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posix_semaphore: make API POSIX compliant

cc430
Martine Lenders 7 years ago committed by Martine Lenders
parent
commit
45b30a8e91
  1. 151
      sys/posix/include/semaphore.h
  2. 11
      sys/posix/semaphore/posix_semaphore.c
  3. 2
      tests/posix_semaphore/main.c

151
sys/posix/include/semaphore.h

@ -40,7 +40,7 @@ typedef sema_t sem_t;
#define SEM_FAILED ((sem_t *) 0)
/**
* @brief Initialize semaphore.
* @brief Initialize an unnamed semaphore.
*
* @see <a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_init.html">
* The Open Group Base Specifications Issue 7, sem_init()
@ -58,13 +58,108 @@ typedef sema_t sem_t;
* @param[in] value Value to set.
*
* @return 0 on success.
* @return -EINVAL, if semaphore is invalid.
* @return -1, on error and errno set to indicate the error.
*/
#define sem_init(sem, pshared, value) sema_create((sema_t *)(sem), (value))
static inline int sem_init(sem_t *sem, int pshared, unsigned value)
{
int res = sema_create((sema_t *)sem, value);
(void)pshared;
if (res < 0) {
errno = -res;
return -1;
}
return 0;
}
/**
* @brief destroy an unnamed semaphore
*
* @see <a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_destroy.html">
* The Open Group Base Specifications Issue 7, sem_destroy()
* </a>
*
* The sem_destroy() function shall destroy the unnamed semaphore indicated by @p sem. Only a
* semaphore that was created using sem_init() may be destroyed using sem_destroy(); the effect of
* calling sem_destroy() with a named semaphore is undefined. The effect of subsequent use of the
* semaphore @p sem is undefined until sem is reinitialized by another call to sem_init().
*
* It is safe to destroy an initialized semaphore upon which no threads are currently blocked.
* The effect of destroying a semaphore upon which other threads are currently blocked is
* undefined.
*
* @param sem A semaphore.
*
* @return 0 on success.
* @return -1, on error and errno set to indicate the error.
*/
static inline int sem_destroy(sem_t *sem)
{
int res = sema_destroy((sema_t *)sem);
if (res < 0) {
errno = -res;
return -1;
}
return 0;
}
/**
* @brief Unlock a semaphore.
*
* @see <a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_post.html">
* The Open Group Base Specifications Issue 7, sem_post()
* </a>
*
* The sem_post() function shall unlock the semaphore referenced by @p sem by performing a
* semaphore unlock operation on that semaphore.
*
* If the semaphore value resulting from this operation is positive, then no threads were blocked
* waiting for the semaphore to become unlocked; the semaphore value is simply incremented.
*
* If the value of the semaphore resulting from this operation is zero, then one of the threads
* blocked waiting for the semaphore shall be allowed to return successfully from its call to
* sem_wait().
*
* @param sem A semaphore
*
* @return 0 on success.
* @return -1, on error and errno set to indicate the error.
*/
static inline int sem_post(sem_t *sem)
{
int res = sema_post((sema_t *)sem);
if (res < 0) {
errno = -res;
return -1;
}
return 0;
}
#define sem_destroy(sem) sema_destroy((sema_t *)(sem))
#define sem_post(sem) sema_post((sema_t *)(sem))
#define sem_wait(sem) sema_wait((sema_t *)(sem))
/**
* @brief Lock a semaphore.
*
* @see <a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_wait.html">
* The Open Group Base Specifications Issue 7, sem_wait()
* </a>
*
* The sem_wait() function shall lock the semaphore referenced by @p sem by performing a semaphore
* lock operation on that semaphore. If the semaphore value is currently zero, then the calling
* thread shall not return from the call to sem_wait() until it either locks the semaphore or the
* call is interrupted by a signal.
*
* @param sem A semaphore.
*
* @return 0 on success.
* @return -1, on error and errno set to indicate the error.
*/
static inline int sem_wait(sem_t *sem)
{
int res = sema_wait((sema_t *)sem);
if (res < 0) {
errno = -res;
return -1;
}
return 0;
}
/**
* @brief Open a named semaphore @p name with open flags @p oflag.
@ -80,7 +175,13 @@ typedef sema_t sem_t;
*
* @return Always @ref SEM_FAILED, since it is not implemented currently.
*/
#define sem_open(name, oflag, ...) (SEM_FAILED)
static inline sem_t *sem_open(const char *name, int oflag, ...)
{
(void)name;
(void)oflag;
errno = ENOMEM;
return SEM_FAILED;
}
/**
* @brief Close descriptor for named semaphore @p sem.
@ -95,7 +196,12 @@ typedef sema_t sem_t;
*
* @return Always -1, since it is not implemented currently.
*/
#define sem_close(sem) (-1)
static inline int sem_close(sem_t *sem)
{
(void)sem;
errno = EINVAL;
return -1;
}
/**
* @brief Remove named semaphore @p name.
@ -110,7 +216,12 @@ typedef sema_t sem_t;
*
* @return Always -1, since it is not implemented currently.
*/
#define sem_unlink(name) (-1)
static inline int sem_unlink(const char *name)
{
(void)name;
errno = ENOENT;
return -1;
}
/**
* @brief Similar to `sem_wait' but wait only until @p abstime.
@ -129,15 +240,13 @@ typedef sema_t sem_t;
* this value) the timeout for the wait shall expire. If the value specified
* has already passed the timeout expires immediately.
*
* @return 0 on success
* @return -EINVAL, if semaphore is invalid.
* @return -ETIMEDOUT, if the semaphore times out.
* @return -ECANCELED, if the semaphore was destroyed.
* @return 0 on success.
* @return -1, on error and errno set to indicate the error.
*/
int sem_timedwait(sem_t *sem, const struct timespec *abstime);
/**
* @brief Test whether SEM is posted.
* @brief Test whether @p sem is posted.
*
* @see <a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_trywait.html">
* The Open Group Base Specifications Issue 7, sem_trywait()
@ -145,14 +254,13 @@ int sem_timedwait(sem_t *sem, const struct timespec *abstime);
*
* @param[in] sem Semaphore to try to wait on
*
* @return 0 on success
* @return -EINVAL, if semaphore is invalid.
* @return -EAGAIN, if the semaphore was already locked.
* @return 0 on success.
* @return -1, on error and errno set to indicate the error.
*/
int sem_trywait(sem_t *sem);
/**
* @brief Get current value of SEM and store it in *SVAL.
* @brief Get current value of @p sem and store it in @p sval.
*
* @see <a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_getvalue.html">
* The Open Group Base Specifications Issue 7, sem_getvalue()
@ -161,8 +269,8 @@ int sem_trywait(sem_t *sem);
* @param[in] sem Semaphore to get the value from.
* @param[out] sval Place where value goes to.
*
* @return 0 on success
* @return -EINVAL, if semaphore is invalid.
* @return 0 on success.
* @return -1, on error and errno set to indicate the error.
*/
static inline int sem_getvalue(sem_t *sem, int *sval)
{
@ -170,7 +278,8 @@ static inline int sem_getvalue(sem_t *sem, int *sval)
*sval = (int)sem->value;
return 0;
}
return -EINVAL;
errno = EINVAL;
return -1;
}
#ifdef __cplusplus

