hw2_pt - HW2 implemented using protothread

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HW2 implemented using protothread

pt.h@0:e2cc8ae74a24, 2010-12-01 (annotated)

Committer:: the729
Date:: Wed Dec 01 02:53:56 2010 +0000
Revision:: 0:e2cc8ae74a24

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the729	0:e2cc8ae74a24	1	/*
the729	0:e2cc8ae74a24	2	* Copyright (c) 2004-2005, Swedish Institute of Computer Science.
the729	0:e2cc8ae74a24	3	* All rights reserved.
the729	0:e2cc8ae74a24	4	*
the729	0:e2cc8ae74a24	5	* Redistribution and use in source and binary forms, with or without
the729	0:e2cc8ae74a24	6	* modification, are permitted provided that the following conditions
the729	0:e2cc8ae74a24	7	* are met:
the729	0:e2cc8ae74a24	8	* 1. Redistributions of source code must retain the above copyright
the729	0:e2cc8ae74a24	9	* notice, this list of conditions and the following disclaimer.
the729	0:e2cc8ae74a24	10	* 2. Redistributions in binary form must reproduce the above copyright
the729	0:e2cc8ae74a24	11	* notice, this list of conditions and the following disclaimer in the
the729	0:e2cc8ae74a24	12	* documentation and/or other materials provided with the distribution.
the729	0:e2cc8ae74a24	13	* 3. Neither the name of the Institute nor the names of its contributors
the729	0:e2cc8ae74a24	14	* may be used to endorse or promote products derived from this software
the729	0:e2cc8ae74a24	15	* without specific prior written permission.
the729	0:e2cc8ae74a24	16	*
the729	0:e2cc8ae74a24	17	* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
the729	0:e2cc8ae74a24	18	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
the729	0:e2cc8ae74a24	19	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
the729	0:e2cc8ae74a24	20	* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
the729	0:e2cc8ae74a24	21	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
the729	0:e2cc8ae74a24	22	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
the729	0:e2cc8ae74a24	23	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
the729	0:e2cc8ae74a24	24	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
the729	0:e2cc8ae74a24	25	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
the729	0:e2cc8ae74a24	26	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
the729	0:e2cc8ae74a24	27	* SUCH DAMAGE.
the729	0:e2cc8ae74a24	28	*
the729	0:e2cc8ae74a24	29	* This file is part of the Contiki operating system.
the729	0:e2cc8ae74a24	30	*
the729	0:e2cc8ae74a24	31	* Author: Adam Dunkels <adam@sics.se>
the729	0:e2cc8ae74a24	32	*
the729	0:e2cc8ae74a24	33	* $Id: pt.h,v 1.7 2006/10/02 07:52:56 adam Exp $
the729	0:e2cc8ae74a24	34	*/
the729	0:e2cc8ae74a24	35
the729	0:e2cc8ae74a24	36	/**
the729	0:e2cc8ae74a24	37	* \addtogroup pt
the729	0:e2cc8ae74a24	38	* @{
the729	0:e2cc8ae74a24	39	*/
the729	0:e2cc8ae74a24	40
the729	0:e2cc8ae74a24	41	/**
the729	0:e2cc8ae74a24	42	* \file
the729	0:e2cc8ae74a24	43	* Protothreads implementation.
the729	0:e2cc8ae74a24	44	* \author
the729	0:e2cc8ae74a24	45	* Adam Dunkels <adam@sics.se>
the729	0:e2cc8ae74a24	46	*
the729	0:e2cc8ae74a24	47	*/
the729	0:e2cc8ae74a24	48
the729	0:e2cc8ae74a24	49	#ifndef __PT_H__
the729	0:e2cc8ae74a24	50	#define __PT_H__
the729	0:e2cc8ae74a24	51
the729	0:e2cc8ae74a24	52	#include "lc.h"
the729	0:e2cc8ae74a24	53
the729	0:e2cc8ae74a24	54	struct pt {
the729	0:e2cc8ae74a24	55	lc_t lc;
the729	0:e2cc8ae74a24	56	};
the729	0:e2cc8ae74a24	57
the729	0:e2cc8ae74a24	58	#define PT_WAITING 0
the729	0:e2cc8ae74a24	59	#define PT_YIELDED 1
the729	0:e2cc8ae74a24	60	#define PT_EXITED 2
the729	0:e2cc8ae74a24	61	#define PT_ENDED 3
the729	0:e2cc8ae74a24	62
the729	0:e2cc8ae74a24	63	/**
the729	0:e2cc8ae74a24	64	* \name Initialization
the729	0:e2cc8ae74a24	65	* @{
the729	0:e2cc8ae74a24	66	*/
the729	0:e2cc8ae74a24	67
the729	0:e2cc8ae74a24	68	/**
the729	0:e2cc8ae74a24	69	* Initialize a protothread.
