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Use umtx to implement process sharable semaphore, to make this work,

Browse source 
now type sema_t is a structure which can be put in a shared memory area,
and multiple processes can operate it concurrently.
User can either use mmap(MAP_SHARED) + sem_init(pshared=1) or use sem_open()
to initialize a shared semaphore.
Named semaphore uses file system and is located in /tmp directory, and its
file name is prefixed with 'SEMD', so now it is chroot or jail friendly.
In simplist cases, both for named and un-named semaphore, userland code
does not have to enter kernel to reduce/increase semaphore's count.
The semaphore is designed to be crash-safe, it means even if an application
is crashed in the middle of operating semaphore, the semaphore state is
still safely recovered by later use, there is no waiter counter maintained
by userland code.
The main semaphore code is in libc and libthr only has some necessary stubs,
this makes it possible that a non-threaded application can use semaphore
without linking to thread library.
Old semaphore implementation is kept libc to maintain binary compatibility.
The kernel ksem API is no longer used in the new implemenation.

Discussed on: threads@
This commit is contained in:
David Xu 2010-01-05 02:37:59 +00:00
parent 06b215fd3a
commit 9b0f1823b5
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=201546
18 changed files with 926 additions and 404 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
ObsoleteFiles.inc
View file

@ -14,6 +14,8 @@
# The file is partitioned: OLD_FILES first, then OLD_LIBS and OLD_DIRS last.
#
# 20100105: new userland semaphore implementation
OLD_FILES+=usr/include/sys/semaphore.h
# 20100103: ntptrace(8) removed
OLD_FILES+=usr/sbin/ntptrace
OLD_FILES+=usr/share/man/man8/ntptrace.8.gz

4
include/Makefile
View file

@ -18,7 +18,7 @@ INCS= a.out.h ar.h assert.h bitstring.h complex.h cpio.h _ctype.h ctype.h \
netdb.h nl_types.h nlist.h nss.h nsswitch.h paths.h \
printf.h proc_service.h pthread.h \
pthread_np.h pwd.h ranlib.h readpassphrase.h regex.h regexp.h \
res_update.h resolv.h runetype.h search.h setjmp.h \
res_update.h resolv.h runetype.h search.h semaphore.h setjmp.h \
signal.h spawn.h stab.h \
stdbool.h stddef.h stdio.h stdlib.h string.h stringlist.h \
strings.h sysexits.h tar.h termios.h tgmath.h \
@ -28,7 +28,7 @@ INCS= a.out.h ar.h assert.h bitstring.h complex.h cpio.h _ctype.h ctype.h \
MHDRS= float.h floatingpoint.h stdarg.h
PHDRS= sched.h semaphore.h _semaphore.h
PHDRS= sched.h _semaphore.h
LHDRS= aio.h errno.h fcntl.h linker_set.h poll.h stdint.h syslog.h \
ucontext.h

64
include/semaphore.h Normal file
View file

@ -0,0 +1,64 @@
/*
* Copyright (c) 2010 David Xu <davidxu@freebsd.org>
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 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.
*
* $FreeBSD$
*/
/* semaphore.h: POSIX 1003.1b semaphores */
#ifndef _SEMAPHORE_H_
#define _SEMAPHORE_H_
#include <sys/cdefs.h>
#include <sys/_types.h>
#include <sys/_umtx.h>
struct _sem {
__uint32_t _magic;
struct _usem _kern;
};
typedef struct _sem sem_t;
#define SEM_FAILED ((sem_t *)0)
#define SEM_VALUE_MAX __INT_MAX
struct timespec;
__BEGIN_DECLS
int sem_close(sem_t *);
int sem_destroy(sem_t *);
int sem_getvalue(sem_t * __restrict, int * __restrict);
int sem_init(sem_t *, int, unsigned int);
sem_t *sem_open(const char *, int, ...);
int sem_post(sem_t *);
int sem_timedwait(sem_t * __restrict, const struct timespec * __restrict);
int sem_trywait(sem_t *);
int sem_unlink(const char *);
int sem_wait(sem_t *);
__END_DECLS
#endif /* !_SEMAPHORE_H_ */

2
lib/libc/gen/Makefile.inc
View file

@ -25,7 +25,7 @@ SRCS+= __getosreldate.c __xuname.c \
pause.c pmadvise.c popen.c posix_spawn.c \
psignal.c pw_scan.c pwcache.c \
raise.c readdir.c readpassphrase.c rewinddir.c \
scandir.c seed48.c seekdir.c sem.c semctl.c \
scandir.c seed48.c seekdir.c sem.c sem_new.c semctl.c \
setdomainname.c sethostname.c setjmperr.c setmode.c \
setproctitle.c setprogname.c siginterrupt.c siglist.c signal.c \
sigsetops.c sleep.c srand48.c statvfs.c stringlist.c strtofflags.c \

51
lib/libc/gen/Symbol.map
View file

@ -236,16 +236,6 @@ FBSD_1.0 {
seekdir;
user_from_uid;
group_from_gid;
sem_init;
sem_destroy;
sem_open;
sem_close;
sem_unlink;
sem_wait;
sem_trywait;
sem_timedwait;
sem_post;
sem_getvalue;
setdomainname;
sethostname;
longjmperror;
@ -363,11 +353,23 @@ FBSD_1.1 {
semctl;
tcgetsid;
tcsetsid;
__pthread_cleanup_pop_imp;
__pthread_cleanup_push_imp;
};
FBSD_1.2 {
basename_r;
getpagesizes;
sem_close;
sem_destroy;
sem_getvalue;
sem_init;
sem_open;
sem_timedwait;
sem_trywait;
sem_post;
sem_wait;
sem_unlink;
};
FBSDprivate_1.0 {
@ -456,16 +458,6 @@ FBSDprivate_1.0 {
__pw_scan; /* Used by (at least) libutil */
__raise;
_raise;
__sem_init;
__sem_destroy;
__sem_open;
__sem_close;
__sem_unlink;
__sem_wait;
__sem_trywait;
__sem_timedwait;
__sem_post;
__sem_getvalue;
__sleep;
_sleep;
_rtld_allocate_tls;
@ -482,4 +474,23 @@ FBSDprivate_1.0 {
_wait;
__waitpid;
_waitpid;
_libc_sem_destroy;
_libc_sem_init;
_libc_sem_getvalue;
_libc_sem_trywait;
_libc_sem_wait;
_libc_sem_timedwait;
_libc_sem_post;
_libc_sem_init_compat;
_libc_sem_destroy_compat;
_libc_sem_open_compat;
_libc_sem_close_compat;
_libc_sem_unlink_compat;
_libc_sem_wait_compat;
_libc_sem_trywait_compat;
_libc_sem_timedwait_compat;
_libc_sem_post_compat;
_libc_sem_getvalue_compat;
};

