/**
* \b atomSemGet
*
* Perform a get operation on a semaphore.
*
* This decrements the current count value for the semaphore and returns.
* If the count value is already zero then the call will block until the
* count is incremented by another thread, or until the specified \c timeout
* is reached. Blocking threads will also be woken if the semaphore is
* deleted by another thread while blocking.
*
* Depending on the \c timeout value specified the call will do one of
* the following if the count value is zero:
*
* \c timeout == 0 : Call will block until the count is non-zero \n
* \c timeout > 0 : Call will block until non-zero up to the specified timeout \n
* \c timeout == -1 : Return immediately if the count is zero \n
*
* If the call needs to block and \c timeout is zero, it will block
* indefinitely until atomSemPut() or atomSemDelete() is called on the
* semaphore.
*
* If the call needs to block and \c timeout is non-zero, the call will only
* block for the specified number of system ticks after which time, if the
* thread was not already woken, the call will return with \c ATOM_TIMEOUT.
*
* If the call would normally block and \c timeout is -1, the call will
* return immediately with \c ATOM_WOULDBLOCK.
*
* This function can only be called from interrupt context if the \c timeout
* parameter is -1 (in which case it does not block).
*
* @param[in] sem Pointer to semaphore object
* @param[in] timeout Max system ticks to block (0 = forever)
*
* @retval ATOM_OK Success
* @retval ATOM_TIMEOUT Semaphore timed out before being woken
* @retval ATOM_WOULDBLOCK Called with timeout == -1 but count is zero
* @retval ATOM_ERR_DELETED Semaphore was deleted while suspended
* @retval ATOM_ERR_CONTEXT Not called in thread context and attempted to block
* @retval ATOM_ERR_PARAM Bad parameter
* @retval ATOM_ERR_QUEUE Problem putting the thread on the suspend queue
* @retval ATOM_ERR_TIMER Problem registering the timeout
*/
uint8_t atomSemGet (ATOM_SEM *sem, int32_t timeout)
{
CRITICAL_STORE;
uint8_t status;
SEM_TIMER timer_data;
ATOM_TIMER timer_cb;
ATOM_TCB *curr_tcb_ptr;
/* Check parameters */
if (sem == NULL)
{
/* Bad semaphore pointer */
status = ATOM_ERR_PARAM;
}
else
{
/* Protect access to the semaphore object and OS queues */
CRITICAL_START ();
/* If count is zero, block the calling thread */
if (sem->count == 0)
{
/* If called with timeout >= 0, we should block */
if (timeout >= 0)
{
/* Count is zero, block the calling thread */
/* Get the current TCB */
curr_tcb_ptr = atomCurrentContext();
/* Check we are actually in thread context */
if (curr_tcb_ptr)
{
/* Add current thread to the suspend list on this semaphore */
if (tcbEnqueuePriority (&sem->suspQ, curr_tcb_ptr) != ATOM_OK)
{
/* Exit critical region */
CRITICAL_END ();
/* There was an error putting this thread on the suspend list */
status = ATOM_ERR_QUEUE;
}
else
{
/* Set suspended status for the current thread */
curr_tcb_ptr->suspended = TRUE;
/* Track errors */
status = ATOM_OK;
/* Register a timer callback if requested */
if (timeout)
{
/* Fill out the data needed by the callback to wake us up */
timer_data.tcb_ptr = curr_tcb_ptr;
timer_data.sem_ptr = sem;
/* Fill out the timer callback request structure */
timer_cb.cb_func = atomSemTimerCallback;
timer_cb.cb_data = (POINTER)&timer_data;
timer_cb.cb_ticks = timeout;
/**
* Store the timer details in the TCB so that we can
* cancel the timer callback if the semaphore is put
* before the timeout occurs.