the729	0:e2cc8ae74a24	70	*
the729	0:e2cc8ae74a24	71	* Initializes a protothread. Initialization must be done prior to
the729	0:e2cc8ae74a24	72	* starting to execute the protothread.
the729	0:e2cc8ae74a24	73	*
the729	0:e2cc8ae74a24	74	* \param pt A pointer to the protothread control structure.
the729	0:e2cc8ae74a24	75	*
the729	0:e2cc8ae74a24	76	* \sa PT_SPAWN()
the729	0:e2cc8ae74a24	77	*
the729	0:e2cc8ae74a24	78	* \hideinitializer
the729	0:e2cc8ae74a24	79	*/
the729	0:e2cc8ae74a24	80	#define PT_INIT(pt) LC_INIT((pt)->lc)
the729	0:e2cc8ae74a24	81
the729	0:e2cc8ae74a24	82	/** @} */
the729	0:e2cc8ae74a24	83
the729	0:e2cc8ae74a24	84	/**
the729	0:e2cc8ae74a24	85	* \name Declaration and definition
the729	0:e2cc8ae74a24	86	* @{
the729	0:e2cc8ae74a24	87	*/
the729	0:e2cc8ae74a24	88
the729	0:e2cc8ae74a24	89	/**
the729	0:e2cc8ae74a24	90	* Declaration of a protothread.
the729	0:e2cc8ae74a24	91	*
the729	0:e2cc8ae74a24	92	* This macro is used to declare a protothread. All protothreads must
the729	0:e2cc8ae74a24	93	* be declared with this macro.
the729	0:e2cc8ae74a24	94	*
the729	0:e2cc8ae74a24	95	* \param name_args The name and arguments of the C function
the729	0:e2cc8ae74a24	96	* implementing the protothread.
the729	0:e2cc8ae74a24	97	*
the729	0:e2cc8ae74a24	98	* \hideinitializer
the729	0:e2cc8ae74a24	99	*/
the729	0:e2cc8ae74a24	100	#define PT_THREAD(name_args) char name_args
the729	0:e2cc8ae74a24	101
the729	0:e2cc8ae74a24	102	/**
the729	0:e2cc8ae74a24	103	* Declare the start of a protothread inside the C function
the729	0:e2cc8ae74a24	104	* implementing the protothread.
the729	0:e2cc8ae74a24	105	*
the729	0:e2cc8ae74a24	106	* This macro is used to declare the starting point of a
the729	0:e2cc8ae74a24	107	* protothread. It should be placed at the start of the function in
the729	0:e2cc8ae74a24	108	* which the protothread runs. All C statements above the PT_BEGIN()
the729	0:e2cc8ae74a24	109	* invokation will be executed each time the protothread is scheduled.
the729	0:e2cc8ae74a24	110	*
the729	0:e2cc8ae74a24	111	* \param pt A pointer to the protothread control structure.
the729	0:e2cc8ae74a24	112	*
the729	0:e2cc8ae74a24	113	* \hideinitializer
the729	0:e2cc8ae74a24	114	*/
the729	0:e2cc8ae74a24	115	#define PT_BEGIN(pt) { char PT_YIELD_FLAG = 1; LC_RESUME((pt)->lc)
the729	0:e2cc8ae74a24	116
the729	0:e2cc8ae74a24	117	/**
the729	0:e2cc8ae74a24	118	* Declare the end of a protothread.
the729	0:e2cc8ae74a24	119	*
the729	0:e2cc8ae74a24	120	* This macro is used for declaring that a protothread ends. It must
the729	0:e2cc8ae74a24	121	* always be used together with a matching PT_BEGIN() macro.
the729	0:e2cc8ae74a24	122	*
the729	0:e2cc8ae74a24	123	* \param pt A pointer to the protothread control structure.