4
lib/libc/gen/_pthread_stubs.c
View file

@ -119,6 +119,8 @@ pthread_func_entry_t __thr_jtable[PJT_MAX] = {
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_SETSPECIFIC */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_SIGMASK */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_TESTCANCEL */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_CLEANUP_POP_IMP */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_CLEANUP_PUSH_IMP */
};
/*
@ -265,6 +267,8 @@ STUB_FUNC2(pthread_kill, PJT_KILL, int, void *, int)
STUB_FUNC2(pthread_setcancelstate, PJT_SETCANCELSTATE, int, int, void *)
STUB_FUNC2(pthread_setcanceltype, PJT_SETCANCELTYPE, int, int, void *)
STUB_FUNC(pthread_testcancel, PJT_TESTCANCEL, void)
STUB_FUNC1(__pthread_cleanup_pop_imp, PJT_CLEANUP_POP_IMP, int, int)
STUB_FUNC2(__pthread_cleanup_push_imp, PJT_CLEANUP_PUSH_IMP, void, void*, void *);
static int
stub_zero(void)

238
lib/libc/gen/sem.c
View file

@ -1,4 +1,5 @@
/*
* Copyright (C) 2010 David Xu <davidxu@freebsd.org>.
* Copyright (C) 2000 Jason Evans <jasone@freebsd.org>.
* All rights reserved.
*
@ -59,34 +60,71 @@
#include "namespace.h"
#include <sys/types.h>
#include <sys/queue.h>
#include <machine/atomic.h>
#include <errno.h>
#include <sys/umtx.h>
#include <sys/_semaphore.h>
#include <limits.h>
#include <fcntl.h>
#include <pthread.h>
#include <semaphore.h>
#include <stdarg.h>
#include <stdlib.h>
#include <time.h>
#include <_semaphore.h>
#include "un-namespace.h"
#include "libc_private.h"
/*
* Old semaphore definitions.
*/
struct sem {
#define SEM_MAGIC ((u_int32_t) 0x09fa4012)
u_int32_t magic;
pthread_mutex_t lock;
pthread_cond_t gtzero;
u_int32_t count;
u_int32_t nwaiters;
#define SEM_USER (NULL)
semid_t semid; /* semaphore id if kernel (shared) semaphore */
int syssem; /* 1 if kernel (shared) semaphore */
LIST_ENTRY(sem) entry;
struct sem **backpointer;
};
typedef struct sem* sem_t;
#define SEM_FAILED ((sem_t *)0)
#define SEM_VALUE_MAX __INT_MAX
#define SYM_FB10(sym) __CONCAT(sym, _fb10)
#define SYM_FBP10(sym) __CONCAT(sym, _fbp10)
#define WEAK_REF(sym, alias) __weak_reference(sym, alias)
#define SYM_COMPAT(sym, impl, ver) __sym_compat(sym, impl, ver)
#define SYM_DEFAULT(sym, impl, ver) __sym_default(sym, impl, ver)
#define FB10_COMPAT(func, sym) \
WEAK_REF(func, SYM_FB10(sym)); \
SYM_COMPAT(sym, SYM_FB10(sym), FBSD_1.0)
#define FB10_COMPAT_PRIVATE(func, sym) \
WEAK_REF(func, SYM_FBP10(sym)); \
SYM_DEFAULT(sym, SYM_FBP10(sym), FBSDprivate_1.0)
static sem_t sem_alloc(unsigned int value, semid_t semid, int system_sem);
static void sem_free(sem_t sem);
static LIST_HEAD(, sem) named_sems = LIST_HEAD_INITIALIZER(named_sems);
static LIST_HEAD(, sem) named_sems = LIST_HEAD_INITIALIZER(&named_sems);
static pthread_mutex_t named_sems_mtx = PTHREAD_MUTEX_INITIALIZER;
__weak_reference(__sem_init, sem_init);
__weak_reference(__sem_destroy, sem_destroy);
__weak_reference(__sem_open, sem_open);
__weak_reference(__sem_close, sem_close);
__weak_reference(__sem_unlink, sem_unlink);
__weak_reference(__sem_wait, sem_wait);
__weak_reference(__sem_trywait, sem_trywait);
__weak_reference(__sem_timedwait, sem_timedwait);
__weak_reference(__sem_post, sem_post);
__weak_reference(__sem_getvalue, sem_getvalue);
FB10_COMPAT(_libc_sem_init_compat, sem_init);
FB10_COMPAT(_libc_sem_destroy_compat, sem_destroy);
FB10_COMPAT(_libc_sem_open_compat, sem_open);
FB10_COMPAT(_libc_sem_close_compat, sem_close);
FB10_COMPAT(_libc_sem_unlink_compat, sem_unlink);
FB10_COMPAT(_libc_sem_wait_compat, sem_wait);
FB10_COMPAT(_libc_sem_trywait_compat, sem_trywait);
FB10_COMPAT(_libc_sem_timedwait_compat, sem_timedwait);
FB10_COMPAT(_libc_sem_post_compat, sem_post);
FB10_COMPAT(_libc_sem_getvalue_compat, sem_getvalue);
static inline int
sem_check_validity(sem_t *sem)
@ -104,8 +142,6 @@ static void
sem_free(sem_t sem)
{
_pthread_mutex_destroy(&sem->lock);
_pthread_cond_destroy(&sem->gtzero);
sem->magic = 0;
free(sem);
}
@ -131,13 +167,11 @@ sem_alloc(unsigned int value, semid_t semid, int system_sem)
sem->magic = SEM_MAGIC;
sem->semid = semid;
sem->syssem = system_sem;
sem->lock = PTHREAD_MUTEX_INITIALIZER;
sem->gtzero = PTHREAD_COND_INITIALIZER;
return (sem);
}
int
__sem_init(sem_t *sem, int pshared, unsigned int value)
_libc_sem_init_compat(sem_t *sem, int pshared, unsigned int value)
{
semid_t semid;
@ -147,26 +181,27 @@ __sem_init(sem_t *sem, int pshared, unsigned int value)
* pthread_cond_wait() is just a stub that doesn't really
* wait.
*/
if (ksem_init(&semid, value) != 0)
semid = (semid_t)SEM_USER;
if ((pshared != 0) && ksem_init(&semid, value) != 0)
return (-1);
(*sem) = sem_alloc(value, semid, 1);
*sem = sem_alloc(value, semid, pshared);
if ((*sem) == NULL) {
ksem_destroy(semid);
if (pshared != 0)
ksem_destroy(semid);
return (-1);
}
return (0);
}
int