*/
curr_tcb_ptr->suspend_timo_cb = &timer_cb;
/* Register a callback on timeout */
if (atomTimerRegister (&timer_cb) != ATOM_OK)
{
/* Timer registration failed */
status = ATOM_ERR_TIMER;
/* Clean up and return to the caller */
(void)tcbDequeueEntry (&sem->suspQ, curr_tcb_ptr);
curr_tcb_ptr->suspended = FALSE;
curr_tcb_ptr->suspend_timo_cb = NULL;
}
}
/* Set no timeout requested */
else
{
/* No need to cancel timeouts on this one */
curr_tcb_ptr->suspend_timo_cb = NULL;
}
/* Exit critical region */
CRITICAL_END ();
/* Check no errors have occurred */
if (status == ATOM_OK)
{
/**
* Current thread now blocking, schedule in a new
* one. We already know we are in thread context
* so can call the scheduler from here.
*/
atomSched (FALSE);
/**
* Normal atomSemPut() wakeups will set ATOM_OK status,
* while timeouts will set ATOM_TIMEOUT and semaphore
* deletions will set ATOM_ERR_DELETED.
*/
status = curr_tcb_ptr->suspend_wake_status;
/**
* If we have been woken up with ATOM_OK then
* another thread incremented the semaphore and
* handed control to this thread. In theory the
* the posting thread increments the counter and
* as soon as this thread wakes up we decrement
* the counter here, but to prevent another
* thread preempting this thread and decrementing
* the semaphore before this section was
* scheduled back in, we emulate the increment
* and decrement by not incrementing in the
* atomSemPut() and not decrementing here. The
* count remains zero throughout preventing other
* threads preempting before we decrement the
* count again.
*/
}
}
}
else
{
/* Exit critical region */
CRITICAL_END ();
/* Not currently in thread context, can't suspend */
status = ATOM_ERR_CONTEXT;
}
}
else
{
/* timeout == -1, requested not to block and count is zero */
CRITICAL_END();
status = ATOM_WOULDBLOCK;
}
}
else
{
/* Count is non-zero, just decrement it and return to calling thread */
sem->count--;
/* Exit critical region */
CRITICAL_END ();
/* Successful */
status = ATOM_OK;
}
}
return (status);
}
/**
* \b atomTimerDelay
*
* Suspend a thread for the given number of system ticks.
*
* Note that the wakeup time is the number of ticks from the current system
* tick, therefore, for a one tick delay, the thread may be woken up at any
* time between the atomTimerDelay() call and the next system tick. For
* a minimum number of ticks, you should specify minimum number of ticks + 1.
*
* This function can only be called from thread context.
*
* @param[in] ticks Number of system ticks to delay (must be > 0)
*
* @retval ATOM_OK Successful delay
* @retval ATOM_ERR_PARAM Bad parameter (ticks must be non-zero)
* @retval ATOM_ERR_CONTEXT Not called from thread context
*/
uint8_t atomTimerDelay (uint32_t ticks)
{
ATOM_TCB *curr_tcb_ptr;
ATOM_TIMER timer_cb;
DELAY_TIMER timer_data;
CRITICAL_STORE;
uint8_t status;
/* Get the current TCB */
curr_tcb_ptr = atomCurrentContext();
/* Parameter check */
if (ticks == 0)
{
/* Return error */
status = ATOM_ERR_PARAM;
}
/* Check we are actually in thread context */
else if (curr_tcb_ptr == NULL)
{
/* Not currently in thread context, can't suspend */
status = ATOM_ERR_CONTEXT;
}
/* Otherwise safe to proceed */
else
{
/* Protect the system queues */
CRITICAL_START ();
/* Set suspended status for the current thread */
curr_tcb_ptr->suspended = TRUE;
/* Register the timer callback */
/* Fill out the data needed by the callback to wake us up */
timer_data.tcb_ptr = curr_tcb_ptr;
/* Fill out the timer callback request structure */
timer_cb.cb_func = atomTimerDelayCallback;
timer_cb.cb_data = (POINTER)&timer_data;
timer_cb.cb_ticks = ticks;
/* Store the timeout callback details, though we don't use it */
curr_tcb_ptr->suspend_timo_cb = &timer_cb;
/* Register the callback */
if (atomTimerRegister (&timer_cb) != ATOM_OK)
{
/* Exit critical region */
CRITICAL_END ();
/* Timer registration didn't work, won't get a callback */
status = ATOM_ERR_TIMER;
}
else
{
/* Exit critical region */
CRITICAL_END ();
/* Successful timer registration */
status = ATOM_OK;
/* Current thread should now block, schedule in another */
atomSched (FALSE);
}
}
return (status);
}
/**
* \b test_start
*
* Start mutex test.