the729	0:e2cc8ae74a24	124	*
the729	0:e2cc8ae74a24	125	* \hideinitializer
the729	0:e2cc8ae74a24	126	*/
the729	0:e2cc8ae74a24	127	#define PT_END(pt) LC_END((pt)->lc); PT_YIELD_FLAG = 0; \
the729	0:e2cc8ae74a24	128	PT_INIT(pt); return PT_ENDED; }
the729	0:e2cc8ae74a24	129
the729	0:e2cc8ae74a24	130	/** @} */
the729	0:e2cc8ae74a24	131
the729	0:e2cc8ae74a24	132	/**
the729	0:e2cc8ae74a24	133	* \name Blocked wait
the729	0:e2cc8ae74a24	134	* @{
the729	0:e2cc8ae74a24	135	*/
the729	0:e2cc8ae74a24	136
the729	0:e2cc8ae74a24	137	/**
the729	0:e2cc8ae74a24	138	* Block and wait until condition is true.
the729	0:e2cc8ae74a24	139	*
the729	0:e2cc8ae74a24	140	* This macro blocks the protothread until the specified condition is
the729	0:e2cc8ae74a24	141	* true.
the729	0:e2cc8ae74a24	142	*
the729	0:e2cc8ae74a24	143	* \param pt A pointer to the protothread control structure.
the729	0:e2cc8ae74a24	144	* \param condition The condition.
the729	0:e2cc8ae74a24	145	*
the729	0:e2cc8ae74a24	146	* \hideinitializer
the729	0:e2cc8ae74a24	147	*/
the729	0:e2cc8ae74a24	148	#define PT_WAIT_UNTIL(pt, condition) \
the729	0:e2cc8ae74a24	149	do { \
the729	0:e2cc8ae74a24	150	LC_SET((pt)->lc); \
the729	0:e2cc8ae74a24	151	if(!(condition)) { \
the729	0:e2cc8ae74a24	152	return PT_WAITING; \
the729	0:e2cc8ae74a24	153	} \
the729	0:e2cc8ae74a24	154	} while(0)
the729	0:e2cc8ae74a24	155
the729	0:e2cc8ae74a24	156	/**
the729	0:e2cc8ae74a24	157	* Block and wait while condition is true.
the729	0:e2cc8ae74a24	158	*
the729	0:e2cc8ae74a24	159	* This function blocks and waits while condition is true. See
the729	0:e2cc8ae74a24	160	* PT_WAIT_UNTIL().
the729	0:e2cc8ae74a24	161	*
the729	0:e2cc8ae74a24	162	* \param pt A pointer to the protothread control structure.
the729	0:e2cc8ae74a24	163	* \param cond The condition.
the729	0:e2cc8ae74a24	164	*
the729	0:e2cc8ae74a24	165	* \hideinitializer
the729	0:e2cc8ae74a24	166	*/
the729	0:e2cc8ae74a24	167	#define PT_WAIT_WHILE(pt, cond) PT_WAIT_UNTIL((pt), !(cond))
the729	0:e2cc8ae74a24	168
the729	0:e2cc8ae74a24	169	/** @} */
the729	0:e2cc8ae74a24	170
the729	0:e2cc8ae74a24	171	/**
the729	0:e2cc8ae74a24	172	* \name Hierarchical protothreads
the729	0:e2cc8ae74a24	173	* @{
the729	0:e2cc8ae74a24	174	*/
the729	0:e2cc8ae74a24	175
the729	0:e2cc8ae74a24	176	/**
the729	0:e2cc8ae74a24	177	* Block and wait until a child protothread completes.
the729	0:e2cc8ae74a24	178	*
the729	0:e2cc8ae74a24	179	* This macro schedules a child protothread. The current protothread
the729	0:e2cc8ae74a24	180	* will block until the child protothread completes.
the729	0:e2cc8ae74a24	181	*
the729	0:e2cc8ae74a24	182	* \note The child protothread must be manually initialized with the
the729	0:e2cc8ae74a24	183	* PT_INIT() function before this function is used.
the729	0:e2cc8ae74a24	184	*
the729	0:e2cc8ae74a24	185	* \param pt A pointer to the protothread control structure.
the729	0:e2cc8ae74a24	186	* \param thread The child protothread with arguments
the729	0:e2cc8ae74a24	187	*
the729	0:e2cc8ae74a24	188	* \sa PT_SPAWN()
the729	0:e2cc8ae74a24	189	*
the729	0:e2cc8ae74a24	190	* \hideinitializer
the729	0:e2cc8ae74a24	191	*/
the729	0:e2cc8ae74a24	192	#define PT_WAIT_THREAD(pt, thread) PT_WAIT_WHILE((pt), PT_SCHEDULE(thread))
the729	0:e2cc8ae74a24	193
the729	0:e2cc8ae74a24	194	/**
the729	0:e2cc8ae74a24	195	* Spawn a child protothread and wait until it exits.