__sem_destroy(sem_t *sem)
_libc_sem_destroy_compat(sem_t *sem)
{
int retval;
if (sem_check_validity(sem) != 0)
return (-1);
_pthread_mutex_lock(&(*sem)->lock);
/*
* If this is a system semaphore let the kernel track it otherwise
* make sure there are no waiters.
@ -181,18 +216,14 @@ __sem_destroy(sem_t *sem)
retval = 0;
(*sem)->magic = 0;
}
_pthread_mutex_unlock(&(*sem)->lock);
if (retval == 0) {
_pthread_mutex_destroy(&(*sem)->lock);
_pthread_cond_destroy(&(*sem)->gtzero);
if (retval == 0)
sem_free(*sem);
}
return (retval);
}
sem_t *
__sem_open(const char *name, int oflag, ...)
_libc_sem_open_compat(const char *name, int oflag, ...)
{
sem_t *sem;
sem_t s;
@ -255,7 +286,7 @@ __sem_open(const char *name, int oflag, ...)
}
int
__sem_close(sem_t *sem)
_libc_sem_close_compat(sem_t *sem)
{
if (sem_check_validity(sem) != 0)
@ -280,68 +311,156 @@ __sem_close(sem_t *sem)
}
int
__sem_unlink(const char *name)
_libc_sem_unlink_compat(const char *name)
{
return (ksem_unlink(name));
}
int
__sem_wait(sem_t *sem)
static int
enable_async_cancel(void)
{
int old;
if (sem_check_validity(sem) != 0)
_pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &old);
return (old);
}
static void
restore_async_cancel(int val)
{
_pthread_setcanceltype(val, NULL);
}
static int
_umtx_wait_uint(volatile unsigned *mtx, unsigned id, const struct timespec *timeout)
{
if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
timeout->tv_nsec <= 0))) {
errno = ETIMEDOUT;
return (-1);
}
return _umtx_op(__DEVOLATILE(void *, mtx),
UMTX_OP_WAIT_UINT_PRIVATE, id, NULL, __DECONST(void*, timeout));
}
return (ksem_wait((*sem)->semid));
static int
_umtx_wake(volatile void *mtx)
{
return _umtx_op(__DEVOLATILE(void *, mtx), UMTX_OP_WAKE_PRIVATE,
1, NULL, NULL);
}
#define TIMESPEC_SUB(dst, src, val) \
do { \
(dst)->tv_sec = (src)->tv_sec - (val)->tv_sec; \
(dst)->tv_nsec = (src)->tv_nsec - (val)->tv_nsec; \
if ((dst)->tv_nsec < 0) { \
(dst)->tv_sec--; \
(dst)->tv_nsec += 1000000000; \
} \
} while (0)
static void
sem_cancel_handler(void *arg)
{
sem_t *sem = arg;
atomic_add_int(&(*sem)->nwaiters, -1);
if ((*sem)->nwaiters && (*sem)->count)
_umtx_wake(&(*sem)->count);
}
int
__sem_trywait(sem_t *sem)
_libc_sem_timedwait_compat(sem_t * __restrict sem,
const struct timespec * __restrict abstime)
{
int retval;
struct timespec ts, ts2;
int val, retval, saved_cancel;
if (sem_check_validity(sem) != 0)
return (-1);
if ((*sem)->syssem != 0)
retval = ksem_trywait((*sem)->semid);
else {
_pthread_mutex_lock(&(*sem)->lock);
if ((*sem)->count > 0) {
(*sem)->count--;
retval = 0;
} else {
errno = EAGAIN;
retval = -1;
if ((*sem)->syssem != 0) {
saved_cancel = enable_async_cancel();
retval = ksem_wait((*sem)->semid);
restore_async_cancel(saved_cancel);
return (retval);
}
retval = 0;
_pthread_testcancel();
for (;;) {
while ((val = (*sem)->count) > 0) {
if (atomic_cmpset_acq_int(&(*sem)->count, val, val - 1))
return (0);
}
_pthread_mutex_unlock(&(*sem)->lock);
if (retval)
break;
if (abstime) {
if (abstime->tv_nsec >= 1000000000 || abstime->tv_nsec < 0) {
errno = EINVAL;
return (-1);
}
clock_gettime(CLOCK_REALTIME, &ts);
TIMESPEC_SUB(&ts2, abstime, &ts);
}
atomic_add_int(&(*sem)->nwaiters, 1);
pthread_cleanup_push(sem_cancel_handler, sem);
saved_cancel = enable_async_cancel();
retval = _umtx_wait_uint(&(*sem)->count, 0, abstime ? &ts2 : NULL);
restore_async_cancel(saved_cancel);
pthread_cleanup_pop(0);
atomic_add_int(&(*sem)->nwaiters, -1);
}
return (retval);
}
int
__sem_timedwait(sem_t * __restrict sem,
const struct timespec * __restrict abs_timeout)
_libc_sem_wait_compat(sem_t *sem)
{
if (sem_check_validity(sem) != 0)
return (-1);
return (ksem_timedwait((*sem)->semid, abs_timeout));
return _libc_sem_timedwait_compat(sem, NULL);
}
int
__sem_post(sem_t *sem)
_libc_sem_trywait_compat(sem_t *sem)
{
int val;
if (sem_check_validity(sem) != 0)
return (-1);
if ((*sem)->syssem != 0)
return ksem_trywait((*sem)->semid);
while ((val = (*sem)->count) > 0) {
if (atomic_cmpset_acq_int(&(*sem)->count, val, val - 1))
return (0);
}
errno = EAGAIN;
return (-1);
}
int
_libc_sem_post_compat(sem_t *sem)
{
if (sem_check_validity(sem) != 0)
return (-1);
return (ksem_post((*sem)->semid));
if ((*sem)->syssem != 0)
return ksem_post((*sem)->semid);
atomic_add_rel_int(&(*sem)->count, 1);
if ((*sem)->nwaiters)
return _umtx_wake(&(*sem)->count);
return (0);
}
int
__sem_getvalue(sem_t * __restrict sem, int * __restrict sval)
_libc_sem_getvalue_compat(sem_t * __restrict sem, int * __restrict sval)
{
int retval;
@ -351,10 +470,7 @@ __sem_getvalue(sem_t * __restrict sem, int * __restrict sval)
if ((*sem)->syssem != 0)
retval = ksem_getvalue((*sem)->semid, sval);
else {
_pthread_mutex_lock(&(*sem)->lock);
*sval = (int)(*sem)->count;
_pthread_mutex_unlock(&(*sem)->lock);
retval = 0;
}
return (retval);

