#include <stddef.h>
#include <limits.h>
#include <sys/param.h>
+#include <stdbool.h>
#include "gcc-compat.h"
#include "str.h"
return ret;
}
-static inline int get_key_or_die(char *config_file)
+static int get_key_or_die(const char *config_file)
{
int ret;
struct stat statbuf;
static int mutex_lock(int id)
{
struct sembuf sops[4];
- int ret;
DSS_DEBUG_LOG(("locking\n"));
sops[3].sem_op = 1;
sops[3].sem_flg = SEM_UNDO | IPC_NOWAIT;
- ret = do_semop(id, sops, 4);
- if (ret < 0)
- return -ERRNO_TO_DSS_ERROR(errno);
- return 1;
+ return do_semop(id, sops, 4);
}
-static int mutex_try_lock(int id)
+static bool mutex_is_locked(int id)
{
- struct sembuf sops[2];
+ struct sembuf sops;
int ret;
DSS_DEBUG_LOG(("trying to lock\n"));
- sops[0].sem_num = 0;
- sops[0].sem_op = 0;
- sops[0].sem_flg = SEM_UNDO | IPC_NOWAIT;
+ sops.sem_num = 0;
+ sops.sem_op = 0;
+ sops.sem_flg = SEM_UNDO | IPC_NOWAIT;
- sops[1].sem_num = 0;
- sops[1].sem_op = 1;
- sops[1].sem_flg = SEM_UNDO | IPC_NOWAIT;
-
- ret = do_semop(id, sops, 2);
+ ret = do_semop(id, &sops, 1);
if (ret < 0)
- return -ERRNO_TO_DSS_ERROR(errno);
- return 1;
+ return true;
+ return false;
}
int lock_dss(char *config_file)
{
int ret, semid, key = get_key_or_die(config_file);
+ if (pid)
+ *pid = 0;
ret = mutex_get(key, 0);
if (ret < 0)
return ret;
ret = semctl(semid, 1, GETPID);
if (ret < 0)
return -E_NOT_RUNNING;
- *pid = ret;
- ret = mutex_try_lock(semid);
- if (ret >= 0)
- return -E_NOT_RUNNING;
- return 1;
+ if (pid)
+ *pid = ret;
+ return mutex_is_locked(semid)? 1 : -E_NOT_RUNNING;
}