[apple/security.git] / OSX / libsecurity_utilities / lib / dispatch.h

/*
 * Copyright (c) 2014 Apple Inc. All Rights Reserved.
 * 
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */

//
// dispatch - libdispatch wrapper
//
#ifndef _H_DISPATCH
#define _H_DISPATCH

#include <dispatch/dispatch.h>
#include <security_utilities/utilities.h>
#include <security_utilities/threading.h>

#include <exception>

namespace Security {
namespace Dispatch {


// Wraps dispatch objects which can be used to queue blocks, i.e. dispatch groups and queues.
// If a block throws an exception, no further blocks are enqueued and the exception is rethrown
// after waiting for completion of all blocks.
class ExceptionAwareEnqueuing {
	NOCOPY(ExceptionAwareEnqueuing)
public:
	ExceptionAwareEnqueuing();

	void enqueueWithDispatcher(void (^dispatcher)(dispatch_block_t), dispatch_block_t block);
	void throwPendingException();
private:
	Mutex mLock;
	bool mExceptionPending;
	std::exception_ptr mException;
};


class Queue {
	NOCOPY(Queue)
public:
	Queue(const char *label, bool concurrent, dispatch_qos_class_t qos_class = QOS_CLASS_UNSPECIFIED);
	virtual ~Queue();

	operator dispatch_queue_t () const { return mQueue; }

	void enqueue(dispatch_block_t block);
	void wait();

private:
	ExceptionAwareEnqueuing enqueuing;
	dispatch_queue_t mQueue;
};


class Group {
	NOCOPY(Group)
public:
	Group();
	virtual ~Group();

	operator dispatch_group_t () const { return mGroup; }

	void enqueue(dispatch_queue_t queue, dispatch_block_t block);
	void wait();

private:
	ExceptionAwareEnqueuing enqueuing;
	dispatch_group_t mGroup;
};


class Semaphore {
	NOCOPY(Semaphore)
public:
	Semaphore(long count);
	Semaphore(Semaphore& semaphore);
	virtual ~Semaphore();

	operator dispatch_semaphore_t () const { return mSemaphore; };

	bool signal();
	bool wait(dispatch_time_t timeout = DISPATCH_TIME_FOREVER);

private:
	dispatch_semaphore_t mSemaphore;
};


class SemaphoreWait {
	NOCOPY(SemaphoreWait)
public:
	SemaphoreWait(SemaphoreWait& originalWait);
	SemaphoreWait(Semaphore& semaphore, dispatch_time_t timeout = DISPATCH_TIME_FOREVER);
	virtual ~SemaphoreWait();

	bool acquired() const { return mAcquired; };

private:
	Semaphore &mSemaphore;
	bool mAcquired;
};


} // end namespace Dispatch
} // end namespace Security

#endif // !_H_DISPATCH
Commit	Line	Data
d87e1158 A	1	/*
	2	* Copyright (c) 2014 Apple Inc. All Rights Reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. Please obtain a copy of the License at
	10	* http://www.opensource.apple.com/apsl/ and read it before using this
	11	* file.
	12	*
	13	* The Original Code and all software distributed under the License are
	14	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	15	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	16	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	17	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	18	* Please see the License for the specific language governing rights and
	19	* limitations under the License.
	20	*
	21	* @APPLE_LICENSE_HEADER_END@
	22	*/
	23
	24	//
	25	// dispatch - libdispatch wrapper
	26	//
	27	#ifndef _H_DISPATCH
	28	#define _H_DISPATCH
	29
	30	#include <dispatch/dispatch.h>
	31	#include <security_utilities/utilities.h>
	32	#include <security_utilities/threading.h>
	33
	34	#include <exception>
	35
	36	namespace Security {
	37	namespace Dispatch {
	38
	39
	40	// Wraps dispatch objects which can be used to queue blocks, i.e. dispatch groups and queues.
	41	// If a block throws an exception, no further blocks are enqueued and the exception is rethrown
	42	// after waiting for completion of all blocks.
	43	class ExceptionAwareEnqueuing {
	44	NOCOPY(ExceptionAwareEnqueuing)
	45	public:
	46	ExceptionAwareEnqueuing();
	47
	48	void enqueueWithDispatcher(void (^dispatcher)(dispatch_block_t), dispatch_block_t block);
	49	void throwPendingException();
	50	private:
	51	Mutex mLock;
	52	bool mExceptionPending;
	53	std::exception_ptr mException;
	54	};
	55
	56
	57	class Queue {
	58	NOCOPY(Queue)
	59	public:
866f8763	60	Queue(const char *label, bool concurrent, dispatch_qos_class_t qos_class = QOS_CLASS_UNSPECIFIED);
d87e1158 A	61	virtual ~Queue();
	62
	63	operator dispatch_queue_t () const { return mQueue; }
	64
	65	void enqueue(dispatch_block_t block);
	66	void wait();
	67
	68	private:
	69	ExceptionAwareEnqueuing enqueuing;
	70	dispatch_queue_t mQueue;
	71	};
	72
	73
	74	class Group {
	75	NOCOPY(Group)
	76	public:
	77	Group();
	78	virtual ~Group();
	79
	80	operator dispatch_group_t () const { return mGroup; }
	81
	82	void enqueue(dispatch_queue_t queue, dispatch_block_t block);
	83	void wait();
	84
	85	private:
	86	ExceptionAwareEnqueuing enqueuing;
	87	dispatch_group_t mGroup;
	88	};
	89
	90
	91	class Semaphore {
	92	NOCOPY(Semaphore)
	93	public:
	94	Semaphore(long count);
	95	Semaphore(Semaphore& semaphore);
	96	virtual ~Semaphore();
	97
	98	operator dispatch_semaphore_t () const { return mSemaphore; };
	99
	100	bool signal();
	101	bool wait(dispatch_time_t timeout = DISPATCH_TIME_FOREVER);
	102
	103	private:
	104	dispatch_semaphore_t mSemaphore;
	105	};
	106
	107
	108	class SemaphoreWait {
	109	NOCOPY(SemaphoreWait)
	110	public:
	111	SemaphoreWait(SemaphoreWait& originalWait);
	112	SemaphoreWait(Semaphore& semaphore, dispatch_time_t timeout = DISPATCH_TIME_FOREVER);
	113	virtual ~SemaphoreWait();
	114
	115	bool acquired() const { return mAcquired; };
	116
	117	private:
	118	Semaphore &mSemaphore;
	119	bool mAcquired;
	120	};
	121
	122
	123	} // end namespace Dispatch
	124	} // end namespace Security
125
126	#endif // !_H_DISPATCH