470
lib/libc/gen/sem_new.c Normal file
View file

@ -0,0 +1,470 @@
/*
* Copyright (C) 2010 David Xu <davidxu@freebsd.org>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice(s), this list of conditions and the following disclaimer as
* the first lines of this file unmodified other than the possible
* addition of one or more copyright notices.
* 2. Redistributions in binary form must reproduce the above copyright
* notice(s), this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT 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.
*
* $FreeBSD$
*/
#include "namespace.h"
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <errno.h>
#include <machine/atomic.h>
#include <sys/umtx.h>
#include <limits.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <semaphore.h>
#include <unistd.h>
#include "un-namespace.h"
__weak_reference(_libc_sem_close, sem_close);
__weak_reference(_libc_sem_close, _sem_close);
__weak_reference(_libc_sem_destroy, sem_destroy);
__weak_reference(_libc_sem_destroy, _sem_destroy);
__weak_reference(_libc_sem_getvalue, sem_getvalue);
__weak_reference(_libc_sem_getvalue, _sem_getvalue);
__weak_reference(_libc_sem_init, sem_init);
__weak_reference(_libc_sem_init, _sem_init);
__weak_reference(_libc_sem_open, sem_open);
__weak_reference(_libc_sem_open, _sem_open);
__weak_reference(_libc_sem_post, sem_post);
__weak_reference(_libc_sem_post, _sem_post);
__weak_reference(_libc_sem_timedwait, sem_timedwait);
__weak_reference(_libc_sem_timedwait, _sem_timedwait);
__weak_reference(_libc_sem_trywait, sem_trywait);
__weak_reference(_libc_sem_trywait, _sem_trywait);
__weak_reference(_libc_sem_unlink, sem_unlink);
__weak_reference(_libc_sem_unlink, _sem_unlink);
__weak_reference(_libc_sem_wait, sem_wait);
__weak_reference(_libc_sem_wait, _sem_wait);
#define SEM_PREFIX "/tmp/SEMD"
#define SEM_MAGIC ((u_int32_t)0x73656d31)
struct sem_nameinfo {
int open_count;
char *name;
sem_t *sem;
LIST_ENTRY(sem_nameinfo) next;
};
static pthread_once_t once = PTHREAD_ONCE_INIT;
static pthread_mutex_t sem_llock;
static LIST_HEAD(,sem_nameinfo) sem_list = LIST_HEAD_INITIALIZER(sem_list);
static void
sem_prefork()
{
_pthread_mutex_lock(&sem_llock);
}
static void
sem_postfork()
{
_pthread_mutex_unlock(&sem_llock);
}
static void
sem_child_postfork()
{
_pthread_mutex_unlock(&sem_llock);
}
static void
sem_module_init(void)
{
pthread_mutexattr_t ma;
_pthread_mutexattr_init(&ma);
_pthread_mutexattr_settype(&ma, PTHREAD_MUTEX_RECURSIVE);
_pthread_mutex_init(&sem_llock, &ma);
_pthread_mutexattr_destroy(&ma);
_pthread_atfork(sem_prefork, sem_postfork, sem_child_postfork);
}
static inline int
sem_check_validity(sem_t *sem)
{
if (sem->_magic == SEM_MAGIC)
return (0);
else {
errno = EINVAL;
return (-1);
}
}
int
_libc_sem_init(sem_t *sem, int pshared, unsigned int value)
{
if (value > SEM_VALUE_MAX) {
errno = EINVAL;
return (-1);
}
bzero(sem, sizeof(sem_t));
sem->_magic = SEM_MAGIC;
sem->_kern._count = (u_int32_t)value;
sem->_kern._has_waiters = 0;
sem->_kern._flags = pshared ? USYNC_PROCESS_SHARED : 0;
return (0);
}
sem_t *
_libc_sem_open(const char *name, int flags, ...)
{
char path[PATH_MAX];
struct stat sb;
va_list ap;
struct sem_nameinfo *ni = NULL;
sem_t *sem = NULL;
int fd = -1, mode, len;
if (name[0] != '/') {
errno = EINVAL;
return (NULL);
}
name++;
if (flags & ~(O_CREAT|O_EXCL)) {
errno = EINVAL;
return (NULL);
}
_pthread_once(&once, sem_module_init);
_pthread_mutex_lock(&sem_llock);
LIST_FOREACH(ni, &sem_list, next) {
if (strcmp(name, ni->name) == 0) {
ni->open_count++;
sem = ni->sem;
_pthread_mutex_unlock(&sem_llock);
return (sem);
}
}
if (flags & O_CREAT) {
va_start(ap, flags);
mode = va_arg(ap, int);
va_end(ap);
}
len = sizeof(*ni) + strlen(name) + 1;
ni = (struct sem_nameinfo *)malloc(len);
if (ni == NULL) {
errno = ENOSPC;
goto error;
}
ni->name = (char *)(ni+1);
strcpy(ni->name, name);
strcpy(path, SEM_PREFIX);
if (strlcat(path, name, sizeof(path)) >= sizeof(path)) {
errno = ENAMETOOLONG;
goto error;
}
fd = _open(path, flags|O_RDWR, mode);
if (fd == -1)
goto error;
if (flock(fd, LOCK_EX) == -1)
goto error;
if (_fstat(fd, &sb)) {
flock(fd, LOCK_UN);
goto error;
}
if (sb.st_size < sizeof(sem_t)) {
sem_t tmp;
tmp._magic = SEM_MAGIC;
tmp._kern._has_waiters = 0;
tmp._kern._count = 0;
tmp._kern._flags = USYNC_PROCESS_SHARED | SEM_NAMED;
