// FOSA(Frescor Operating System Adaptation layer)
//================================================
-#include <fosa.h>
-
+#include "fosa_mutexes_and_condvars.h"
/*******************************************************
* Mutexes with priority/bandwidth inheritance
******************************************************/
-
+/**
+ * fosa_mutex_init()
+ *
+ * Initialize a frsh mutex
+ *
+ * The mutex pointed to by mutex is initialized as a mutex using
+ * the priority ceiling protocol. A priority ceiling of prioceiling
+ * is assigned to this mutex.
+ *
+ * Returns 0 if successful; otherwise it returns an error code:
+ * EINVAL: the value of prioceiling is invalid
+ * EAGAIN: the system lacked the necessary resources to create the mutex
+ * ENOMEM: Insufficient memory exists to initialize the mutex
+ * EBUSY: The system has detected an attempt to reinitialize the mutex
+ **/
int fosa_mutex_init(fosa_mutex_t *mutex, int prioceiling)
{
- //pthread_mutexattr_t mutex_attr;
-
- /* prioceiling serves as a flag */
- /* if (prioceiling) {
- pthread_mutexattr_init(&mutex_attr);
- pthread_mutexattr_setprotocol(&mutex_attr, PTHREAD_PRIO_INHERIT);
-
- return pthread_mutex_init(mutex, &mutex_attr);
- } else */
- return pthread_mutex_init(mutex, NULL);
+ int error;
+ pthread_mutexattr_t attr;
+
+ if ((error = pthread_mutexattr_init(&attr)) != 0)
+ return error;
+
+ if ((error = pthread_mutexattr_setprotocol(&attr, PTHREAD_PRIO_INHERIT)) != 0)
+ return error;
+
+ return pthread_mutex_init(mutex, &attr);
}
+/**
+ * fosa_mutex_destroy()
+ *
+ * Destroy a frsh mutex
+ *
+ * The mutex pointed to by mutex is destroyed
+ *
+ * Returns 0 if successful; otherwise it returns an error code:
+ * EINVAL: the value of mutex is invalid
+ * EBUSY: The mutex is in use (is locked)
+ **/
int fosa_mutex_destroy(fosa_mutex_t *mutex)
{
return pthread_mutex_destroy(mutex);
}
+/**
+ * fosa_mutex_set_prioceiling()
+ *
+ * Dynamically set the priority ceiling of a mutex
+ *
+ * Since in this implementation we use BandWidth Inheritance defining the
+ * ceiling of a mutex is meaningless, and so the function always returns
+ * EINVAL
+ **/
int fosa_mutex_set_prioceiling(fosa_mutex_t *mutex,
- int new_ceiling,
- int *old_ceiling)
+ int new_ceiling,
+ int *old_ceiling)
{
- return -1;
+ return -EINVAL;
}
+/**
+ * fosa_mutex_get_prioceiling()
+ *
+ * Dynamically get the priority ceiling of a mutex
+ *
+ * Since in this implementation we use BandWidth Inheritance defining the
+ * ceiling of a mutex is meaningless, and so the function always returns
+ * EINVAL
+ **/
int fosa_mutex_get_prioceiling(const fosa_mutex_t *mutex, int *ceiling)
{
- return -1;
+ return -EINVAL;
}
+/**
+ * fosa_mutex_lock()
+ *
+ * Lock a mutex
+ *
+ * This function locks the mutex specified by mutex. If it is already
+ * locked, the calling thread blocks until the mutex becomes
+ * available. The operation returns with the mutex in the locked
+ * state, with the calling thread as its owner.
+ *
+ * Returns 0 if successful; otherwise it returns an error code:
+ * EINVAL: the value of mutex is invalid, or the priority of the
+ * calling thread is higher than the priority ceiling of the mutex
+ * EDEADLK: the current thread already owns this mutex
+ **/
int fosa_mutex_lock(fosa_mutex_t *mutex)
{
return pthread_mutex_lock(mutex);
}
+/**
+ * fosa_mutex_trylock()
+ *
+ * Try locking a mutex
+ *
+ * This function is identical to fosa_mutex_lock() except that if the
+ * mutex is already locked the call returns immediately with an error
+ * indication.
+ *
+ * Returns 0 if successful; otherwise it returns an error code:
+ * EINVAL: the value of mutex is invalid, or the priority of the
+ * calling thread is higher than the priority ceiling of the mutex
+ * EBUSY: the mutex was already locked
+ **/
int fosa_mutex_trylock(fosa_mutex_t *mutex)
{
return pthread_mutex_trylock(mutex);
}
+/**
+ * fosa_mutex_unlock()
+ *
+ * Unlock a mutex
+ *
+ * This function must be called by the owner of the mutex referenced
+ * by mutex, to unlock it. If there are threads blocked on the mutex
+ * the mutex becomes available and the highest priority thread is
+ * awakened to acquire the mutex.