*
* This test exercises the atomMutexGet() and atomMutexPut() APIs including
* forcing the various error indications which can be returned from the
* APIs to ensure that handling for these corner cases have been correctly
* implemented.
*
* @retval Number of failures
*/
uint32_t test_start (void)
{
int failures;
uint8_t status;
ATOM_TIMER timer_cb;
int count;
/* Default to zero failures */
failures = 0;
/* Test parameter checks */
if (atomMutexGet (NULL, 0) != ATOM_ERR_PARAM)
{
ATOMLOG (_STR("Get param failed\n"));
failures++;
}
if (atomMutexPut (NULL) != ATOM_ERR_PARAM)
{
ATOMLOG (_STR("Put param failed\n"));
failures++;
}
/* Test atomMutexGet() can not be called from interrupt context */
g_result = 0;
if (atomMutexCreate (&mutex1) != ATOM_OK)
{
ATOMLOG (_STR("Error creating test mutex1\n"));
failures++;
}
else
{
/* Fill out the timer callback request structure */
timer_cb.cb_func = testCallback;
timer_cb.cb_data = NULL;
timer_cb.cb_ticks = SYSTEM_TICKS_PER_SEC;
/* Request the timer callback to run in one second */
if (atomTimerRegister (&timer_cb) != ATOM_OK)
{
ATOMLOG (_STR("Error registering timer\n"));
failures++;
}
/* Wait two seconds for g_result to be set indicating success */
else
{
atomTimerDelay (2 * SYSTEM_TICKS_PER_SEC);
if (g_result != 1)
{
ATOMLOG (_STR("Context check failed\n"));
failures++;
}
}
/* Delete the test mutex */
if (atomMutexDelete (&mutex1) != ATOM_OK)
{
ATOMLOG (_STR("Mutex1 delete failed\n"));
failures++;
}
}
/* Create mutex1 which will be owned by us */
if (atomMutexCreate (&mutex1) != ATOM_OK)
{
ATOMLOG (_STR("Error creating test mutex 1\n"));
failures++;
}
/* Create mutex2 which will be owned by another thread */
else if (atomMutexCreate (&mutex2) != ATOM_OK)
{
ATOMLOG (_STR("Error creating test mutex 2\n"));
failures++;
}
/* Create a test thread, the sole purpose of which is to own mutex2 */
g_owned = 0;
if (atomThreadCreate(&tcb[0], TEST_THREAD_PRIO, test_thread_func, 0,
&test_thread_stack[0][TEST_THREAD_STACK_SIZE - 1],
TEST_THREAD_STACK_SIZE) != ATOM_OK)
{
/* Fail */
ATOMLOG (_STR("Error creating test thread 1\n"));
failures++;
}
/* Sleep until the test thread owns mutex2 */
atomTimerDelay (SYSTEM_TICKS_PER_SEC);
if (g_owned == 0)
{
ATOMLOG (_STR("Thread own fail\n"));
failures++;
}
/* Test wait on mutex with timeout - should timeout while owned by another thread */
if ((status = atomMutexGet (&mutex2, SYSTEM_TICKS_PER_SEC)) != ATOM_TIMEOUT)
{
ATOMLOG (_STR("Get %d\n"), status);
failures++;
}
else
{
/* Success */
}
/* Test wait on mutex with no blocking - should return that owned by another thread */
if ((status = atomMutexGet (&mutex2, -1)) != ATOM_WOULDBLOCK)
{
ATOMLOG (_STR("Wouldblock err %d\n"), status);
failures++;
}
/* Test wait on mutex with no blocking when mutex is available */