if (_write(fd, &tmp, sizeof(tmp)) != sizeof(tmp)) {
flock(fd, LOCK_UN);
goto error;
}
}
flock(fd, LOCK_UN);
sem = (sem_t *)mmap(NULL, sizeof(sem_t), PROT_READ|PROT_WRITE,
MAP_SHARED|MAP_NOSYNC, fd, 0);
if (sem == MAP_FAILED) {
sem = NULL;
if (errno == ENOMEM)
errno = ENOSPC;
goto error;
}
if (sem->_magic != SEM_MAGIC) {
errno = EINVAL;
goto error;
}
ni->open_count = 1;
ni->sem = sem;
LIST_INSERT_HEAD(&sem_list, ni, next);
_pthread_mutex_unlock(&sem_llock);
_close(fd);
return (sem);
error:
_pthread_mutex_unlock(&sem_llock);
if (fd != -1)
_close(fd);
if (sem != NULL)
munmap(sem, sizeof(sem_t));
free(ni);
return (SEM_FAILED);
}
int
_libc_sem_close(sem_t *sem)
{
struct sem_nameinfo *ni;
if (sem_check_validity(sem) != 0)
return (-1);
if (!(sem->_kern._flags & SEM_NAMED)) {
errno = EINVAL;
return (-1);
}
_pthread_mutex_lock(&sem_llock);
LIST_FOREACH(ni, &sem_list, next) {
if (sem == ni->sem) {
if (--ni->open_count > 0) {
_pthread_mutex_unlock(&sem_llock);
return (0);
}
else
break;
}
}
if (ni) {
LIST_REMOVE(ni, next);
_pthread_mutex_unlock(&sem_llock);
munmap(sem, sizeof(*sem));
free(ni);
return (0);
}
_pthread_mutex_unlock(&sem_llock);
return (-1);
}
int
_libc_sem_unlink(const char *name)
{
char path[PATH_MAX];
if (name[0] != '/') {
errno = ENOENT;
return -1;
}
name++;
strcpy(path, SEM_PREFIX);
if (strlcat(path, name, sizeof(path)) >= sizeof(path)) {
errno = ENAMETOOLONG;
return (-1);
}
return unlink(path);
}
int
_libc_sem_destroy(sem_t *sem)
{
if (sem_check_validity(sem) != 0)
return (-1);
if (sem->_kern._flags & SEM_NAMED) {
errno = EINVAL;
return (-1);
}
sem->_magic = 0;
return (0);
}
int
_libc_sem_getvalue(sem_t * __restrict sem, int * __restrict sval)
{
if (sem_check_validity(sem) != 0)
return (-1);
*sval = (int)sem->_kern._count;
return (0);
}
static int
usem_wake(struct _usem *sem)
{
if (!sem->_has_waiters)
return (0);
return _umtx_op(sem, UMTX_OP_SEM_WAKE, 0, NULL, NULL);
}
static int
usem_wait(struct _usem *sem, const struct timespec *timeout)
{
if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
timeout->tv_nsec <= 0))) {
errno = ETIMEDOUT;
return (-1);
}
return _umtx_op(sem, UMTX_OP_SEM_WAIT, 0, NULL,
__DECONST(void*, timeout));
}
int
_libc_sem_trywait(sem_t *sem)
{
int val;
if (sem_check_validity(sem) != 0)
return (-1);
while ((val = sem->_kern._count) > 0) {
if (atomic_cmpset_acq_int(&sem->_kern._count, val, val - 1))
return (0);
}
errno = EAGAIN;
return (-1);
}
static void
sem_cancel_handler(void *arg)
{
sem_t *sem = arg;
if (sem->_kern._has_waiters && sem->_kern._count)
usem_wake(&sem->_kern);
}
#define TIMESPEC_SUB(dst, src, val) \
do { \
(dst)->tv_sec = (src)->tv_sec - (val)->tv_sec; \
(dst)->tv_nsec = (src)->tv_nsec - (val)->tv_nsec; \
if ((dst)->tv_nsec < 0) { \
(dst)->tv_sec--; \
(dst)->tv_nsec += 1000000000; \
} \
} while (0)
static int
enable_async_cancel(void)
{
int old;
_pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &old);
return (old);
}
static void
restore_async_cancel(int val)
{
_pthread_setcanceltype(val, NULL);
}
int
_libc_sem_timedwait(sem_t * __restrict sem,
const struct timespec * __restrict abstime)
{
struct timespec ts, ts2;
int val, retval, saved_cancel;
if (sem_check_validity(sem) != 0)
return (-1);
retval = 0;
_pthread_testcancel();
for (;;) {
while ((val = sem->_kern._count) > 0) {
if (atomic_cmpset_acq_int(&sem->_kern._count, val, val - 1))
return (0);
}
if (retval)
break;
/*
* The timeout argument is only supposed to
* be checked if the thread would have blocked.
*/
if (abstime != NULL) {
if (abstime->tv_nsec >= 1000000000 || abstime->tv_nsec < 0) {
errno = EINVAL;
return (-1);
}
clock_gettime(CLOCK_REALTIME, &ts);
TIMESPEC_SUB(&ts2, abstime, &ts);
}
pthread_cleanup_push(sem_cancel_handler, sem);
saved_cancel = enable_async_cancel();
retval = usem_wait(&sem->_kern, abstime ? &ts2 : NULL);
restore_async_cancel(saved_cancel);
pthread_cleanup_pop(0);
}
return (retval);
}
int
_libc_sem_wait(sem_t *sem)
{
return _libc_sem_timedwait(sem, NULL);
}
/*
* POSIX:
* The sem_post() interface is reentrant with respect to signals and may be
* invoked from a signal-catching function.
* The implementation does not use lock, so it should be safe.
*/
int
_libc_sem_post(sem_t *sem)
{
if (sem_check_validity(sem) != 0)
return (-1);
atomic_add_rel_int(&sem->_kern._count, 1);
if (sem->_kern._has_waiters)
return usem_wake(&sem->_kern);
return (0);
}

