diff options
Diffstat (limited to 'src/lib')
-rw-r--r-- | src/lib/lockfile.c | 94 |
1 files changed, 39 insertions, 55 deletions
diff --git a/src/lib/lockfile.c b/src/lib/lockfile.c index 18585417..c5449907 100644 --- a/src/lib/lockfile.c +++ b/src/lib/lockfile.c @@ -36,83 +36,69 @@ #include <sys/stat.h> #define LF_SIZE (sizeof(pid_t)) +#define LF_PROT (PROT_READ | PROT_WRITE) struct lockfile { pid_t * pid; }; -struct lockfile * lockfile_create(void) +static struct lockfile * __lockfile_open(int oflag) { - int fd; - mode_t mask; - struct lockfile * lf = malloc(sizeof(*lf)); - if (lf == NULL) - return NULL; - - mask = umask(0); + int fd; + struct lockfile * lf; - fd = shm_open(SHM_LOCKFILE_NAME, O_CREAT | O_EXCL | O_RDWR, 0666); - if (fd == -1) { - free(lf); - return NULL; - } + lf = malloc(sizeof(*lf)); + if (lf == NULL) + goto fail_lockfile; - umask(mask); + fd = shm_open(SHM_LOCKFILE_NAME, oflag, 0666); + if (fd == -1) + goto fail_shm_open; - if (ftruncate(fd, LF_SIZE - 1) < 0) { - free(lf); - return NULL; - } + if ((oflag & O_CREAT) && ftruncate(fd, LF_SIZE) < 0) + goto fail_truncate; - lf->pid = mmap(NULL, - LF_SIZE, PROT_READ | PROT_WRITE, - MAP_SHARED, - fd, - 0); + lf->pid = mmap(NULL, LF_SIZE, LF_PROT, MAP_SHARED, fd, 0); + if (lf->pid == MAP_FAILED) + goto fail_mmap; close (fd); - if (lf->pid == MAP_FAILED) { - shm_unlink(SHM_LOCKFILE_NAME); - free(lf); - return NULL; - } - - *lf->pid = getpid(); - return lf; + + fail_mmap: + shm_unlink(SHM_LOCKFILE_NAME); + fail_truncate: + close(fd); + fail_shm_open: + free(lf); + fail_lockfile: + return NULL; } -struct lockfile * lockfile_open(void) +struct lockfile * lockfile_create(void) { - int fd; - struct lockfile * lf = malloc(sizeof(*lf)); - if (lf == NULL) - return NULL; + struct lockfile * lf; + mode_t mask; - fd = shm_open(SHM_LOCKFILE_NAME, O_RDWR, 0666); - if (fd < 0) { - free(lf); - return NULL; - } + mask = umask(0); - lf->pid = mmap(NULL, - LF_SIZE, PROT_READ | PROT_WRITE, - MAP_SHARED, - fd, - 0); + lf = __lockfile_open(O_CREAT | O_EXCL | O_RDWR); + if (lf == NULL) + return NULL; - close(fd); + umask(mask); - if (lf->pid == MAP_FAILED) { - shm_unlink(SHM_LOCKFILE_NAME); - free(lf); - return NULL; - } + *lf->pid = getpid(); return lf; } +struct lockfile * lockfile_open(void) +{ + return __lockfile_open(O_RDWR); +} + void lockfile_close(struct lockfile * lf) { assert(lf); @@ -129,11 +115,9 @@ void lockfile_destroy(struct lockfile * lf) if (getpid() != *lf->pid && kill(*lf->pid, 0) == 0) return; - munmap(lf->pid, LF_SIZE); + lockfile_close(lf); shm_unlink(SHM_LOCKFILE_NAME); - - free(lf); } pid_t lockfile_owner(struct lockfile * lf) |