uvisor_semaphore.c

00001 #include "api/inc/uvisor_semaphore_exports.h"
00002 #include "api/inc/uvisor_exports.h"
00003 #include "api/inc/halt_exports.h"
00004 #include "cmsis_os2.h"
00005 #include "rtx_lib.h"
00006 #include <string.h>
00007 
00008 typedef struct uvisor_semaphore_internal {
00009     osSemaphoreId_t   id;
00010     osSemaphoreAttr_t attr;
00011     osRtxSemaphore_t data;
00012 } UVISOR_ALIGN(4) uvisor_semaphore_internal_t;
00013 
00014 UVISOR_STATIC_ASSERT(UVISOR_SEMAPHORE_INTERNAL_SIZE >= sizeof(UvisorSemaphore), semaphore_size_too_small);
00015 
00016 int __uvisor_semaphore_init(UvisorSemaphore * s, uint32_t max_count, uint32_t initial_count)
00017 {
00018     uvisor_semaphore_internal_t * semaphore = (uvisor_semaphore_internal_t *) s;
00019 
00020     memset(&semaphore->data, 0, sizeof(semaphore->data));
00021     memset(&semaphore->attr, 0, sizeof(semaphore->attr));
00022     semaphore->attr.name = "uvisor_semaphore";
00023     semaphore->attr.cb_size = sizeof(semaphore->data);
00024     semaphore->attr.cb_mem = &semaphore->data;
00025     semaphore->id = osSemaphoreNew(max_count, initial_count, &semaphore->attr);
00026 
00027     /* Error when semaphore->id is NULL */
00028     return semaphore->id == NULL ? UVISOR_ERROR_OUT_OF_STRUCTURES : 0;
00029 }
00030 
00031 int __uvisor_semaphore_pend(UvisorSemaphore * s, uint32_t timeout_ms)
00032 {
00033     uvisor_semaphore_internal_t * semaphore = (uvisor_semaphore_internal_t *) s;
00034 
00035     osStatus_t status = osSemaphoreAcquire(semaphore->id, timeout_ms);
00036 
00037     if (status == osErrorTimeout) {
00038         return UVISOR_ERROR_TIMEOUT;
00039     } else if (status == osErrorParameter) {
00040         return UVISOR_ERROR_INVALID_PARAMETERS;
00041     } else if (status != osOK) {
00042         return -1; /* Other error */
00043     }
00044 
00045     return 0;
00046 }
00047 
00048 int __uvisor_semaphore_post(UvisorSemaphore * s) {
00049     uvisor_semaphore_internal_t * semaphore = (uvisor_semaphore_internal_t *) s;
00050     return osSemaphoreRelease(semaphore->id);
00051 }