the729	0:e2cc8ae74a24	196	*
the729	0:e2cc8ae74a24	197	* This macro spawns a child protothread and waits until it exits. The
the729	0:e2cc8ae74a24	198	* macro can only be used within a protothread.
the729	0:e2cc8ae74a24	199	*
the729	0:e2cc8ae74a24	200	* \param pt A pointer to the protothread control structure.
the729	0:e2cc8ae74a24	201	* \param child A pointer to the child protothread's control structure.
the729	0:e2cc8ae74a24	202	* \param thread The child protothread with arguments
the729	0:e2cc8ae74a24	203	*
the729	0:e2cc8ae74a24	204	* \hideinitializer
the729	0:e2cc8ae74a24	205	*/
the729	0:e2cc8ae74a24	206	#define PT_SPAWN(pt, child, thread) \
the729	0:e2cc8ae74a24	207	do { \
the729	0:e2cc8ae74a24	208	PT_INIT((child)); \
the729	0:e2cc8ae74a24	209	PT_WAIT_THREAD((pt), (thread)); \
the729	0:e2cc8ae74a24	210	} while(0)
the729	0:e2cc8ae74a24	211
the729	0:e2cc8ae74a24	212	/** @} */
the729	0:e2cc8ae74a24	213
the729	0:e2cc8ae74a24	214	/**
the729	0:e2cc8ae74a24	215	* \name Exiting and restarting
the729	0:e2cc8ae74a24	216	* @{
the729	0:e2cc8ae74a24	217	*/
the729	0:e2cc8ae74a24	218
the729	0:e2cc8ae74a24	219	/**
the729	0:e2cc8ae74a24	220	* Restart the protothread.
the729	0:e2cc8ae74a24	221	*
the729	0:e2cc8ae74a24	222	* This macro will block and cause the running protothread to restart
the729	0:e2cc8ae74a24	223	* its execution at the place of the PT_BEGIN() call.
the729	0:e2cc8ae74a24	224	*
the729	0:e2cc8ae74a24	225	* \param pt A pointer to the protothread control structure.
the729	0:e2cc8ae74a24	226	*
the729	0:e2cc8ae74a24	227	* \hideinitializer
the729	0:e2cc8ae74a24	228	*/
the729	0:e2cc8ae74a24	229	#define PT_RESTART(pt) \
the729	0:e2cc8ae74a24	230	do { \
the729	0:e2cc8ae74a24	231	PT_INIT(pt); \
the729	0:e2cc8ae74a24	232	return PT_WAITING; \
the729	0:e2cc8ae74a24	233	} while(0)
the729	0:e2cc8ae74a24	234
the729	0:e2cc8ae74a24	235	/**
the729	0:e2cc8ae74a24	236	* Exit the protothread.
the729	0:e2cc8ae74a24	237	*
the729	0:e2cc8ae74a24	238	* This macro causes the protothread to exit. If the protothread was
the729	0:e2cc8ae74a24	239	* spawned by another protothread, the parent protothread will become
the729	0:e2cc8ae74a24	240	* unblocked and can continue to run.
the729	0:e2cc8ae74a24	241	*
the729	0:e2cc8ae74a24	242	* \param pt A pointer to the protothread control structure.
the729	0:e2cc8ae74a24	243	*
the729	0:e2cc8ae74a24	244	* \hideinitializer
the729	0:e2cc8ae74a24	245	*/
the729	0:e2cc8ae74a24	246	#define PT_EXIT(pt) \
the729	0:e2cc8ae74a24	247	do { \
the729	0:e2cc8ae74a24	248	PT_INIT(pt); \
the729	0:e2cc8ae74a24	249	return PT_EXITED; \
the729	0:e2cc8ae74a24	250	} while(0)
the729	0:e2cc8ae74a24	251
the729	0:e2cc8ae74a24	252	/** @} */
the729	0:e2cc8ae74a24	253
the729	0:e2cc8ae74a24	254	/**
the729	0:e2cc8ae74a24	255	* \name Calling a protothread
the729	0:e2cc8ae74a24	256	* @{
the729	0:e2cc8ae74a24	257	*/
the729	0:e2cc8ae74a24	258
the729	0:e2cc8ae74a24	259	/**
the729	0:e2cc8ae74a24	260	* Schedule a protothread.