+ *
+ * Returns 0 if successful; otherwise it returns an error code:
+ * EINVAL: the value of mutex is invalid
+ * EPERM: the calling thread is not the owner of the mutex
+ **/
int fosa_mutex_unlock(fosa_mutex_t *mutex)
{
return pthread_mutex_unlock(mutex);
* Condition variables
*********************/
+/**
+ * fosa_cond_init()
+ *
+ * Initiatize a condition variable
+ *
+ * The condition variable referenced by cond is initialized with
+ * the attributes required by the FOSA implementation.
+ *
+ * Returns 0 if successful; otherwise it returns an error code:
+ * EAGAIN: the system lacked the necessary resources to create the
+ * condition variable
+ * ENOMEM: Insufficient memory exists to initialize the condition variable
+ * EBUSY: The system has detected an attempt to reinitialize the
+ * condition variable
+ **/
int fosa_cond_init(fosa_cond_t *cond)
{
return pthread_cond_init(cond, NULL);
}
+/**
+ * fosa_cond_destroy()
+ *
+ * Destroy a condition variable
+ *
+ * The condition variable pointed to by cond is destroyed
+ *
+ * Returns 0 if successful; otherwise it returns an error code:
+ * EINVAL: the value of cond is invalid
+ * EBUSY: The condition variable is in use (a thread is waiting on it)
+ **/
int fosa_cond_destroy(fosa_cond_t *cond)
{
return pthread_cond_destroy(cond);
}
+/**
+ * fosa_cond_signal()
+ *
+ * Signal a condition variable
+ *
+ * This call unblocks at least one of the threads that are waiting on
+ * the condition variable referenced by cond. If there are no threads
+ * waiting, the function has no effect
+ *
+ * Returns 0 if successful; otherwise it returns an error code:
+ * EINVAL: the value of cond is invalid
+ **/
int fosa_cond_signal(fosa_cond_t *cond)
{
return pthread_cond_signal(cond);
}
+/**
+ * fosa_cond_broadcast()
+ *
+ * Broadcast a condition variable
+ *
+ * This call unblocks all of the threads that are waiting on the
+ * condition variable referenced by cond. If there are no threads
+ * waiting, the function has no effect.
+ *
+ * Returns 0 if successful; otherwise it returns an error code:
+ * EINVAL: the value of cond is invalid
+ **/
int fosa_cond_broadcast(fosa_cond_t *cond)
{
return pthread_cond_broadcast(cond);
}
+/**
+ * fosa_cond_wait()
+ *
+ * Wait at a condition variable
+ *
+ * This call is used to block on the condition variable referenced by
+ * cond. It shall be called with the mutex referenced by mutex
+ * locked. The function releases the mutex and blocks the calling
+ * thread until the condition is signalled by some other thread and
+ * the calling thread is awakened. Then it locks the mutex and
+ * returns with the mutex locked by the calling thread.
+ *
+ * Returns 0 if successful; otherwise it returns an error code:
+ * EINVAL: the value of cond or mutex is invalid, or different
+ * mutexes were used for concurrent wait operations on cond, or
+ * the mutex was not owned by the calling thread
+ **/
int fosa_cond_wait(fosa_cond_t *cond, fosa_mutex_t *mutex)
{
return pthread_cond_wait(cond, mutex);
}
+/**
+ * fosa_cond_timedwait()
+ *
+ * Wait at a condition variable, with a timeout
+ *
+ * This function is equal to fosa_cond_wait(), except that the maximum
+ * wait time is limited to the absolute time referenced by abstime, as
+ * measured by the FOSA_CLOCK_ABSOLUTE clock.
+ *
+ * Returns 0 if successful; otherwise it returns an error code:
+ * EINVAL: the value of cond or mutex or abstime is invalid, or different
+ * mutexes were used for concurrent wait operations on cond, or
+ * the mutex was not owned by the calling thread
+ * ETIMEDOUT: the timeout expired
+ **/
int fosa_cond_timedwait(fosa_cond_t *cond,
fosa_mutex_t *mutex,
const struct timespec *abstime)
{
return pthread_cond_timedwait(cond, mutex, abstime);
}
-
projects / frescor / fosa.git / blobdiff