/**
* @brief Tries to lock a mutex.
* @details This function attempts to lock a mutex, if the mutex is already
* locked by another thread then the function exits without waiting.
* @post The mutex is locked and inserted in the per-thread stack of owned
* mutexes.
* @note This function does not have any overhead related to the
* priority inheritance mechanism because it does not try to
* enter a sleep state.
*
* @param[in] mp pointer to the @p mutex_t structure
* @return The operation status.
* @retval true if the mutex has been successfully acquired
* @retval false if the lock attempt failed.
*
* @api
*/
bool chMtxTryLock(mutex_t *mp) {
bool b;
chSysLock();
b = chMtxTryLockS(mp);
chSysUnlock();
return b;
}
/**
* @brief Tries to lock a mutex.
* @details This function attempts to lock a mutex, if the mutex is already
* locked by another thread then the function exits without waiting.
* @post The mutex is locked and inserted in the per-thread stack of owned
* mutexes.
* @note This function does not have any overhead related to the
* priority inheritance mechanism because it does not try to
* enter a sleep state.
*
* @param[in] mp pointer to the @p Mutex structure
* @return The operation status.
* @retval TRUE if the mutex has been successfully acquired
* @retval FALSE if the lock attempt failed.
*
* @api
*/
bool_t chMtxTryLock(Mutex *mp) {
bool_t b;
chSysLock();
b = chMtxTryLockS(mp);
chSysUnlock();
return b;
}
bool Mutex::tryLockS(void) {
return chMtxTryLockS(&mutex);
}
static void test_005_006_execute(void) {
bool b;
tprio_t prio;
/* [5.6.1] Getting current thread priority for later checks.*/
test_set_step(1);
{
prio = chThdGetPriorityX();
}
/* [5.6.2] Locking the mutex first time, it must be possible because
it is not owned.*/
test_set_step(2);
{
b = chMtxTryLock(&m1);
test_assert(b, "already locked");
}
/* [5.6.3] Locking the mutex second time, it must be possible because
it is recursive.*/
test_set_step(3);
{
b = chMtxTryLock(&m1);
test_assert(b, "already locked");
}
/* [5.6.4] Unlocking the mutex then it must be still owned because
recursivity.*/
test_set_step(4);
{
chMtxUnlock(&m1);
test_assert(m1.owner != NULL, "not owned");
}
/* [5.6.5] Unlocking the mutex then it must not be owned anymore and
the queue must be empty.*/
test_set_step(5);
{
chMtxUnlock(&m1);
test_assert(m1.owner == NULL, "still owned");
test_assert(queue_isempty(&m1.queue), "queue not empty");
}
/* [5.6.6] Testing that priority has not changed after operations.*/
test_set_step(6);
{
test_assert(chThdGetPriorityX() == prio, "wrong priority level");
}
/* [5.6.7] Testing consecutive chMtxTryLock()/chMtxTryLockS() calls
and a final chMtxUnlockAllS().*/
test_set_step(7);
{
b = chMtxTryLock(&m1);
test_assert(b, "already locked");
chSysLock();
b = chMtxTryLockS(&m1);
chSysUnlock();
test_assert(b, "already locked");
test_assert(m1.cnt == 2, "invalid recursion counter");
chSysLock();
chMtxUnlockAllS();
chSysUnlock();
test_assert(m1.owner == NULL, "still owned");
test_assert(queue_isempty(&m1.queue), "queue not empty");
test_assert(m1.cnt == 0, "invalid recursion counter");
}
/* [5.6.8] Testing consecutive chMtxLock()/chMtxLockS() calls and a
final chMtxUnlockAll().*/
test_set_step(8);
{
chMtxLock(&m1);
test_assert(m1.owner != NULL, "not owned");
chSysLock();
chMtxLockS(&m1);
chSysUnlock();
test_assert(m1.owner != NULL, "not owned");
test_assert(m1.cnt == 2, "invalid recursion counter");
chMtxUnlockAll();
test_assert(m1.owner == NULL, "still owned");
test_assert(queue_isempty(&m1.queue), "queue not empty");
test_assert(m1.cnt == 0, "invalid recursion counter");
}
/* [5.6.9] Testing that priority has not changed after operations.*/
test_set_step(9);
{
test_assert(chThdGetPriorityX() == prio, "wrong priority level");
}
}
