X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;ds=inline;f=src%2Fthread%2Fsem_open.c;h=0ad29de96cc1667f3a6d629f5da4104b56ede9d6;hb=7be59733d71ada3a32a98622507399253f1d5e48;hp=08f98c25a3fa270be7235df68a0b1444905e7eb2;hpb=bf258341b71711461ce19891674d43c135827d0e;p=musl

diff --git a/src/thread/sem_open.c b/src/thread/sem_open.c
index 08f98c25..0ad29de9 100644
--- a/src/thread/sem_open.c
+++ b/src/thread/sem_open.c
@@ -11,16 +11,21 @@
 #include <sys/stat.h>
 #include <stdlib.h>
 #include <pthread.h>
-#include "libc.h"
+#include "lock.h"
+#include "fork_impl.h"
 
-char *__shm_mapname(const char *, char *);
+#define malloc __libc_malloc
+#define calloc __libc_calloc
+#define realloc undef
+#define free undef
 
 static struct {
 	ino_t ino;
 	sem_t *sem;
 	int refcnt;
 } *semtab;
-static int lock[2];
+static volatile int lock[1];
+volatile int *const __sem_open_lockptr = lock;
 
 #define FLAGS (O_RDWR|O_NOFOLLOW|O_CLOEXEC|O_NONBLOCK)
 
@@ -29,7 +34,7 @@ sem_t *sem_open(const char *name, int flags, ...)
 	va_list ap;
 	mode_t mode;
 	unsigned value;
-	int fd, i, e, slot, first=1, cnt;
+	int fd, i, e, slot, first=1, cnt, cs;
 	sem_t newsem;
 	void *map;
 	char tmp[64];
@@ -67,11 +72,13 @@ sem_t *sem_open(const char *name, int flags, ...)
 
 	flags &= (O_CREAT|O_EXCL);
 
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+
 	/* Early failure check for exclusive open; otherwise the case
 	 * where the semaphore already exists is expensive. */
 	if (flags == (O_CREAT|O_EXCL) && access(name, F_OK) == 0) {
 		errno = EEXIST;
-		return SEM_FAILED;
+		goto fail;
 	}
 
 	for (;;) {
@@ -80,19 +87,19 @@ sem_t *sem_open(const char *name, int flags, ...)
 		if (flags != (O_CREAT|O_EXCL)) {
 			fd = open(name, FLAGS);
 			if (fd >= 0) {
-				if ((map = mmap(0, sizeof(sem_t), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) == MAP_FAILED ||
-				    fstat(fd, &st) < 0) {
+				if (fstat(fd, &st) < 0 ||
+				    (map = mmap(0, sizeof(sem_t), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) == MAP_FAILED) {
 					close(fd);
-					return SEM_FAILED;
+					goto fail;
 				}
 				close(fd);
 				break;
 			}
 			if (errno != ENOENT)
-				return SEM_FAILED;
+				goto fail;
 		}
 		if (!(flags & O_CREAT))
-			return SEM_FAILED;
+			goto fail;
 		if (first) {
 			first = 0;
 			va_start(ap, flags);
@@ -101,7 +108,7 @@ sem_t *sem_open(const char *name, int flags, ...)
 			va_end(ap);
 			if (value > SEM_VALUE_MAX) {
 				errno = EINVAL;
-				return SEM_FAILED;
+				goto fail;
 			}
 			sem_init(&newsem, 1, value);
 		}
@@ -112,23 +119,24 @@ sem_t *sem_open(const char *name, int flags, ...)
 		fd = open(tmp, O_CREAT|O_EXCL|FLAGS, mode);
 		if (fd < 0) {
 			if (errno == EEXIST) continue;
-			return SEM_FAILED;
+			goto fail;
 		}
 		if (write(fd, &newsem, sizeof newsem) != sizeof newsem || fstat(fd, &st) < 0 ||
 		    (map = mmap(0, sizeof(sem_t), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) == MAP_FAILED) {
 			close(fd);
 			unlink(tmp);
-			return SEM_FAILED;
+			goto fail;
 		}
 		close(fd);
-		if (link(tmp, name) == 0) break;
-		e = errno;
+		e = link(tmp, name) ? errno : 0;
 		unlink(tmp);
+		if (!e) break;
+		munmap(map, sizeof(sem_t));
 		/* Failure is only fatal when doing an exclusive open;
 		 * otherwise, next iteration will try to open the
 		 * existing file. */
 		if (e != EEXIST || flags == (O_CREAT|O_EXCL))
-			return SEM_FAILED;
+			goto fail;
 	}
 
 	/* See if the newly mapped semaphore is already mapped. If
@@ -138,16 +146,23 @@ sem_t *sem_open(const char *name, int flags, ...)
 	for (i=0; i<SEM_NSEMS_MAX && semtab[i].ino != st.st_ino; i++);
 	if (i<SEM_NSEMS_MAX) {
 		munmap(map, sizeof(sem_t));
-		semtab[i].refcnt++;
-		UNLOCK(lock);
-		return semtab[i].sem;
+		semtab[slot].sem = 0;
+		slot = i;
+		map = semtab[i].sem;
 	}
-	semtab[slot].refcnt = 1;
+	semtab[slot].refcnt++;
 	semtab[slot].sem = map;
 	semtab[slot].ino = st.st_ino;
 	UNLOCK(lock);
-
+	pthread_setcancelstate(cs, 0);
 	return map;
+
+fail:
+	pthread_setcancelstate(cs, 0);
+	LOCK(lock);
+	semtab[slot].sem = 0;
+	UNLOCK(lock);
+	return SEM_FAILED;
 }
 
 int sem_close(sem_t *sem)
@@ -155,10 +170,12 @@ int sem_close(sem_t *sem)
 	int i;
 	LOCK(lock);
 	for (i=0; i<SEM_NSEMS_MAX && semtab[i].sem != sem; i++);
-	if (!--semtab[i].refcnt) {
-		semtab[i].sem = 0;
-		semtab[i].ino = 0;
+	if (--semtab[i].refcnt) {
+		UNLOCK(lock);
+		return 0;
 	}
+	semtab[i].sem = 0;
+	semtab[i].ino = 0;
 	UNLOCK(lock);
 	munmap(sem, sizeof *sem);
 	return 0;