/*

* Copyright (C) 2005-2017 Apple Inc. All rights reserved.

* (C) 2007 Graham Dennis (graham.dennis@gmail.com)

* (C) 2007 Eric Seidel <eric@webkit.org>

* (C) 2012 Patrick Ganstere <paroga@paroga.com>

*

* 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.

* 3. Neither the name of Apple Inc. ("Apple") nor the names of

* its contributors may be used to endorse or promote products derived

* from this software without specific prior written permission.

*

* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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 "JavaScriptThreading.h"

#include <JavaScriptCore/JavaScriptCore.h>

#include <stdlib.h>

#include <wtf/Assertions.h>

#include <wtf/HashSet.h>

#include <wtf/Lock.h>

#include <wtf/NeverDestroyed.h>

#include <wtf/Threading.h>

#include <wtf/ThreadingPrimitives.h>

#include <wtf/Vector.h>

static const size_t javaScriptThreadsCount = 4;

static bool javaScriptThreadsShouldTerminate;

static JSContextGroupRef javaScriptThreadsGroup;

static Lock javaScriptThreadsLock;

typedef HashSet<RefPtr<Thread>> ThreadSet;

static ThreadSet& javaScriptThreads()

{

static NeverDestroyed<ThreadSet> staticJavaScriptThreads;

ASSERT(!javaScriptThreadsLock.tryLock());

return staticJavaScriptThreads;

}

// This function exercises JSC in a loop until javaScriptThreadsShouldTerminate

// becomes true or it probabilistically decides to spawn a replacement thread and exit.

void runJavaScriptThread()

{

static const char* const script =

"var array = [];"

"for (var i = 0; i < 1024; i++) {"

" array.push(String(i));"

"}";

JSGlobalContextRef ctx;

{

Locker locker { javaScriptThreadsLock };

ctx = JSGlobalContextCreateInGroup(javaScriptThreadsGroup, 0);

}

JSStringRef scriptRef;

{

Locker locker { javaScriptThreadsLock };

scriptRef = JSStringCreateWithUTF8CString(script);

}

while (true) {

{

Locker locker { javaScriptThreadsLock };

JSValueRef exception = 0;

JSEvaluateScript(ctx, scriptRef, 0, 0, 1, &exception);

ASSERT(!exception);

}

{

Locker locker { javaScriptThreadsLock };

const size_t valuesCount = 1024;

JSValueRef values[valuesCount];

for (size_t i = 0; i < valuesCount; ++i)

values[i] = JSObjectMake(ctx, 0, 0);

}

{

Locker locker { javaScriptThreadsLock };

if (javaScriptThreadsShouldTerminate)

break;

}

// Respawn probabilistically.

if (rand() % 5)

continue;

Locker locker { javaScriptThreadsLock };

Thread& thread = Thread::current();

thread.detach();

javaScriptThreads().remove(&thread);

javaScriptThreads().add(Thread::create("JavaScript Thread", &runJavaScriptThread));

break;

}

Locker locker { javaScriptThreadsLock };

JSStringRelease(scriptRef);

JSGarbageCollect(ctx);

JSGlobalContextRelease(ctx);

}

void startJavaScriptThreads()

{

javaScriptThreadsGroup = JSContextGroupCreate();

Locker locker { javaScriptThreadsLock };

for (size_t i = 0; i < javaScriptThreadsCount; ++i)

javaScriptThreads().add(Thread::create("JavaScript Thread", &runJavaScriptThread));

}

void stopJavaScriptThreads()

{

{

Locker locker { javaScriptThreadsLock };

javaScriptThreadsShouldTerminate = true;

}

Vector<RefPtr<Thread>, javaScriptThreadsCount> threads;

{

Locker locker { javaScriptThreadsLock };

threads = copyToVector(javaScriptThreads());

ASSERT(threads.size() == javaScriptThreadsCount);

}

for (size_t i = 0; i < javaScriptThreadsCount; ++i)

threads[i]->waitForCompletion();

{

Locker locker { javaScriptThreadsLock };

javaScriptThreads().clear();

}

JSContextGroupRelease(javaScriptThreadsGroup);

}