if (atomMutexGet (&mutex1, -1) != ATOM_OK)
{
ATOMLOG (_STR("Error taking mutex1\n"));
failures++;
}
else
{
/* Relinquish ownership of mutex1 */
if (atomMutexPut (&mutex1) != ATOM_OK)
{
ATOMLOG (_STR("Error posting mutex\n"));
failures++;
}
}
/* Test for lock count overflows with too many gets */
count = 255;
while (count--)
{
if (atomMutexGet (&mutex1, 0) != ATOM_OK)
{
ATOMLOG (_STR("Error getting mutex1\n"));
failures++;
break;
}
}
/* The lock count should overflow this time */
if (atomMutexGet (&mutex1, 0) != ATOM_ERR_OVF)
{
ATOMLOG (_STR("Error tracking overflow\n"));
failures++;
}
else
{
/* Success */
}
/* Delete the test mutexes */
if (atomMutexDelete (&mutex1) != ATOM_OK)
{
ATOMLOG (_STR("Error deleting mutex1\n"));
failures++;
}
if (atomMutexDelete (&mutex2) != ATOM_OK)
{
ATOMLOG (_STR("Error deleting mutex2\n"));
failures++;
}
/* Check thread stack usage (if enabled) */
#ifdef ATOM_STACK_CHECKING
{
uint32_t used_bytes, free_bytes;
int thread;
/* Check all threads */
for (thread = 0; thread < NUM_TEST_THREADS; thread++)
{
/* Check thread stack usage */
if (atomThreadStackCheck (&tcb[thread], &used_bytes, &free_bytes) != ATOM_OK)
{
ATOMLOG (_STR("StackCheck\n"));
failures++;
}
else
{
/* Check the thread did not use up to the end of stack */
if (free_bytes == 0)
{
ATOMLOG (_STR("StackOverflow %d\n"), thread);
failures++;
}
/* Log the stack usage */
#ifdef TESTS_LOG_STACK_USAGE
ATOMLOG (_STR("StackUse:%d\n"), (int)used_bytes);
#endif
}
}
}
#endif
/* Quit */
return failures;
}
/**
* \b test_start
*
* Start mutex test.
*
* This tests the ownership checks of the mutex library. Only threads
* which own a mutex can release it. It should not be possible to
* release a mutex if it is not owned by any thread, is owned by a
* different thread, or at interrupt context. We test here that all
* three cases are trapped.
*
* @retval Number of failures
*/
uint32_t test_start (void)
{
int failures;
ATOM_TIMER timer_cb;
/* Default to zero failures */
failures = 0;
/* Create mutex */
if (atomMutexCreate (&mutex1) != ATOM_OK)
{
ATOMLOG (_STR("Error creating mutex\n"));
failures++;
}
else
{
/* Initialise the shared_data to zero */
shared_data = 0;
/* Attempt to release the mutex when not owned by any thread */
if (atomMutexPut (&mutex1) != ATOM_ERR_OWNERSHIP)
{
ATOMLOG (_STR("Release error\n"));
failures++;
}
/* Create second thread */
else if (atomThreadCreate(&tcb[0], TEST_THREAD_PRIO, test_thread_func, 1,
&test_thread_stack[0][TEST_THREAD_STACK_SIZE - 1],
TEST_THREAD_STACK_SIZE) != ATOM_OK)
{
/* Fail */
ATOMLOG (_STR("Error creating test thread\n"));
failures++;
}
/*
* The second thread has now been created and should take ownership
* of the mutex. We wait a while and check that shared_data has been
* modified, which proves to us that the thread has taken the mutex.
