Martine Lenders
8 years ago
committed by
Martine Lenders
9 changed files with 208 additions and 222 deletions
@ -1,159 +0,0 @@
|
||||
/**
|
||||
* Semaphore implemenation |
||||
* |
||||
* Copyright (C) 2013 Freie Universität Berlin |
||||
* |
||||
* This file is subject to the terms and conditions of the GNU Lesser |
||||
* General Public License v2.1. See the file LICENSE in the top level |
||||
* directory for more details. |
||||
* |
||||
* @ingroup posix |
||||
* |
||||
* @{ |
||||
* |
||||
* @file |
||||
* @brief Implementation of semaphores with priority queues |
||||
* |
||||
* @author Christian Mehlis <mehlis@inf.fu-berlin.de> |
||||
* @author René Kijewski <kijewski@inf.fu-berlin.de> |
||||
* |
||||
* @} |
||||
*/ |
||||
|
||||
#include <inttypes.h> |
||||
|
||||
#include "irq.h" |
||||
#include "sched.h" |
||||
#include "tcb.h" |
||||
#include "thread.h" |
||||
|
||||
#define ENABLE_DEBUG (0) |
||||
#include "debug.h" |
||||
|
||||
#include "semaphore.h" |
||||
|
||||
int sem_init(sem_t *sem, int pshared, unsigned int value) |
||||
{ |
||||
(void) pshared; /* nothing to do */ |
||||
|
||||
sem->value = value; |
||||
|
||||
/* waiters for the mutex */ |
||||
sem->queue.first = NULL; |
||||
|
||||
return 0; |
||||
} |
||||
|
||||
int sem_destroy(sem_t *sem) |
||||
{ |
||||
if (sem->queue.first) { |
||||
DEBUG("sem_destroy: %" PRIkernel_pid ": tried to destroy active semaphore.\n", |
||||
sched_active_thread->pid); |
||||
return -1; |
||||
} |
||||
return 0; |
||||
} |
||||
|
||||
sem_t *sem_open(const char *name, int oflag, ...) |
||||
{ |
||||
(void) name; /* named semaphore currently not supported */ |
||||
(void) oflag; |
||||
return SEM_FAILED; |
||||
} |
||||
|
||||
int sem_close(sem_t *sem) |
||||
{ |
||||
(void) sem; /* named semaphore currently not supported */ |
||||
return -1; |
||||
} |
||||
|
||||
int sem_unlink(const char *name) |
||||
{ |
||||
(void) name; /* named semaphore currently not supported */ |
||||
return -1; |
||||
} |
||||
|
||||
int sem_wait(sem_t *sem) |
||||
{ |
||||
while (1) { |
||||
unsigned old_state = disableIRQ(); |
||||
|
||||
unsigned value = sem->value; |
||||
if (value != 0) { |
||||
sem->value = value - 1; |
||||
restoreIRQ(old_state); |
||||
return 1; |
||||
} |
||||
|
||||
/* I'm going blocked */ |
||||
priority_queue_node_t n; |
||||
n.priority = (uint32_t) sched_active_thread->priority; |
||||
n.data = (uintptr_t) sched_active_thread; |
||||
n.next = NULL; |
||||
priority_queue_add(&sem->queue, &n); |
||||
|
||||
DEBUG("sem_wait: %" PRIkernel_pid ": Adding node to mutex queue: prio: %" PRIu32 "\n", |
||||
sched_active_thread->pid, sched_active_thread->priority); |
||||
|
||||
/* scheduler should schedule an other thread, that unlocks the
|
||||
* mutex in the future, when this happens I get scheduled again |
||||
*/ |
||||
sched_set_status((tcb_t*) sched_active_thread, STATUS_MUTEX_BLOCKED); |
||||
restoreIRQ(old_state); |
||||
thread_yield_higher(); |
||||
} |
||||
} |
||||
|
||||
int sem_timedwait(sem_t *sem, const struct timespec *abstime) |
||||
{ |
||||
(void) sem; /* timedwait currently not supported */ |
||||
(void) abstime; |
||||
return -1; /* signal problem */ |
