObject(RuntimeObjectImp* object)
 294 {
 295     ASSERT(m_isValid);
 296     ASSERT(!m_runtimeObjects.contains(object));
 297
 298     m_runtimeObjects.add(object);
 299 }
 300
 301 void RootObject::removeRuntimeObject(RuntimeObjectImp* object)
 302 {
 303     ASSERT(m_isValid);
 304     ASSERT(m_runtimeObjects.contains(object));
 305
 306     m_runtimeObjects.remove(object);
 307 }
 308
 309 } } // namespace KJS::Bindings