the729	0:e2cc8ae74a24	261	*
the729	0:e2cc8ae74a24	262	* This function shedules a protothread. The return value of the
the729	0:e2cc8ae74a24	263	* function is non-zero if the protothread is running or zero if the
the729	0:e2cc8ae74a24	264	* protothread has exited.
the729	0:e2cc8ae74a24	265	*
the729	0:e2cc8ae74a24	266	* \param f The call to the C function implementing the protothread to
the729	0:e2cc8ae74a24	267	* be scheduled
the729	0:e2cc8ae74a24	268	*
the729	0:e2cc8ae74a24	269	* \hideinitializer
the729	0:e2cc8ae74a24	270	*/
the729	0:e2cc8ae74a24	271	#define PT_SCHEDULE(f) ((f) < PT_EXITED)
the729	0:e2cc8ae74a24	272
the729	0:e2cc8ae74a24	273	/** @} */
the729	0:e2cc8ae74a24	274
the729	0:e2cc8ae74a24	275	/**
the729	0:e2cc8ae74a24	276	* \name Yielding from a protothread
the729	0:e2cc8ae74a24	277	* @{
the729	0:e2cc8ae74a24	278	*/
the729	0:e2cc8ae74a24	279
the729	0:e2cc8ae74a24	280	/**
the729	0:e2cc8ae74a24	281	* Yield from the current protothread.
the729	0:e2cc8ae74a24	282	*
the729	0:e2cc8ae74a24	283	* This function will yield the protothread, thereby allowing other
the729	0:e2cc8ae74a24	284	* processing to take place in the system.
the729	0:e2cc8ae74a24	285	*
the729	0:e2cc8ae74a24	286	* \param pt A pointer to the protothread control structure.
the729	0:e2cc8ae74a24	287	*
the729	0:e2cc8ae74a24	288	* \hideinitializer
the729	0:e2cc8ae74a24	289	*/
the729	0:e2cc8ae74a24	290	#define PT_YIELD(pt) \
the729	0:e2cc8ae74a24	291	do { \
the729	0:e2cc8ae74a24	292	PT_YIELD_FLAG = 0; \
the729	0:e2cc8ae74a24	293	LC_SET((pt)->lc); \
the729	0:e2cc8ae74a24	294	if(PT_YIELD_FLAG == 0) { \
the729	0:e2cc8ae74a24	295	return PT_YIELDED; \
the729	0:e2cc8ae74a24	296	} \
the729	0:e2cc8ae74a24	297	} while(0)
the729	0:e2cc8ae74a24	298
the729	0:e2cc8ae74a24	299	/**
the729	0:e2cc8ae74a24	300	* \brief Yield from the protothread until a condition occurs.
the729	0:e2cc8ae74a24	301	* \param pt A pointer to the protothread control structure.
the729	0:e2cc8ae74a24	302	* \param cond The condition.
the729	0:e2cc8ae74a24	303	*
the729	0:e2cc8ae74a24	304	* This function will yield the protothread, until the
the729	0:e2cc8ae74a24	305	* specified condition evaluates to true.
the729	0:e2cc8ae74a24	306	*
the729	0:e2cc8ae74a24	307	*
the729	0:e2cc8ae74a24	308	* \hideinitializer
the729	0:e2cc8ae74a24	309	*/
the729	0:e2cc8ae74a24	310	#define PT_YIELD_UNTIL(pt, cond) \
the729	0:e2cc8ae74a24	311	do { \
the729	0:e2cc8ae74a24	312	PT_YIELD_FLAG = 0; \
the729	0:e2cc8ae74a24	313	LC_SET((pt)->lc); \
the729	0:e2cc8ae74a24	314	if((PT_YIELD_FLAG == 0) \|\| !(cond)) { \
the729	0:e2cc8ae74a24	315	return PT_YIELDED; \
the729	0:e2cc8ae74a24	316	} \
the729	0:e2cc8ae74a24	317	} while(0)
the729	0:e2cc8ae74a24	318
the729	0:e2cc8ae74a24	319	/** @} */
the729	0:e2cc8ae74a24	320
the729	0:e2cc8ae74a24	321	#endif /* __PT_H__ */
the729	0:e2cc8ae74a24	322
the729	0:e2cc8ae74a24	323	/** @} */

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	01 Dec 2010
Imports:	2
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	2

pt.h@0:e2cc8ae74a24, 2010-12-01 (annotated)

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