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/*
* Copyright (C) 2008 Apple 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 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 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 "WorkerThread.h"
#include "ContentSecurityPolicyResponseHeaders.h"
#include "DedicatedWorkerGlobalScope.h"
#include "ScriptSourceCode.h"
#include "SecurityOrigin.h"
#include "ThreadGlobalData.h"
#include "URL.h"
#include <utility>
#include <wtf/Lock.h>
#include <wtf/NeverDestroyed.h>
#include <wtf/Noncopyable.h>
#include <wtf/text/WTFString.h>
#if PLATFORM(IOS)
#include "FloatingPointEnvironment.h"
#include "WebCoreThread.h"
#endif
#if PLATFORM(GTK)
#include <wtf/glib/GRefPtr.h>
#endif
namespace WebCore {
static StaticLock threadSetMutex;
static HashSet<WorkerThread*>& workerThreads()
{
static NeverDestroyed<HashSet<WorkerThread*>> workerThreads;
return workerThreads;
}
unsigned WorkerThread::workerThreadCount()
{
std::lock_guard<StaticLock> lock(threadSetMutex);
return workerThreads().size();
}
struct WorkerThreadStartupData {
WTF_MAKE_NONCOPYABLE(WorkerThreadStartupData); WTF_MAKE_FAST_ALLOCATED;
public:
WorkerThreadStartupData(const URL& scriptURL, const String& userAgent, const String& sourceCode, WorkerThreadStartMode, const ContentSecurityPolicyResponseHeaders&, bool shouldBypassMainWorldContentSecurityPolicy, const SecurityOrigin* topOrigin);
URL m_scriptURL;
String m_userAgent;
String m_sourceCode;
WorkerThreadStartMode m_startMode;
ContentSecurityPolicyResponseHeaders m_contentSecurityPolicyResponseHeaders;
bool m_shouldBypassMainWorldContentSecurityPolicy;
RefPtr<SecurityOrigin> m_topOrigin;
};
WorkerThreadStartupData::WorkerThreadStartupData(const URL& scriptURL, const String& userAgent, const String& sourceCode, WorkerThreadStartMode startMode, const ContentSecurityPolicyResponseHeaders& contentSecurityPolicyResponseHeaders, bool shouldBypassMainWorldContentSecurityPolicy, const SecurityOrigin* topOrigin)
: m_scriptURL(scriptURL.isolatedCopy())
, m_userAgent(userAgent.isolatedCopy())
, m_sourceCode(sourceCode.isolatedCopy())
, m_startMode(startMode)
, m_contentSecurityPolicyResponseHeaders(contentSecurityPolicyResponseHeaders.isolatedCopy())
, m_shouldBypassMainWorldContentSecurityPolicy(shouldBypassMainWorldContentSecurityPolicy)
, m_topOrigin(topOrigin ? &topOrigin->isolatedCopy().get() : nullptr)
{
}
WorkerThread::WorkerThread(const URL& scriptURL, const String& userAgent, const String& sourceCode, WorkerLoaderProxy& workerLoaderProxy, WorkerReportingProxy& workerReportingProxy, WorkerThreadStartMode startMode, const ContentSecurityPolicyResponseHeaders& contentSecurityPolicyResponseHeaders, bool shouldBypassMainWorldContentSecurityPolicy, const SecurityOrigin* topOrigin)
: m_threadID(0)
, m_workerLoaderProxy(workerLoaderProxy)
, m_workerReportingProxy(workerReportingProxy)
, m_startupData(std::make_unique<WorkerThreadStartupData>(scriptURL, userAgent, sourceCode, startMode, contentSecurityPolicyResponseHeaders, shouldBypassMainWorldContentSecurityPolicy, topOrigin))
#if ENABLE(NOTIFICATIONS) || ENABLE(LEGACY_NOTIFICATIONS)
, m_notificationClient(0)
#endif
{
std::lock_guard<StaticLock> lock(threadSetMutex);
workerThreads().add(this);
}
WorkerThread::~WorkerThread()
{
std::lock_guard<StaticLock> lock(threadSetMutex);
ASSERT(workerThreads().contains(this));
workerThreads().remove(this);
}
bool WorkerThread::start()
{
// Mutex protection is necessary to ensure that m_threadID is initialized when the thread starts.
