diff options
Diffstat (limited to 'lib/libc/stdlib/atexit.c')
| -rw-r--r-- | lib/libc/stdlib/atexit.c | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/lib/libc/stdlib/atexit.c b/lib/libc/stdlib/atexit.c index a65dae5..1416b47 100644 --- a/lib/libc/stdlib/atexit.c +++ b/lib/libc/stdlib/atexit.c @@ -32,16 +32,28 @@ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. + * + * $FreeBSD$ */ #if defined(LIBC_SCCS) && !defined(lint) static char sccsid[] = "@(#)atexit.c 8.2 (Berkeley) 7/3/94"; #endif /* LIBC_SCCS and not lint */ +#include "namespace.h" #include <stddef.h> #include <stdlib.h> #include <unistd.h> +#include <pthread.h> #include "atexit.h" +#include "un-namespace.h" + +#include "libc_private.h" + +static pthread_mutex_t atexit_mutex = PTHREAD_MUTEX_INITIALIZER; + +#define _MUTEX_LOCK(x) if (__isthreaded) _pthread_mutex_lock(x) +#define _MUTEX_UNLOCK(x) if (__isthreaded) _pthread_mutex_unlock(x) struct atexit *__atexit; /* points to head of LIFO stack */ @@ -55,15 +67,29 @@ atexit(fn) static struct atexit __atexit0; /* one guaranteed table */ register struct atexit *p; + _MUTEX_LOCK(&atexit_mutex); if ((p = __atexit) == NULL) __atexit = p = &__atexit0; - else if (p->ind >= ATEXIT_SIZE) { - if ((p = (struct atexit *)sbrk(sizeof(*p))) == (struct atexit *)-1) + else while (p->ind >= ATEXIT_SIZE) { + struct atexit *old__atexit; + old__atexit = __atexit; + _MUTEX_UNLOCK(&atexit_mutex); + if ((p = (struct atexit *)malloc(sizeof(*p))) == NULL) return (-1); + _MUTEX_LOCK(&atexit_mutex); + if (old__atexit != __atexit) { + /* Lost race, retry operation */ + _MUTEX_UNLOCK(&atexit_mutex); + free(p); + _MUTEX_LOCK(&atexit_mutex); + p = __atexit; + continue; + } p->ind = 0; p->next = __atexit; __atexit = p; } p->fns[p->ind++] = fn; + _MUTEX_UNLOCK(&atexit_mutex); return (0); } |
