diff options
Diffstat (limited to 'sysdeps/pthread/sem_open.c')
-rw-r--r-- | sysdeps/pthread/sem_open.c | 116 |
1 files changed, 3 insertions, 113 deletions
diff --git a/sysdeps/pthread/sem_open.c b/sysdeps/pthread/sem_open.c index d666414f32..028d76a685 100644 --- a/sysdeps/pthread/sem_open.c +++ b/sysdeps/pthread/sem_open.c @@ -16,127 +16,17 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ -#include <errno.h> #include <fcntl.h> -#include <pthread.h> -#include <search.h> #include <semaphore.h> #include <stdarg.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> #include <unistd.h> #include <sys/mman.h> -#include <sys/stat.h> #include "semaphoreP.h" #include <shm-directory.h> +#include <sem_routines.h> #include <futex-internal.h> #include <libc-lock.h> -/* Comparison function for search of existing mapping. */ -int -attribute_hidden -__sem_search (const void *a, const void *b) -{ - const struct inuse_sem *as = (const struct inuse_sem *) a; - const struct inuse_sem *bs = (const struct inuse_sem *) b; - - if (as->ino != bs->ino) - /* Cannot return the difference the type is larger than int. */ - return as->ino < bs->ino ? -1 : (as->ino == bs->ino ? 0 : 1); - - if (as->dev != bs->dev) - /* Cannot return the difference the type is larger than int. */ - return as->dev < bs->dev ? -1 : (as->dev == bs->dev ? 0 : 1); - - return strcmp (as->name, bs->name); -} - - -/* The search tree for existing mappings. */ -void *__sem_mappings attribute_hidden; - -/* Lock to protect the search tree. */ -int __sem_mappings_lock attribute_hidden = LLL_LOCK_INITIALIZER; - - -/* Search for existing mapping and if possible add the one provided. */ -static sem_t * -check_add_mapping (const char *name, int fd, sem_t *existing) -{ - size_t namelen = strlen (name); - sem_t *result = SEM_FAILED; - - /* Get the information about the file. */ - struct stat64 st; - if (__fstat64 (fd, &st) == 0) - { - /* Get the lock. */ - lll_lock (__sem_mappings_lock, LLL_PRIVATE); - - /* Search for an existing mapping given the information we have. */ - struct inuse_sem *fake; - fake = (struct inuse_sem *) alloca (sizeof (*fake) + namelen); - memcpy (fake->name, name, namelen); - fake->dev = st.st_dev; - fake->ino = st.st_ino; - - struct inuse_sem **foundp = __tfind (fake, &__sem_mappings, - __sem_search); - if (foundp != NULL) - { - /* There is already a mapping. Use it. */ - result = (*foundp)->sem; - ++(*foundp)->refcnt; - } - else - { - /* We haven't found a mapping. Install ione. */ - struct inuse_sem *newp; - - newp = (struct inuse_sem *) malloc (sizeof (*newp) + namelen); - if (newp != NULL) - { - /* If the caller hasn't provided any map it now. */ - if (existing == SEM_FAILED) - existing = (sem_t *) mmap (NULL, sizeof (sem_t), - PROT_READ | PROT_WRITE, MAP_SHARED, - fd, 0); - - newp->dev = st.st_dev; - newp->ino = st.st_ino; - newp->refcnt = 1; - newp->sem = existing; - memcpy (newp->name, name, namelen); - - /* Insert the new value. */ - if (existing != MAP_FAILED - && __tsearch (newp, &__sem_mappings, __sem_search) != NULL) - /* Successful. */ - result = existing; - else - /* Something went wrong while inserting the new - value. We fail completely. */ - free (newp); - } - } - - /* Release the lock. */ - lll_unlock (__sem_mappings_lock, LLL_PRIVATE); - } - - if (result != existing && existing != SEM_FAILED && existing != MAP_FAILED) - { - /* Do not disturb errno. */ - int save = errno; - munmap (existing, sizeof (sem_t)); - errno = save; - } - - return result; -} - - sem_t * sem_open (const char *name, int oflag, ...) { @@ -183,7 +73,7 @@ sem_open (const char *name, int oflag, ...) else /* Check whether we already have this semaphore mapped and create one if necessary. */ - result = check_add_mapping (name, fd, SEM_FAILED); + result = __sem_check_add_mapping (name, fd, SEM_FAILED); } else { @@ -294,7 +184,7 @@ sem_open (const char *name, int oflag, ...) /* Insert the mapping into the search tree. This also determines whether another thread sneaked by and already added such a mapping despite the fact that we created it. */ - result = check_add_mapping (name, fd, result); + result = __sem_check_add_mapping (name, fd, result); } /* Now remove the temporary name. This should never fail. If |