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-rw-r--r--sysdeps/pthread/sem_close.c56
-rw-r--r--sysdeps/pthread/sem_open.c116
-rw-r--r--sysdeps/pthread/sem_routines.c187
-rw-r--r--sysdeps/pthread/sem_routines.h27
4 files changed, 221 insertions, 165 deletions
diff --git a/sysdeps/pthread/sem_close.c b/sysdeps/pthread/sem_close.c
index 8b6c9c6..6649196 100644
--- a/sysdeps/pthread/sem_close.c
+++ b/sysdeps/pthread/sem_close.c
@@ -17,65 +17,17 @@
<https://www.gnu.org/licenses/>. */
#include <errno.h>
-#include <search.h>
-#include <sys/mman.h>
#include "semaphoreP.h"
-
-struct walk_closure
-{
- sem_t *the_sem;
- struct inuse_sem *rec;
-};
-
-static void
-walker (const void *inodep, VISIT which, void *closure0)
-{
- struct walk_closure *closure = closure0;
- struct inuse_sem *nodep = *(struct inuse_sem **) inodep;
-
- if (nodep->sem == closure->the_sem)
- closure->rec = nodep;
-}
-
+#include <sem_routines.h>
int
sem_close (sem_t *sem)
{
- int result = 0;
-
- /* Get the lock. */
- lll_lock (__sem_mappings_lock, LLL_PRIVATE);
-
- /* Locate the entry for the mapping the caller provided. */
- struct inuse_sem *rec;
- {
- struct walk_closure closure = { .the_sem = sem, .rec = NULL };
- __twalk_r (__sem_mappings, walker, &closure);
- rec = closure.rec;
- }
- if (rec != NULL)
+ if (!__sem_remove_mapping (sem))
{
- /* Check the reference counter. If it is going to be zero, free
- all the resources. */
- if (--rec->refcnt == 0)
- {
- /* Remove the record from the tree. */
- (void) __tdelete (rec, &__sem_mappings, __sem_search);
-
- result = munmap (rec->sem, sizeof (sem_t));
-
- free (rec);
- }
- }
- else
- {
- /* This is no valid semaphore. */
- result = -1;
__set_errno (EINVAL);
+ return -1;
}
- /* Release the lock. */
- lll_unlock (__sem_mappings_lock, LLL_PRIVATE);
-
- return result;
+ return 0;
}
diff --git a/sysdeps/pthread/sem_open.c b/sysdeps/pthread/sem_open.c
index d666414..028d76a 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
diff --git a/sysdeps/pthread/sem_routines.c b/sysdeps/pthread/sem_routines.c
new file mode 100644
index 0000000..78d9364
--- /dev/null
+++ b/sysdeps/pthread/sem_routines.c
@@ -0,0 +1,187 @@
+/* Helper code for POSIX semaphore implementation.
+ Copyright (C) 2021 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <search.h>
+#include <semaphoreP.h>
+#include <sys/mman.h>
+#include <sem_routines.h>
+
+/* Keeping track of currently used mappings. */
+struct inuse_sem
+{
+ dev_t dev;
+ ino_t ino;
+ int refcnt;
+ sem_t *sem;
+ char name[];
+};
+
+/* Comparison function for search of existing mapping. */
+static int
+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. */
+static void *sem_mappings;
+
+/* Lock to protect the search tree. */
+static int sem_mappings_lock = LLL_LOCK_INITIALIZER;
+
+
+/* Search for existing mapping and if possible add the one provided. */
+sem_t *
+__sem_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;
+}
+
+struct walk_closure
+{
+ sem_t *the_sem;
+ struct inuse_sem *rec;
+};
+
+static void
+walker (const void *inodep, VISIT which, void *closure0)
+{
+ struct walk_closure *closure = closure0;
+ struct inuse_sem *nodep = *(struct inuse_sem **) inodep;
+
+ if (nodep->sem == closure->the_sem)
+ closure->rec = nodep;
+}
+
+bool
+__sem_remove_mapping (sem_t *sem)
+{
+ bool ret = true;
+
+ /* Get the lock. */
+ lll_lock (sem_mappings_lock, LLL_PRIVATE);
+
+ /* Locate the entry for the mapping the caller provided. */
+ struct inuse_sem *rec;
+ {
+ struct walk_closure closure = { .the_sem = sem, .rec = NULL };
+ __twalk_r (sem_mappings, walker, &closure);
+ rec = closure.rec;
+ }
+ if (rec != NULL)
+ {
+ /* Check the reference counter. If it is going to be zero, free
+ all the resources. */
+ if (--rec->refcnt == 0)
+ {
+ /* Remove the record from the tree. */
+ __tdelete (rec, &sem_mappings, sem_search);
+
+ if (munmap (rec->sem, sizeof (sem_t)) == -1)
+ ret = false;
+
+ free (rec);
+ }
+ }
+ else
+ ret = false;
+
+ /* Release the lock. */
+ lll_unlock (sem_mappings_lock, LLL_PRIVATE);
+
+ return ret;
+}
diff --git a/sysdeps/pthread/sem_routines.h b/sysdeps/pthread/sem_routines.h
new file mode 100644
index 0000000..25d3e88
--- /dev/null
+++ b/sysdeps/pthread/sem_routines.h
@@ -0,0 +1,27 @@
+/* Helper code for POSIX semaphore implementation.
+ Copyright (C) 2021 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#ifndef _SEM_ROUTINES_H
+#define _SEM_ROUTINES_H
+
+sem_t * __sem_check_add_mapping (const char *name, int fd, sem_t *existing)
+ attribute_hidden;
+
+bool __sem_remove_mapping (sem_t *sem) attribute_hidden;
+
+#endif
generated by cgit v1.1 at 2024-11-11 08:33:53 +0000