/*
 * Copyright (C) 2008 Apple Inc. All Rights Reserved.
 * Copyright (C) 2012 Google 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. 
 *
 */

#pragma once

#if ENABLE(WORKERS)

#include <heap/Strong.h>
#include <wtf/Forward.h>
#include <wtf/NakedPtr.h>
#include <wtf/Threading.h>

namespace JSC {
	class Exception;
    class JSGlobalData;
}

namespace WebCore {

class JSWorkerGlobalScope;
class ScriptSourceCode;
class ScriptValue;
class WorkerGlobalScope;

class WorkerScriptController {
	WTF_MAKE_NONCOPYABLE(WorkerScriptController); WTF_MAKE_FAST_ALLOCATED;
public:
	WorkerScriptController(WorkerGlobalScope*);
	~WorkerScriptController();

	JSWorkerGlobalScope* workerGlobalScopeWrapper()
	{
		initScriptIfNeeded();
		return m_workerGlobalScopeWrapper.get();
	}

	JSWorkerGlobalScope* globalScopeWrapper()
	{
	    return workerGlobalScopeWrapper();
	}

	void evaluate(const ScriptSourceCode&, String* returnedExceptionMessage = nullptr);
	void evaluate(const ScriptSourceCode&, NakedPtr<JSC::Exception>& returnedException, String* returnedExceptionMessage = nullptr);

	void setException(JSC::Exception*);

	// Async request to terminate a JS run execution. Eventually causes termination
	// exception raised during JS execution, if the worker thread happens to run JS.
	// After JS execution was terminated in this way, the Worker thread has to use
	// forbidExecution()/isExecutionForbidden() to guard against reentry into JS.
	// Can be called from any thread.
	void scheduleExecutionTermination();
	bool isTerminatingExecution() const;
	bool isExecutionTerminating() const { return isTerminatingExecution(); }

	// Called on Worker thread when JS exits with termination exception caused by forbidExecution() request,
	// or by Worker thread termination code to prevent future entry into JS.
	void forbidExecution();
	bool isExecutionForbidden() const;

	void disableEval(const String& errorMessage);

	JSC::JSGlobalData* globalData() const { return m_vm.get(); }
	JSC::JSGlobalData* vm() const { return m_vm.get(); }

private:
	ALWAYS_INLINE void initScriptIfNeeded()
	{
		if (UNLIKELY(!m_workerGlobalScopeWrapper))
			initScript();
	}
	void initScript();

	RefPtr<JSC::JSGlobalData> m_vm;
	WorkerGlobalScope* m_workerGlobalScope;
	JSC::Strong<JSWorkerGlobalScope> m_workerGlobalScopeWrapper;
	bool m_executionForbidden;
	bool m_isTerminatingExecution;
	mutable Mutex m_scheduledTerminationMutex;
};

} // namespace WebCore

#endif // ENABLE(WORKERS)