11
sys/posix/semaphore/posix_semaphore.c

@ -39,14 +39,15 @@ int sem_timedwait(sem_t *sem, const struct timespec *abstime)
vtimer_now(&now);
if (timex_cmp(now, timeout) > 0) {
errno = ETIMEDOUT;
return -ETIMEDOUT;
return -1;
}
timeout = timex_sub(timeout, now);
res = sema_wait_timed(sem, &timeout);
res = sema_wait_timed((sema_t *)sem, &timeout);
if (res < 0) {
errno = -res;
return -1;
}
return res;
return 0;
}
int sem_trywait(sem_t *sem)
@ -55,13 +56,13 @@ int sem_trywait(sem_t *sem)
int result;
if (sem == NULL) {
errno = EINVAL;
return -EINVAL;
return -1;
}
old_state = disableIRQ();
value = sem->value;
if (value == 0) {
errno = EAGAIN;
result = -EAGAIN;
result = -1;
}
else {
result = 0;

2
tests/posix_semaphore/main.c

@ -23,11 +23,11 @@
*/
#include <stdio.h>
#include <semaphore.h>
#include "msg.h"
#include "timex.h"
#include "thread.h"
#include "semaphore.h"
#include "vtimer.h"
#define SEMAPHORE_MSG_QUEUE_SIZE (8)

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