58 lines
2.2 KiB
Plaintext
58 lines
2.2 KiB
Plaintext
/*
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ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio.
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This file is part of ChibiOS/RT.
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ChibiOS/RT is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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ChibiOS/RT is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/**
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* @page article_atomic Invoking multiple primitives as a single atomic operation
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* It is often necessary to invoke multiple operations involving a
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* reschedulation as a single atomic operation.<br>
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* ChibiOS/RT already implements APIs that perform complex operations, as
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* example the API @p chSemSignalWait() performs two operations atomically.<br>
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* If more complex operations are required in your application then it is
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* possible to build macro-operations, see the following example:
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* @code
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chSysLock();
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chSemSignalI(&sem1);
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chSemSignalI(&sem2);
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chMtxUnlockS();
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chSchRescheduleS();
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chSysUnlock();
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* @endcode
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* The above example performs a signal operation on two semaphores, unlocks the
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* last aquired mutex and finally performs a reschedulation. All the operations
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* are performed atomically.<br>
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* An hypotetical @p chSemSignalSignalWait() operation could be implemented as
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* follow:
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* @code
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chSysLock();
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chSemSignalI(&sem1);
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chSemSignalI(&sem2);
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chSemWaitS(&Sem3); /* May reschedule or not. */
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chSchRescheduleS(); /* This one reschedules if necessary. */
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chSysUnlock();
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* @endcode
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* In general multiple @ref I-Class and (non rescheduling) @ref S-Class APIs
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* can be included and the block is terminated by a rescheduling @ref S-Class
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* API. An extra @p chSchRescheduleS() can be present at the very end of the
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* block, it only reschedules if a reschedulation is still required.
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*/
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