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/*
* Copyright (C) 2008-2017 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 "IDBConnectionProxy.h"
#include "ScriptSourceCode.h"
#include "SecurityOrigin.h"
#include "SocketProvider.h"
#include "ThreadGlobalData.h"
#include "WorkerGlobalScope.h"
#include "WorkerInspectorController.h"
#include <utility>
#include <wtf/Lock.h>
#include <wtf/NeverDestroyed.h>
#include <wtf/Noncopyable.h>
#include <wtf/text/WTFString.h>
#if PLATFORM(IOS_FAMILY)
#include "FloatingPointEnvironment.h"
#include "WebCoreThread.h"
#endif
#if USE(GLIB)
#include <wtf/glib/GRefPtr.h>
#endif
namespace WebCore {
HashSet<WorkerThread*>& WorkerThread::workerThreads(const LockHolder&)
{
static NeverDestroyed<HashSet<WorkerThread*>> workerThreads;
return workerThreads;
}
Lock& WorkerThread::workerThreadsMutex()
{
static Lock mutex;
return mutex;
}
unsigned WorkerThread::workerThreadCount()
{
LockHolder lock(workerThreadsMutex());
return workerThreads(lock).size();
}
WorkerParameters WorkerParameters::isolatedCopy() const
{
return {
scriptURL.isolatedCopy(),
name.isolatedCopy(),
identifier.isolatedCopy(),
userAgent.isolatedCopy(),
isOnline,
contentSecurityPolicyResponseHeaders,
shouldBypassMainWorldContentSecurityPolicy,
timeOrigin,
referrerPolicy,
requestAnimationFrameEnabled,
};
}
struct WorkerThreadStartupData {
WTF_MAKE_NONCOPYABLE(WorkerThreadStartupData); WTF_MAKE_FAST_ALLOCATED;
public:
WorkerThreadStartupData(const WorkerParameters& params, const String& sourceCode, WorkerThreadStartMode, const SecurityOrigin& topOrigin);
WorkerParameters params;
Ref<SecurityOrigin> origin;
String sourceCode;
WorkerThreadStartMode startMode;
Ref<SecurityOrigin> topOrigin;
};
WorkerThreadStartupData::WorkerThreadStartupData(const WorkerParameters& other, const String& sourceCode, WorkerThreadStartMode startMode, const SecurityOrigin& topOrigin)
: params(other.isolatedCopy())
, origin(SecurityOrigin::create(other.scriptURL)->isolatedCopy())
, sourceCode(sourceCode.isolatedCopy())
, startMode(startMode)
, topOrigin(topOrigin.isolatedCopy())
{
}
WorkerThread::WorkerThread(const WorkerParameters& params, const String& sourceCode, WorkerLoaderProxy& workerLoaderProxy, WorkerDebuggerProxy& workerDebuggerProxy, WorkerReportingProxy& workerReportingProxy, WorkerThreadStartMode startMode, const SecurityOrigin& topOrigin, IDBClient::IDBConnectionProxy* connectionProxy, SocketProvider* socketProvider, JSC::RuntimeFlags runtimeFlags)
: m_identifier(params.identifier.isolatedCopy())
, m_workerLoaderProxy(workerLoaderProxy)
, m_workerDebuggerProxy(workerDebuggerProxy)
, m_workerReportingProxy(workerReportingProxy)
, m_runtimeFlags(runtimeFlags)
, m_startupData(makeUnique<WorkerThreadStartupData>(params, sourceCode, startMode, topOrigin))
#if ENABLE(INDEXED_DATABASE)
, m_idbConnectionProxy(connectionProxy)
#endif
, m_socketProvider(socketProvider)
{
#if !ENABLE(INDEXED_DATABASE)
UNUSED_PARAM(connectionProxy);
#endif
LockHolder lock(workerThreadsMutex());
workerThreads(lock).add(this);
}
WorkerThread::~WorkerThread()
{
LockHolder lock(workerThreadsMutex());
ASSERT(workerThreads(lock).contains(this));
workerThreads(lock).remove(this);
}
void WorkerThread::start(WTF::Function<void(const String&)>&& evaluateCallback)
{
// Mutex protection is necessary to ensure that m_thread is initialized when the thread starts.
LockHolder lock(m_threadCreationAndWorkerGlobalScopeMutex);
if (m_thread)
return;
m_evaluateCallback = WTFMove(evaluateCallback);
Ref<Thread> thread = Thread::create(isServiceWorkerThread() ? "WebCore: Service Worker" : "WebCore: Worker", [this] {
workerThread();
}, ThreadType::JavaScript);
// Force the Thread object to be initialized fully before storing it to m_thread (and becoming visible to other threads).
WTF::storeStoreFence();
m_thread = WTFMove(thread);
}
void WorkerThread::workerThread()
{
auto protectedThis = makeRef(*this);
// Propagate the mainThread's fenv to workers.
#if PLATFORM(IOS_FAMILY)
FloatingPointEnvironment::singleton().propagateMainThreadEnvironment();
#endif
#if USE(GLIB)
GRefPtr<GMainContext> mainContext = adoptGRef(g_main_context_new());
g_main_context_push_thread_default(mainContext.get());
#endif
WorkerScriptController* scriptController;
{
// Mutex protection is necessary to ensure that we don't change m_workerGlobalScope
// while WorkerThread::stop() is accessing it. Note that WorkerThread::stop() can
// be called before we've finished creating the WorkerGlobalScope.