LockHolder lock(m_threadCreationMutex);
if (m_threadID)
return true;
m_threadID = createThread(WorkerThread::workerThreadStart, this, "WebCore: Worker");
return m_threadID;
}
void WorkerThread::workerThreadStart(void* thread)
{
static_cast<WorkerThread*>(thread)->workerThread();
}
void WorkerThread::workerThread()
{
// Propagate the mainThread's fenv to workers.
#if PLATFORM(IOS)
FloatingPointEnvironment::singleton().propagateMainThreadEnvironment();
#endif
#if PLATFORM(GTK)
GRefPtr<GMainContext> mainContext = adoptGRef(g_main_context_new());
g_main_context_push_thread_default(mainContext.get());
#endif
{
LockHolder lock(m_threadCreationMutex);
m_workerGlobalScope = createWorkerGlobalScope(m_startupData->m_scriptURL, m_startupData->m_userAgent, m_startupData->m_contentSecurityPolicyResponseHeaders, m_startupData->m_shouldBypassMainWorldContentSecurityPolicy, m_startupData->m_topOrigin.release());
if (m_runLoop.terminated()) {
// The worker was terminated before the thread had a chance to run. Since the context didn't exist yet,
// forbidExecution() couldn't be called from stop().
m_workerGlobalScope->script()->forbidExecution();
}
}
WorkerScriptController* script = m_workerGlobalScope->script();
script->evaluate(ScriptSourceCode(m_startupData->m_sourceCode, m_startupData->m_scriptURL));
// Free the startup data to cause its member variable deref's happen on the worker's thread (since
// all ref/derefs of these objects are happening on the thread at this point). Note that
// WorkerThread::~WorkerThread happens on a different thread where it was created.
m_startupData = nullptr;
runEventLoop();
#if PLATFORM(GTK)
g_main_context_pop_thread_default(mainContext.get());
#endif
ThreadIdentifier threadID = m_threadID;
ASSERT(m_workerGlobalScope->hasOneRef());
// The below assignment will destroy the context, which will in turn notify messaging proxy.
// We cannot let any objects survive past thread exit, because no other thread will run GC or otherwise destroy them.
m_workerGlobalScope = nullptr;
// Clean up WebCore::ThreadGlobalData before WTF::WTFThreadData goes away!
threadGlobalData().destroy();
// The thread object may be already destroyed from notification now, don't try to access "this".
detachThread(threadID);
}
void WorkerThread::runEventLoop()
{
// Does not return until terminated.
m_runLoop.run(m_workerGlobalScope.get());
}
void WorkerThread::stop()
{
// Mutex protection is necessary because stop() can be called before the context is fully created.
LockHolder lock(m_threadCreationMutex);
// Ensure that tasks are being handled by thread event loop. If script execution weren't forbidden, a while(1) loop in JS could keep the thread alive forever.
if (m_workerGlobalScope) {
m_workerGlobalScope->script()->scheduleExecutionTermination();
m_runLoop.postTaskAndTerminate({ ScriptExecutionContext::Task::CleanupTask, [] (ScriptExecutionContext& context ) {
WorkerGlobalScope& workerGlobalScope = downcast<WorkerGlobalScope>(context);
workerGlobalScope.stopActiveDOMObjects();
workerGlobalScope.notifyObserversOfStop();
// Event listeners would keep DOMWrapperWorld objects alive for too long. Also, they have references to JS objects,
// which become dangling once Heap is destroyed.
workerGlobalScope.removeAllEventListeners();
// Stick a shutdown command at the end of the queue, so that we deal
// with all the cleanup tasks the databases post first.
workerGlobalScope.postTask({ ScriptExecutionContext::Task::CleanupTask, [] (ScriptExecutionContext& context) {
WorkerGlobalScope& workerGlobalScope = downcast<WorkerGlobalScope>(context);
// It's not safe to call clearScript until all the cleanup tasks posted by functions initiated by WorkerThreadShutdownStartTask have completed.
workerGlobalScope.clearScript();
} });
} });
return;
}
m_runLoop.terminate();
}
void WorkerThread::releaseFastMallocFreeMemoryInAllThreads()
{
std::lock_guard<StaticLock> lock(threadSetMutex);
for (auto* workerThread : workerThreads()) {
workerThread->runLoop().postTask([] (ScriptExecutionContext&) {
WTF::releaseFastMallocFreeMemory();
});
}
}
} // namespace WebCore
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