2
lib/libc/include/libc_private.h
View file

@ -127,6 +127,8 @@ typedef enum {
PJT_SETSPECIFIC,
PJT_SIGMASK,
PJT_TESTCANCEL,
PJT_CLEANUP_POP_IMP,
PJT_CLEANUP_PUSH_IMP,
PJT_MAX
} pjt_index_t;

21
lib/libthr/pthread.map
View file

@ -145,13 +145,6 @@ FBSD_1.0 {
recvfrom;
recvmsg;
select;
sem_destroy;
sem_getvalue;
sem_init;
sem_post;
sem_timedwait;
sem_trywait;
sem_wait;
sendmsg;
sendto;
sigaction;
@ -348,13 +341,6 @@ FBSDprivate_1.0 {
_pthread_timedjoin_np;
_pthread_yield;
_raise;
_sem_destroy;
_sem_getvalue;
_sem_init;
_sem_post;
_sem_timedwait;
_sem_trywait;
_sem_wait;
_sigaction;
_sigprocmask;
_sigsuspend;
@ -410,4 +396,11 @@ FBSD_1.1 {
FBSD_1.2 {
openat;
sem_destroy;
sem_getvalue;
sem_init;
sem_post;
sem_timedwait;
sem_trywait;
sem_wait;
};

1
lib/libthr/thread/Makefile.inc
View file

@ -41,6 +41,7 @@ SRCS+= \
thr_rwlockattr.c \
thr_self.c \
thr_sem.c \
thr_sem_new.c \
thr_setprio.c \
thr_setschedparam.c \
thr_sig.c \

4
lib/libthr/thread/thr_init.c
View file

@ -246,7 +246,9 @@ static pthread_func_t jmp_table[][2] = {
{DUAL_ENTRY(_pthread_setcanceltype)}, /* PJT_SETCANCELTYPE */
{DUAL_ENTRY(_pthread_setspecific)}, /* PJT_SETSPECIFIC */
{DUAL_ENTRY(_pthread_sigmask)}, /* PJT_SIGMASK */
{DUAL_ENTRY(_pthread_testcancel)} /* PJT_TESTCANCEL */
{DUAL_ENTRY(_pthread_testcancel)}, /* PJT_TESTCANCEL */
{DUAL_ENTRY(__pthread_cleanup_pop_imp)},/* PJT_CLEANUP_POP_IMP */
{DUAL_ENTRY(__pthread_cleanup_push_imp)}/* PJT_CLEANUP_PUSH_IMP */
};
static int init_once = 0;

17
lib/libthr/thread/thr_private.h
View file

@ -52,6 +52,20 @@
#include <sys/thr.h>
#include <pthread.h>
#define SYM_FB10(sym) __CONCAT(sym, _fb10)
#define SYM_FBP10(sym) __CONCAT(sym, _fbp10)
#define WEAK_REF(sym, alias) __weak_reference(sym, alias)
#define SYM_COMPAT(sym, impl, ver) __sym_compat(sym, impl, ver)
#define SYM_DEFAULT(sym, impl, ver) __sym_default(sym, impl, ver)
#define FB10_COMPAT(func, sym) \
WEAK_REF(func, SYM_FB10(sym)); \
SYM_COMPAT(sym, SYM_FB10(sym), FBSD_1.0)
#define FB10_COMPAT_PRIVATE(func, sym) \
WEAK_REF(func, SYM_FBP10(sym)); \
SYM_DEFAULT(sym, SYM_FBP10(sym), FBSDprivate_1.0)
#ifndef __hidden
#define __hidden __attribute__((visibility("hidden")))
#endif
@ -660,6 +674,9 @@ int _schedparam_to_rtp(int policy, const struct sched_param *param,
void _thread_bp_create(void);
void _thread_bp_death(void);
int _sched_yield(void);
void _thr_sem_prefork(void);
void _thr_sem_postfork(void);
void _thr_sem_child_postfork(void);
void _pthread_cleanup_push(void (*)(void *), void *);
void _pthread_cleanup_pop(int);