*/
atomTimerDelay (SYSTEM_TICKS_PER_SEC/4);
if (shared_data != 1)
{
ATOMLOG (_STR("Shared data unmodified\n"));
failures++;
}
/* Check successful so far */
if (failures == 0)
{
/*
* Attempt to release the mutex again now that it is owned
* by another thread.
*/
if (atomMutexPut (&mutex1) != ATOM_ERR_OWNERSHIP)
{
ATOMLOG (_STR("Release error 2\n"));
failures++;
}
/* Finally check that the mutex cannot be released from an ISR */
/* Fill out the timer callback request structure */
timer_cb.cb_func = testCallback;
timer_cb.cb_data = NULL;
timer_cb.cb_ticks = SYSTEM_TICKS_PER_SEC;
/* Request the timer callback to run in one second */
if (atomTimerRegister (&timer_cb) != ATOM_OK)
{
ATOMLOG (_STR("Error registering timer\n"));
failures++;
}
/*
* Wait two seconds for shared_date to be set to 2
* indicating success. This happens if the timer
* callback received the expected ownership error
* when attempting to release the mutex.
*/
else
{
atomTimerDelay (2 * SYSTEM_TICKS_PER_SEC);
if (shared_data != 2)
{
ATOMLOG (_STR("Context check failed\n"));
failures++;
}
}
}
/* Delete mutex, test finished */
if (atomMutexDelete (&mutex1) != ATOM_OK)
{
ATOMLOG (_STR("Delete failed\n"));
failures++;
}
}
/* Check thread stack usage (if enabled) */
#ifdef ATOM_STACK_CHECKING
{
uint32_t used_bytes, free_bytes;
int thread;
/* Check all threads */
for (thread = 0; thread < NUM_TEST_THREADS; thread++)
{
/* Check thread stack usage */
if (atomThreadStackCheck (&tcb[thread], &used_bytes, &free_bytes) != ATOM_OK)
{
ATOMLOG (_STR("StackCheck\n"));
failures++;
}
else
{
/* Check the thread did not use up to the end of stack */
if (free_bytes == 0)
{
ATOMLOG (_STR("StackOverflow %d\n"), thread);
failures++;
}
/* Log the stack usage */
#ifdef TESTS_LOG_STACK_USAGE
ATOMLOG (_STR("StackUse:%d\n"), (int)used_bytes);
#endif
}
}
}
#endif
/* Quit */
return failures;
}
/**
* \b test_start
*
* Start timer test.
*
* This test exercises the atomTimerCancel() API, particularly its
* behaviour when there are several timers registered. Four timers
* are registered, two of which are cancelled, and the test confirms
* that only the two which are not cancelled are called back.
*
* @retval Number of failures
*/
uint32_t test_start (void)
{
int failures;
int i;
/* Default to zero failures */
failures = 0;
/* Clear down the ran flag for all four timers */
for (i = 0; i < 4; i++)
{
callback_ran_flag[i] = FALSE;
}
/*
* Fill out four timer request structures. Callbacks are
* requested starting in one second, with the others
* at 1 tick intervals thereafter.
*/
for (i = 0; i < 4; i++)
{
/*
* testCallback() is passed a pointer to the flag it
* should set to notify that it has run.
*/
timer_cb[i].cb_ticks = SYSTEM_TICKS_PER_SEC + i;
timer_cb[i].cb_func = testCallback;
timer_cb[i].cb_data = &callback_ran_flag[i];
}
/* Register all four timers */
for (i = 0; i < 4; i++)
{
if (atomTimerRegister (&timer_cb[i]) != ATOM_OK)
{
ATOMLOG (_STR("TimerReg\n"));
failures++;
}
}
/* Check timers were successfully created */
if (failures == 0)
{
/* Cancel two of the callbacks */
if (atomTimerCancel (&timer_cb[1]) != ATOM_OK)
{
ATOMLOG (_STR("Cancel1\n"));
failures++;
}
if (atomTimerCancel (&timer_cb[2]) != ATOM_OK)
{
ATOMLOG (_STR("Cancel2\n"));
failures++;
}
/* Wait two seconds for callbacks to complete */
if (atomTimerDelay(2 * SYSTEM_TICKS_PER_SEC) != ATOM_OK)
{
ATOMLOG (_STR("Wait\n"));
failures++;
}
else
{
/*
* We should now find that timer callbacks 0 and 3
* have run, but 1 and 2 did not (due to cancellation).
