| Index: fusl/src/thread/sem_open.c
|
| diff --git a/fusl/src/thread/sem_open.c b/fusl/src/thread/sem_open.c
|
| index fda0acd35c717992e44b4c5191e6f400d1190532..f8ce96ad11d1b52107bf982c6695cfed768f7ca1 100644
|
| --- a/fusl/src/thread/sem_open.c
|
| +++ b/fusl/src/thread/sem_open.c
|
| @@ -13,163 +13,169 @@
|
| #include <pthread.h>
|
| #include "libc.h"
|
|
|
| -char *__shm_mapname(const char *, char *);
|
| +char* __shm_mapname(const char*, char*);
|
|
|
| static struct {
|
| - ino_t ino;
|
| - sem_t *sem;
|
| - int refcnt;
|
| -} *semtab;
|
| + ino_t ino;
|
| + sem_t* sem;
|
| + int refcnt;
|
| +} * semtab;
|
| static volatile int lock[2];
|
|
|
| -#define FLAGS (O_RDWR|O_NOFOLLOW|O_CLOEXEC|O_NONBLOCK)
|
| +#define FLAGS (O_RDWR | O_NOFOLLOW | O_CLOEXEC | O_NONBLOCK)
|
|
|
| -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, cs;
|
| - sem_t newsem;
|
| - void *map;
|
| - char tmp[64];
|
| - struct timespec ts;
|
| - struct stat st;
|
| - char buf[NAME_MAX+10];
|
| +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, cs;
|
| + sem_t newsem;
|
| + void* map;
|
| + char tmp[64];
|
| + struct timespec ts;
|
| + struct stat st;
|
| + char buf[NAME_MAX + 10];
|
|
|
| - if (!(name = __shm_mapname(name, buf)))
|
| - return SEM_FAILED;
|
| + if (!(name = __shm_mapname(name, buf)))
|
| + return SEM_FAILED;
|
|
|
| - LOCK(lock);
|
| - /* Allocate table if we don't have one yet */
|
| - if (!semtab && !(semtab = calloc(sizeof *semtab, SEM_NSEMS_MAX))) {
|
| - UNLOCK(lock);
|
| - return SEM_FAILED;
|
| - }
|
| + LOCK(lock);
|
| + /* Allocate table if we don't have one yet */
|
| + if (!semtab && !(semtab = calloc(sizeof *semtab, SEM_NSEMS_MAX))) {
|
| + UNLOCK(lock);
|
| + return SEM_FAILED;
|
| + }
|
|
|
| - /* Reserve a slot in case this semaphore is not mapped yet;
|
| - * this is necessary because there is no way to handle
|
| - * failures after creation of the file. */
|
| - slot = -1;
|
| - for (cnt=i=0; i<SEM_NSEMS_MAX; i++) {
|
| - cnt += semtab[i].refcnt;
|
| - if (!semtab[i].sem && slot < 0) slot = i;
|
| - }
|
| - /* Avoid possibility of overflow later */
|
| - if (cnt == INT_MAX || slot < 0) {
|
| - errno = EMFILE;
|
| - UNLOCK(lock);
|
| - return SEM_FAILED;
|
| - }
|
| - /* Dummy pointer to make a reservation */
|
| - semtab[slot].sem = (sem_t *)-1;
|
| - UNLOCK(lock);
|
| + /* Reserve a slot in case this semaphore is not mapped yet;
|
| + * this is necessary because there is no way to handle
|
| + * failures after creation of the file. */
|
| + slot = -1;
|
| + for (cnt = i = 0; i < SEM_NSEMS_MAX; i++) {
|
| + cnt += semtab[i].refcnt;
|
| + if (!semtab[i].sem && slot < 0)
|
| + slot = i;
|
| + }
|
| + /* Avoid possibility of overflow later */
|
| + if (cnt == INT_MAX || slot < 0) {
|
| + errno = EMFILE;
|
| + UNLOCK(lock);
|
| + return SEM_FAILED;
|
| + }
|
| + /* Dummy pointer to make a reservation */
|
| + semtab[slot].sem = (sem_t*)-1;
|
| + UNLOCK(lock);
|
|
|
| - flags &= (O_CREAT|O_EXCL);
|
| + flags &= (O_CREAT | O_EXCL);
|
|
|
| - pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
|
| + 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;
|
| - goto fail;
|
| - }
|
| + /* 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;
|
| + goto fail;
|
| + }
|
|
|
| - for (;;) {
|
| - /* If exclusive mode is not requested, try opening an
|
| - * existing file first and fall back to creation. */
|
| - if (flags != (O_CREAT|O_EXCL)) {
|
| - fd = open(name, FLAGS);
|
| - if (fd >= 0) {
|
| - if (fstat(fd, &st) < 0 ||
|
| - (map = mmap(0, sizeof(sem_t), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) == MAP_FAILED) {
|
| - close(fd);
|
| - goto fail;
|