256
lib/libthr/thread/thr_sem.c
View file

@ -36,7 +36,6 @@
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <semaphore.h>
#include <stdlib.h>
#include <time.h>
#include <_semaphore.h>
@ -44,248 +43,73 @@
#include "thr_private.h"
FB10_COMPAT(_sem_init_compat, sem_init);
FB10_COMPAT(_sem_destroy_compat, sem_destroy);
FB10_COMPAT(_sem_getvalue_compat, sem_getvalue);
FB10_COMPAT(_sem_trywait_compat, sem_trywait);
FB10_COMPAT(_sem_wait_compat, sem_wait);
FB10_COMPAT(_sem_timedwait_compat, sem_timedwait);
FB10_COMPAT(_sem_post_compat, sem_post);
__weak_reference(_sem_init, sem_init);
__weak_reference(_sem_destroy, sem_destroy);
__weak_reference(_sem_getvalue, sem_getvalue);
__weak_reference(_sem_trywait, sem_trywait);
__weak_reference(_sem_wait, sem_wait);
__weak_reference(_sem_timedwait, sem_timedwait);
__weak_reference(_sem_post, sem_post);
typedef struct sem *sem_t;
extern int _libc_sem_init_compat(sem_t *sem, int pshared, unsigned int value);
extern int _libc_sem_destroy_compat(sem_t *sem);
extern int _libc_sem_getvalue_compat(sem_t * __restrict sem, int * __restrict sval);
extern int _libc_sem_trywait_compat(sem_t *sem);
extern int _libc_sem_wait_compat(sem_t *sem);
extern int _libc_sem_timedwait_compat(sem_t * __restrict sem,
const struct timespec * __restrict abstime);
extern int _libc_sem_post_compat(sem_t *sem);
static inline int
sem_check_validity(sem_t *sem)
int _sem_init_compat(sem_t *sem, int pshared, unsigned int value);
int _sem_destroy_compat(sem_t *sem);
int _sem_getvalue_compat(sem_t * __restrict sem, int * __restrict sval);
int _sem_trywait_compat(sem_t *sem);
int _sem_wait_compat(sem_t *sem);
int _sem_timedwait_compat(sem_t * __restrict sem,
const struct timespec * __restrict abstime);
int _sem_post_compat(sem_t *sem);
int
_sem_init_compat(sem_t *sem, int pshared, unsigned int value)
{
if ((sem != NULL) && ((*sem)->magic == SEM_MAGIC))
return (0);
else {
errno = EINVAL;
return (-1);
}
}
static sem_t
sem_alloc(unsigned int value, semid_t semid, int system_sem)
{
sem_t sem;
if (value > SEM_VALUE_MAX) {
errno = EINVAL;
return (NULL);
}
sem = (sem_t)malloc(sizeof(struct sem));
if (sem == NULL) {
errno = ENOSPC;
return (NULL);
}
bzero(sem, sizeof(*sem));
/*
* Fortunatly count and nwaiters are adjacency, so we can
* use umtx_wait to wait on it, umtx_wait needs an address
* can be accessed as a long interger.
*/
sem->count = (u_int32_t)value;
sem->nwaiters = 0;
sem->magic = SEM_MAGIC;
sem->semid = semid;
sem->syssem = system_sem;
return (sem);
return _libc_sem_init_compat(sem, pshared, value);
}
int
_sem_init(sem_t *sem, int pshared, unsigned int value)
_sem_destroy_compat(sem_t *sem)
{
semid_t semid;
semid = (semid_t)SEM_USER;
if ((pshared != 0) && (ksem_init(&semid, value) != 0))
return (-1);
(*sem) = sem_alloc(value, semid, pshared);
if ((*sem) == NULL) {
if (pshared != 0)
ksem_destroy(semid);
return (-1);
}
return (0);
return _libc_sem_destroy_compat(sem);
}
int
_sem_destroy(sem_t *sem)
_sem_getvalue_compat(sem_t * __restrict sem, int * __restrict sval)
{
int retval;
if (sem_check_validity(sem) != 0)
return (-1);
/*
* If this is a system semaphore let the kernel track it otherwise
* make sure there are no waiters.
*/
if ((*sem)->syssem != 0)
retval = ksem_destroy((*sem)->semid);
else {
retval = 0;
(*sem)->magic = 0;
}
if (retval == 0)
free(*sem);
return (retval);
return _libc_sem_getvalue_compat(sem, sval);
}
int
_sem_getvalue(sem_t * __restrict sem, int * __restrict sval)
_sem_trywait_compat(sem_t *sem)
{
int retval;
if (sem_check_validity(sem) != 0)
return (-1);
if ((*sem)->syssem != 0)
retval = ksem_getvalue((*sem)->semid, sval);
else {
*sval = (int)(*sem)->count;
retval = 0;
}
return (retval);
return _libc_sem_trywait_compat(sem);
}
int
_sem_trywait(sem_t *sem)
_sem_wait_compat(sem_t *sem)
{
int val;
if (sem_check_validity(sem) != 0)
return (-1);
if ((*sem)->syssem != 0)
return (ksem_trywait((*sem)->semid));
while ((val = (*sem)->count) > 0) {
if (atomic_cmpset_acq_int(&(*sem)->count, val, val - 1))
return (0);
}
errno = EAGAIN;
return (-1);
}
static void
sem_cancel_handler(void *arg)
{
sem_t *sem = arg;
atomic_add_int(&(*sem)->nwaiters, -1);
if ((*sem)->nwaiters && (*sem)->count)
_thr_umtx_wake(&(*sem)->count, 1, 0);
return _libc_sem_wait_compat(sem);
}
int
_sem_wait(sem_t *sem)
{
struct pthread *curthread;
int val, retval;
if (sem_check_validity(sem) != 0)
return (-1);
curthread = _get_curthread();
if ((*sem)->syssem != 0) {
_thr_cancel_enter(curthread);
retval = ksem_wait((*sem)->semid);
_thr_cancel_leave(curthread);
return (retval);
}
_pthread_testcancel();
do {
while ((val = (*sem)->count) > 0) {
if (atomic_cmpset_acq_int(&(*sem)->count, val, val - 1))
return (0);
}
atomic_add_int(&(*sem)->nwaiters, 1);
THR_CLEANUP_PUSH(curthread, sem_cancel_handler, sem);
_thr_cancel_enter(curthread);
retval = _thr_umtx_wait_uint(&(*sem)->count, 0, NULL, 0);
_thr_cancel_leave(curthread);
THR_CLEANUP_POP(curthread, 0);
atomic_add_int(&(*sem)->nwaiters, -1);
} while (retval == 0);
errno = retval;
return (-1);
}
int
_sem_timedwait(sem_t * __restrict sem,
_sem_timedwait_compat(sem_t * __restrict sem,
const struct timespec * __restrict abstime)
{
struct timespec ts, ts2;
struct pthread *curthread;
int val, retval;
if (sem_check_validity(sem) != 0)
return (-1);
curthread = _get_curthread();
if ((*sem)->syssem != 0) {
_thr_cancel_enter(curthread);
retval = ksem_timedwait((*sem)->semid, abstime);
_thr_cancel_leave(curthread);
return (retval);
}
/*
* The timeout argument is only supposed to
* be checked if the thread would have blocked.
*/
_pthread_testcancel();
do {
while ((val = (*sem)->count) > 0) {
if (atomic_cmpset_acq_int(&(*sem)->count, val, val - 1))
return (0);
}
if (abstime == NULL) {
errno = EINVAL;
return (-1);
}
clock_gettime(CLOCK_REALTIME, &ts);
TIMESPEC_SUB(&ts2, abstime, &ts);
atomic_add_int(&(*sem)->nwaiters, 1);
THR_CLEANUP_PUSH(curthread, sem_cancel_handler, sem);
_thr_cancel_enter(curthread);
retval = _thr_umtx_wait_uint((uint32_t*)&(*sem)->count, 0, &ts2, 0);
_thr_cancel_leave(curthread);
THR_CLEANUP_POP(curthread, 0);
atomic_add_int(&(*sem)->nwaiters, -1);
} while (retval == 0);
errno = retval;
return (-1);
return _libc_sem_timedwait_compat(sem, abstime);
}
/*
* sem_post() is required to be safe to call from within
* signal handlers, these code should work as that.
*/
int
_sem_post(sem_t *sem)
_sem_post_compat(sem_t *sem)
{
int retval = 0;
if (sem_check_validity(sem) != 0)
return (-1);
if ((*sem)->syssem != 0)
return (ksem_post((*sem)->semid));
atomic_add_rel_int(&(*sem)->count, 1);
if ((*sem)->nwaiters) {
retval = _thr_umtx_wake(&(*sem)->count, 1, 0);
if (retval != 0)
retval = -1;
}
return (retval);
return _libc_sem_post_compat(sem);
}

