4_posix_sem.tgz

#include <stdio.h> #include <fcntl.h> #include <sys/types.h> #include <sys/stat.h> #include <errno.h> #include <sys/mman.h> #include <time.h> #include <string.h> #include "shmipc.h" void clear_exist_sem(sem_t *sem) { int semval; sem_getvalue(sem, &semval); printf("========%d=======\n", semval); while (semval-- > 0) { sem_wait(sem); } } int nms_shm_get(char *shm_file, void **shm, int mem_len) { int fd; fd = shm_open(shm_file, O_RDWR, 0); if (fd < 0) { printf("shm_open <%s> failed: %s\n", shm_file, strerror(errno)); return -1; } ftruncate(fd, mem_len); *shm = mmap(NULL, mem_len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); if (MAP_FAILED == *shm) { printf("mmap: %s\n", strerror(errno)); return -1; } return 0; } int main(int argc, const char *argv[]) { sem_t *sem_consumer = NULL, *sem_productor = NULL; struct timespec timeout; int ret; char *sharememory = NULL; sem_t *sem_mutex; sem_consumer = sem_open(SEM_CONSUMER_FILE, O_RDWR); if (SEM_FAILED == sem_consumer) { printf("sem_open <%s>: %s\n", SEM_CONSUMER_FILE, strerror(errno)); return -1; } sem_productor = sem_open(SEM_PRODUCTOR_FILE, O_RDWR); if (SEM_FAILED == sem_productor) { printf("sem_open <%s>: %s\n", SEM_PRODUCTOR_FILE, strerror(errno)); return -1; } //clear_exist_sem(sem_productor); SLN_MUTEX_SHM_LOCK(SEM_MUTEX, sem_mutex); nms_shm_get(SHM_FILE, (void **)&sharememory, SHM_MAX_LEN); printf("sharememory: %s\n", sharememory); SLN_MUTEX_SHM_UNLOCK(sem_mutex); sem_post(sem_consumer); printf("Post...\n"); sem_wait(sem_productor); /* timeout.tv_sec = time(NULL) + SEM_TIMEOUT_SEC; timeout.tv_nsec = 0; ret = sem_timedwait(sem_productor, &timeout); if (ret < 0) { printf("sem_timedwait: %s\n", strerror(errno)); } */ printf("Get response...\n"); sem_close(sem_consumer); sem_close(sem_productor); return 0; }