| - }
|
| - close(fd);
|
| - break;
|
| - }
|
| - if (errno != ENOENT)
|
| - goto fail;
|
| - }
|
| - if (!(flags & O_CREAT))
|
| - goto fail;
|
| - if (first) {
|
| - first = 0;
|
| - va_start(ap, flags);
|
| - mode = va_arg(ap, mode_t) & 0666;
|
| - value = va_arg(ap, unsigned);
|
| - va_end(ap);
|
| - if (value > SEM_VALUE_MAX) {
|
| - errno = EINVAL;
|
| - goto fail;
|
| - }
|
| - sem_init(&newsem, 1, value);
|
| - }
|
| - /* Create a temp file with the new semaphore contents
|
| - * and attempt to atomically link it as the new name */
|
| - clock_gettime(CLOCK_REALTIME, &ts);
|
| - snprintf(tmp, sizeof(tmp), "/dev/shm/tmp-%d", (int)ts.tv_nsec);
|
| - fd = open(tmp, O_CREAT|O_EXCL|FLAGS, mode);
|
| - if (fd < 0) {
|
| - if (errno == EEXIST) continue;
|
| - 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);
|
| - goto fail;
|
| - }
|
| - close(fd);
|
| - 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))
|
| - goto fail;
|
| - }
|
| + for (;;) {
|
| + /* If exclusive mode is not requested, try opening an
|
| + * existing file first and fall back to creation. */
|
| + if (flags != (O_CREAT | O_EXCL)) {
|
| + fd = open(name, FLAGS);
|
| + if (fd >= 0) {
|
| + if (fstat(fd, &st) < 0 ||
|
| + (map = mmap(0, sizeof(sem_t), PROT_READ | PROT_WRITE, MAP_SHARED,
|
| + fd, 0)) == MAP_FAILED) {
|
| + close(fd);
|
| + goto fail;
|
| + }
|
| + close(fd);
|
| + break;
|
| + }
|
| + if (errno != ENOENT)
|
| + goto fail;
|
| + }
|
| + if (!(flags & O_CREAT))
|
| + goto fail;
|
| + if (first) {
|
| + first = 0;
|
| + va_start(ap, flags);
|
| + mode = va_arg(ap, mode_t) & 0666;
|
| + value = va_arg(ap, unsigned);
|
| + va_end(ap);
|
| + if (value > SEM_VALUE_MAX) {
|
| + errno = EINVAL;
|
| + goto fail;
|
| + }
|
| + sem_init(&newsem, 1, value);
|
| + }
|
| + /* Create a temp file with the new semaphore contents
|
| + * and attempt to atomically link it as the new name */
|
| + clock_gettime(CLOCK_REALTIME, &ts);
|
| + snprintf(tmp, sizeof(tmp), "/dev/shm/tmp-%d", (int)ts.tv_nsec);
|
| + fd = open(tmp, O_CREAT | O_EXCL | FLAGS, mode);
|
| + if (fd < 0) {
|
| + if (errno == EEXIST)
|
| + continue;
|
| + 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);
|
| + goto fail;
|
| + }
|
| + close(fd);
|
| + 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))
|
| + goto fail;
|
| + }
|
|
|
| - /* See if the newly mapped semaphore is already mapped. If
|
| - * so, unmap the new mapping and use the existing one. Otherwise,
|
| - * add it to the table of mapped semaphores. */
|
| - LOCK(lock);
|
| - 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[slot].sem = 0;
|
| - slot = i;
|
| - map = semtab[i].sem;
|
| - }
|
| - semtab[slot].refcnt++;
|
| - semtab[slot].sem = map;
|
| - semtab[slot].ino = st.st_ino;
|
| - UNLOCK(lock);
|
| - pthread_setcancelstate(cs, 0);
|
| - return map;
|
| + /* See if the newly mapped semaphore is already mapped. If
|
| + * so, unmap the new mapping and use the existing one. Otherwise,
|
| + * add it to the table of mapped semaphores. */
|
| + LOCK(lock);
|
| + 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[slot].sem = 0;
|
| + slot = i;
|
| + map = semtab[i].sem;
|
| + }
|
| + 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;
|
| + pthread_setcancelstate(cs, 0);
|
| + LOCK(lock);
|
| + semtab[slot].sem = 0;
|
| + UNLOCK(lock);
|
| + return SEM_FAILED;
|
| }
|
|
|
| -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;
|
| - }
|
| - UNLOCK(lock);
|
| - munmap(sem, sizeof *sem);
|
| - return 0;
|
| +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;
|
| + }
|
| + UNLOCK(lock);
|
| + munmap(sem, sizeof *sem);
|
| + return 0;
|
| }
|
|
|