103
lib/libthr/thread/thr_sem_new.c Normal file
View file

@ -0,0 +1,103 @@
/*
* Copyright (C) 2010 David Xu <davidxu@freebsd.org>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice(s), this list of conditions and the following disclaimer as
* the first lines of this file unmodified other than the possible
* addition of one or more copyright notices.
* 2. Redistributions in binary form must reproduce the above copyright
* notice(s), this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT 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.
*
* $FreeBSD$
*/
#include "namespace.h"
#include <sys/types.h>
#include <sys/queue.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdlib.h>
#include <time.h>
#include <semaphore.h>
#include "un-namespace.h"
#include "thr_private.h"
__weak_reference(_sem_init, sem_init);
__weak_reference(_sem_destroy, sem_destroy);
__weak_reference(_sem_getvalue, sem_getvalue);
__weak_reference(_sem_trywait, sem_trywait);
__weak_reference(_sem_wait, sem_wait);
__weak_reference(_sem_timedwait, sem_timedwait);
__weak_reference(_sem_post, sem_post);
extern int _libc_sem_init(sem_t *sem, int pshared, unsigned int value);
extern int _libc_sem_destroy(sem_t *sem);
extern int _libc_sem_getvalue(sem_t * __restrict sem, int * __restrict sval);
extern int _libc_sem_trywait(sem_t *sem);
extern int _libc_sem_wait(sem_t *sem);
extern int _libc_sem_timedwait(sem_t * __restrict sem,
const struct timespec * __restrict abstime);
extern int _libc_sem_post(sem_t *sem);
int
_sem_init(sem_t *sem, int pshared, unsigned int value)
{
return _libc_sem_init(sem, pshared, value);
}
int
_sem_destroy(sem_t *sem)
{
return _libc_sem_destroy(sem);
}
int
_sem_getvalue(sem_t * __restrict sem, int * __restrict sval)
{
return _libc_sem_getvalue(sem, sval);
}
int
_sem_trywait(sem_t *sem)
{
return _libc_sem_trywait(sem);
}
int
_sem_wait(sem_t *sem)
{
return _libc_sem_wait(sem);
}
int
_sem_timedwait(sem_t * __restrict sem,
const struct timespec * __restrict abstime)
{
return _libc_sem_timedwait(sem, abstime);
}
int
_sem_post(sem_t *sem)
{
return _libc_sem_post(sem);
}

1
sys/kern/uipc_sem.c
View file

@ -51,7 +51,6 @@ __FBSDID("$FreeBSD$");
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/posix4.h>
#include <sys/semaphore.h>
#include <sys/_semaphore.h>
#include <sys/stat.h>
#include <sys/syscall.h>

21
sys/sys/_semaphore.h
View file

@ -31,27 +31,10 @@
typedef intptr_t semid_t;
struct timespec;
#define SEM_VALUE_MAX __INT_MAX
#ifndef _KERNEL
#include <sys/cdefs.h>
/*
* Semaphore definitions.
*/
struct sem {
#define SEM_MAGIC ((u_int32_t) 0x09fa4012)
u_int32_t magic;
pthread_mutex_t lock;
pthread_cond_t gtzero;
u_int32_t count;
u_int32_t nwaiters;
#define SEM_USER (NULL)
semid_t semid; /* semaphore id if kernel (shared) semaphore */
int syssem; /* 1 if kernel (shared) semaphore */
LIST_ENTRY(sem) entry;
struct sem **backpointer;
};
__BEGIN_DECLS
int ksem_close(semid_t id);

69
sys/sys/semaphore.h
View file

@ -1,69 +0,0 @@
/*-
* Copyright (c) 1996, 1997
* HD Associates, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by HD Associates, Inc
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* 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.
*
* $FreeBSD$
*/
/* semaphore.h: POSIX 1003.1b semaphores */
#ifndef _SEMAPHORE_H_
#define _SEMAPHORE_H_
#include <machine/_limits.h>
/* Opaque type definition. */
struct sem;
typedef struct sem * sem_t;
#define SEM_FAILED ((sem_t *)0)
#define SEM_VALUE_MAX __INT_MAX
#ifndef _KERNEL
#include <sys/cdefs.h>
struct timespec;
__BEGIN_DECLS
int sem_close(sem_t *);
int sem_destroy(sem_t *);
int sem_getvalue(sem_t * __restrict, int * __restrict);
int sem_init(sem_t *, int, unsigned int);
sem_t *sem_open(const char *, int, ...);
int sem_post(sem_t *);
int sem_timedwait(sem_t * __restrict, const struct timespec * __restrict);
int sem_trywait(sem_t *);
int sem_unlink(const char *);
int sem_wait(sem_t *);
__END_DECLS
#endif
#endif /* !_SEMAPHORE_H_ */