*/
if ((callback_ran_flag[0] != TRUE) || (callback_ran_flag[3] != TRUE)
|| (callback_ran_flag[1] != FALSE) || (callback_ran_flag[2] != FALSE))
{
ATOMLOG (_STR("Cancellations\n"));
failures++;
}
}
}
/* Quit */
return failures;
}
/**
* \b atomMutexGet
*
* Take the lock on a mutex.
*
* This takes ownership of a mutex if it is not currently owned. Ownership
* is held by this thread until a corresponding call to atomMutexPut() by
* the same thread.
*
* Can be called recursively by the original locking thread (owner).
* Recursive calls are counted, and ownership is not relinquished until
* the number of unlock (atomMutexPut()) calls by the owner matches the
* number of lock (atomMutexGet()) calls.
*
* No thread other than the owner can lock or unlock the mutex while it is
* locked by another thread.
*
* Depending on the \c timeout value specified the call will do one of
* the following if the mutex is already locked by another thread:
*
* \c timeout == 0 : Call will block until the mutex is available \n
* \c timeout > 0 : Call will block until available up to the specified timeout \n
* \c timeout == -1 : Return immediately if mutex is locked by another thread \n
*
* If the call needs to block and \c timeout is zero, it will block
* indefinitely until the owning thread calls atomMutexPut() or
* atomMutexDelete() is called on the mutex.
*
* If the call needs to block and \c timeout is non-zero, the call will only
* block for the specified number of system ticks after which time, if the
* thread was not already woken, the call will return with \c ATOM_TIMEOUT.
*
* If the call would normally block and \c timeout is -1, the call will
* return immediately with \c ATOM_WOULDBLOCK.
*
* This function can only be called from thread context. A mutex has the
* concept of an owner thread, so it is never valid to make a mutex call
* from interrupt context when there is no thread to associate with.
*
* @param[in] mutex Pointer to mutex object
* @param[in] timeout Max system ticks to block (0 = forever)
*
* @retval ATOM_OK Success
* @retval ATOM_TIMEOUT Mutex timed out before being woken
* @retval ATOM_WOULDBLOCK Called with timeout == -1 but count is zero
* @retval ATOM_ERR_DELETED Mutex was deleted while suspended
* @retval ATOM_ERR_CONTEXT Not called in thread context and attempted to block
* @retval ATOM_ERR_PARAM Bad parameter
* @retval ATOM_ERR_QUEUE Problem putting the thread on the suspend queue
* @retval ATOM_ERR_TIMER Problem registering the timeout
* @retval ATOM_ERR_OVF The recursive lock count would have overflowed (>255)
*/
uint8_t atomMutexGet (ATOM_MUTEX *mutex, int32_t timeout){
CRITICAL_STORE;
uint8_t status;
MUTEX_TIMER timer_data;
ATOM_TIMER timer_cb;
ATOM_TCB *curr_tcb_ptr;
/* Check parameters */
if (mutex == NULL)
{
/* Bad mutex pointer */
status = ATOM_ERR_PARAM;
}
else
{
/* Get the current TCB */
curr_tcb_ptr = atomCurrentContext();
/* Protect access to the mutex object and OS queues */
CRITICAL_START ();
/**
* Check we are at thread context. Because mutexes have the concept of
* owner threads, it is never valid to call here from an ISR,
* regardless of whether we will block.
