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/**
 * @file sem.hpp
 *
 * C++ synchronization helpers
 */

#pragma once

#include "sem.h"


/**
 * @class Smart locking object that uses a semaphore. It automatically
 * takes the lock when created and releases the lock when the object goes out of
 * scope. Use like this:
 *
 *   px4_sem_t my_lock;
 *   int ret = px4_sem_init(&my_lock, 0, 1);
 *   ...
 *
 *   {
 *       SmartLock smart_lock(my_lock);
 *       //critical section start
 *       ...
 *       //critical section end
 *   }
 */
class SmartLock
{
public:
	SmartLock(px4_sem_t &sem) : _sem(sem) { do {} while (px4_sem_wait(&_sem) != 0); }
	~SmartLock() { px4_sem_post(&_sem); }
private:
	px4_sem_t &_sem;
};