||||
} |
||||
|
||||
int sem_trywait(sem_t *sem) |
||||
{ |
||||
unsigned old_state = disableIRQ(); |
||||
int result; |
||||
|
||||
unsigned value = sem->value; |
||||
if (value == 0) { |
||||
result = -1; |
||||
} |
||||
else { |
||||
result = 0; |
||||
sem->value = value - 1; |
||||
} |
||||
|
||||
restoreIRQ(old_state); |
||||
return result; |
||||
} |
||||
|
||||
int sem_post(sem_t *sem) |
||||
{ |
||||
unsigned old_state = disableIRQ(); |
||||
++sem->value; |
||||
|
||||
priority_queue_node_t *next = priority_queue_remove_head(&sem->queue); |
||||
if (next) { |
||||
tcb_t *next_process = (tcb_t*) next->data; |
||||
DEBUG("sem_post: %" PRIkernel_pid ": waking up %" PRIkernel_pid "\n", |
||||
sched_active_thread->pid, next_process->pid); |
||||
sched_set_status(next_process, STATUS_PENDING); |
||||
|
||||
uint16_t prio = next_process->priority; |
||||
restoreIRQ(old_state); |
||||
sched_switch(prio); |
||||
} |
||||
else { |
||||
restoreIRQ(old_state); |
||||
} |
||||
|
||||
return 1; |
||||
} |
||||
|
||||
int sem_getvalue(sem_t *sem, int *sval) |
||||
{ |
||||
*sval = sem->value; |
||||
return 0; |
||||
} |
||||
@ -0,0 +1,3 @@
|
||||
MODULE = posix_semaphore
|
||||
|
||||
include $(RIOTBASE)/Makefile.base |
||||
@ -0,0 +1,77 @@
|
||||
/*
|
||||
* Copyright (C) 2013 Freie Universität Berlin |
||||
* |
||||
* This file is subject to the terms and conditions of the GNU Lesser |
||||
* General Public License v2.1. See the file LICENSE in the top level |
||||
* directory for more details. |
||||
*/ |
||||
|
||||
/**
|
||||
* @{ |
||||
* |
||||
* @file |
||||
* |
||||
* @author Christian Mehlis <mehlis@inf.fu-berlin.de> |
||||
* @author Martine Lenders <mlenders@inf.fu-berlin.de> |
||||
* @author René Kijewski <kijewski@inf.fu-berlin.de> |
||||
*/ |
||||
|
||||
#include <errno.h> |
||||
#include <inttypes.h> |
||||
|
||||
#include "irq.h" |
||||
#include "sched.h" |
||||
#include "sem.h" |
||||
#include "tcb.h" |
||||
#include "timex.h" |
||||
#include "thread.h" |
||||
#include "vtimer.h" |
||||
|
||||
#define ENABLE_DEBUG (0) |
||||
#include "debug.h" |
||||
|
||||
#include "semaphore.h" |
||||
|
||||
#define USEC_IN_NS (1000) |
||||
|
||||
int sem_timedwait(sem_t *sem, const struct timespec *abstime) |
||||
{ |
||||
timex_t now, timeout = { abstime->tv_sec, abstime->tv_nsec / USEC_IN_NS }; |
||||
int res; |
||||
vtimer_now(&now); |
||||
if (timex_cmp(now, timeout) > 0) { |
||||
errno = ETIMEDOUT; |
||||
return -ETIMEDOUT; |
||||
} |
||||
timeout = timex_sub(timeout, now); |
||||
res = sem_wait_timed(sem, &timeout); |
||||
if (res < 0) { |
||||
errno = -res; |
||||
} |
||||
return res; |
||||
} |
||||
|
||||
int sem_trywait(sem_t *sem) |
||||
{ |
||||
unsigned int old_state, value; |
||||
int result; |
||||
if (sem == NULL) { |
||||
errno = EINVAL; |
||||
return -EINVAL; |
||||
} |
||||
old_state = disableIRQ(); |
||||
value = sem->value; |
||||
if (value == 0) { |
||||
errno = EAGAIN; |
||||
result = -EAGAIN; |
||||
} |
||||
else { |
||||
result = 0; |
||||
sem->value = value - 1; |
||||
} |
||||
|
||||
restoreIRQ(old_state); |
||||
return result; |
||||
} |
||||
|
||||
/** @} */ |
||||
Loading…
Reference in new issue