*/
if (curr_tcb_ptr == NULL)
{
/* Exit critical region */
CRITICAL_END ();
/* Not currently in thread context, can't suspend */
status = ATOM_ERR_CONTEXT;
}
/* Otherwise if mutex is owned by another thread, block the calling thread */
else if ((mutex->owner != NULL) && (mutex->owner != curr_tcb_ptr))
{
/* If called with timeout >= 0, we should block */
if (timeout >= 0)
{
/* Add current thread to the suspend list on this mutex */
if (tcbEnqueuePriority (&mutex->suspQ, curr_tcb_ptr) != ATOM_OK)
{
/* Exit critical region */
CRITICAL_END ();
/* There was an error putting this thread on the suspend list */
status = ATOM_ERR_QUEUE;
}
else
{
/* Set suspended status for the current thread */
curr_tcb_ptr->suspended = TRUE;
/* Track errors */
status = ATOM_OK;
/* Register a timer callback if requested */
if (timeout)
{
/* Fill out the data needed by the callback to wake us up */
timer_data.tcb_ptr = curr_tcb_ptr;
timer_data.mutex_ptr = mutex;
/* Fill out the timer callback request structure */
timer_cb.cb_func = atomMutexTimerCallback;
timer_cb.cb_data = (POINTER)&timer_data;
timer_cb.cb_ticks = timeout;
/**
* Store the timer details in the TCB so that we can
* cancel the timer callback if the mutex is put
* before the timeout occurs.
*/
curr_tcb_ptr->suspend_timo_cb = &timer_cb;
/* Register a callback on timeout */
if (atomTimerRegister (&timer_cb) != ATOM_OK)
{
/* Timer registration failed */
status = ATOM_ERR_TIMER;
/* Clean up and return to the caller */
(void)tcbDequeueEntry (&mutex->suspQ, curr_tcb_ptr);
curr_tcb_ptr->suspended = FALSE;
curr_tcb_ptr->suspend_timo_cb = NULL;
}
}
/* Set no timeout requested */
else
{
/* No need to cancel timeouts on this one */
curr_tcb_ptr->suspend_timo_cb = NULL;
}
/* Exit critical region */
CRITICAL_END ();
/* Check no errors have occurred */
if (status == ATOM_OK)
{
/**
* Current thread now blocking, schedule in a new
* one. We already know we are in thread context
* so can call the scheduler from here.
*/
atomSched (FALSE);
/**
* Normal atomMutexPut() wakeups will set ATOM_OK status,
* while timeouts will set ATOM_TIMEOUT and mutex
* deletions will set ATOM_ERR_DELETED. */
status = curr_tcb_ptr->suspend_wake_status;
/**
* If we were woken up by another thread relinquishing
* the mutex and handing this thread ownership, then
* the relinquishing thread will set status to ATOM_OK
* and will make this thread the owner. Setting the
* owner before waking the thread ensures that no other
* thread can preempt and take ownership of the mutex
* between this thread being made ready to run, and
* actually being scheduled back in here.
*/
if (status == ATOM_OK)
{
/**
* Since this thread has just gained ownership, the
* lock count is zero and should be incremented
* once for this call.
*/
mutex->count++;
}
}
}
}
else
{
/* timeout == -1, requested not to block and mutex is owned by another thread */
CRITICAL_END();
status = ATOM_WOULDBLOCK;
}
}
else
{
/* Thread is not owned or is owned by us, we can claim ownership */
/* Increment the lock count, checking for count overflow */
if (mutex->count == 255)
{
/* Don't increment, just return error status */
status = ATOM_ERR_OVF;
}
else
{
/* Increment the count and return to the calling thread */
mutex->count++;
/* If the mutex is not locked, mark the calling thread as the new owner */
if (mutex->owner == NULL)
{
mutex->owner = curr_tcb_ptr;
}
/* Successful */
status = ATOM_OK;
}
/* Exit critical region */
CRITICAL_END ();
}
}
return (status);
}