mirror of https://github.com/ArduPilot/ardupilot
51 lines
1.5 KiB
C++
51 lines
1.5 KiB
C++
/*
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This program 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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This program 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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#pragma once
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/*
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a method to make semaphores less error prone. The WITH_SEMAPHORE()
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macro will block forever for a semaphore, and will automatically
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release the semaphore when it goes out of scope
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Note that we have two types of semaphores. A normal semaphore can
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only be taken once. A recursive semaphore allows for the thread
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holding the semaphore to take it again. It must be released the same
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number of times it is taken.
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The WITH_SEMAPHORE() macro can be used with either type of semaphore
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*/
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namespace AP_HAL {
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class Semaphore;
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}
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class WithSemaphore {
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public:
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WithSemaphore(AP_HAL::Semaphore *mtx) : WithSemaphore(*mtx) { }
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WithSemaphore(AP_HAL::Semaphore &mtx) : _mtx(mtx) {
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_mtx.take_blocking();
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}
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~WithSemaphore() {
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_mtx.give();
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}
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private:
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AP_HAL::Semaphore &_mtx;
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};
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#define WITH_SEMAPHORE(sem) WithSemaphore _getsem ## __UNIQ__(sem)
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