LockHolder lock(m_threadCreationAndWorkerGlobalScopeMutex);
m_workerGlobalScope = createWorkerGlobalScope(m_startupData->params, WTFMove(m_startupData->origin), WTFMove(m_startupData->topOrigin));
scriptController = m_workerGlobalScope->script();
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().
scriptController->scheduleExecutionTermination();
scriptController->forbidExecution();
}
}
if (m_startupData->startMode == WorkerThreadStartMode::WaitForInspector) {
startRunningDebuggerTasks();
// If the worker was somehow terminated while processing debugger commands.
if (m_runLoop.terminated())
scriptController->forbidExecution();
}
String exceptionMessage;
scriptController->evaluate(ScriptSourceCode(m_startupData->sourceCode, URL(m_startupData->params.scriptURL)), &exceptionMessage);
finishedEvaluatingScript();
callOnMainThread([evaluateCallback = WTFMove(m_evaluateCallback), message = exceptionMessage.isolatedCopy()] {
if (evaluateCallback)
evaluateCallback(message);
});
// 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 USE(GLIB)
g_main_context_pop_thread_default(mainContext.get());
#endif
RefPtr<Thread> protector = m_thread;
ASSERT(m_workerGlobalScope->hasOneRef());
RefPtr<WorkerGlobalScope> workerGlobalScopeToDelete;
{
// Mutex protection is necessary to ensure that we don't change m_workerGlobalScope
// while WorkerThread::stop is accessing it.
LockHolder lock(m_threadCreationAndWorkerGlobalScopeMutex);
// Delay the destruction of the WorkerGlobalScope context until after we've unlocked the
// m_threadCreationAndWorkerGlobalScopeMutex. This is needed because destructing the
// context will trigger the main thread to race against us to delete the WorkerThread
// object, and the WorkerThread object owns the mutex we need to unlock after this.
workerGlobalScopeToDelete = WTFMove(m_workerGlobalScope);
if (m_stoppedCallback)
callOnMainThread(WTFMove(m_stoppedCallback));
}
// 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.
workerGlobalScopeToDelete = nullptr;
// Clean up WebCore::ThreadGlobalData before WTF::Thread goes away!
threadGlobalData().destroy();
// Send the last WorkerThread Ref to be Deref'ed on the main thread.
callOnMainThread([protectedThis = WTFMove(protectedThis)] { });
// The thread object may be already destroyed from notification now, don't try to access "this".
protector->detach();
}
void WorkerThread::startRunningDebuggerTasks()
{
ASSERT(!m_pausedForDebugger);
m_pausedForDebugger = true;
MessageQueueWaitResult result;
do {
result = m_runLoop.runInDebuggerMode(*m_workerGlobalScope);
} while (result != MessageQueueTerminated && m_pausedForDebugger);
}
void WorkerThread::stopRunningDebuggerTasks()
{
m_pausedForDebugger = false;
}
void WorkerThread::runEventLoop()
{
// Does not return until terminated.
m_runLoop.run(m_workerGlobalScope.get());
}
void WorkerThread::suspend()
{
m_isSuspended = true;
runLoop().postTask([&](ScriptExecutionContext&) {
if (m_workerGlobalScope)
m_workerGlobalScope->suspend();
m_suspensionSemaphore.wait();
if (m_workerGlobalScope)
m_workerGlobalScope->resume();
});
}
void WorkerThread::resume()
{
ASSERT(m_isSuspended);
m_isSuspended = false;
m_suspensionSemaphore.signal();
}
void WorkerThread::stop(WTF::Function<void()>&& stoppedCallback)
{
// Mutex protection is necessary to ensure that m_workerGlobalScope isn't changed by
// WorkerThread::workerThread() while we're accessing it. Note also that stop() can
// be called before m_workerGlobalScope is fully created.
auto locker = Locker<Lock>::tryLock(m_threadCreationAndWorkerGlobalScopeMutex);
if (!locker) {
// The thread is still starting, spin the runloop and try again to avoid deadlocks if the worker thread
// needs to interact with the main thread during startup.
callOnMainThread([this, stoppedCallback = WTFMove(stoppedCallback)]() mutable {
stop(WTFMove(stoppedCallback));
});
return;
}
// If the thread is suspended, resume it now so that we can dispatch the cleanup tasks below.
if (m_isSuspended)
resume();
ASSERT(!m_stoppedCallback);
m_stoppedCallback = WTFMove(stoppedCallback);
// 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.prepareForTermination();
// 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()
{
LockHolder lock(workerThreadsMutex());
for (auto* workerThread : workerThreads(lock)) {
workerThread->runLoop().postTask([] (ScriptExecutionContext&) {
WTF::releaseFastMallocFreeMemory();
});
}
}
IDBClient::IDBConnectionProxy* WorkerThread::idbConnectionProxy()
{
#if ENABLE(INDEXED_DATABASE)
return m_idbConnectionProxy.get();
#else
return nullptr;
#endif
}
SocketProvider* WorkerThread::socketProvider()
{
return m_socketProvider.get();
}
} // namespace WebCore