mirror of
git://sourceware.org/git/glibc.git
synced 2024-11-21 01:12:26 +08:00
5a82c74822
Also, change sources.redhat.com to sourceware.org. This patch was automatically generated by running the following shell script, which uses GNU sed, and which avoids modifying files imported from upstream: sed -ri ' s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g ' \ $(find $(git ls-files) -prune -type f \ ! -name '*.po' \ ! -name 'ChangeLog*' \ ! -path COPYING ! -path COPYING.LIB \ ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \ ! -path manual/texinfo.tex ! -path scripts/config.guess \ ! -path scripts/config.sub ! -path scripts/install-sh \ ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \ ! -path INSTALL ! -path locale/programs/charmap-kw.h \ ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \ ! '(' -name configure \ -execdir test -f configure.ac -o -f configure.in ';' ')' \ ! '(' -name preconfigure \ -execdir test -f preconfigure.ac ';' ')' \ -print) and then by running 'make dist-prepare' to regenerate files built from the altered files, and then executing the following to cleanup: chmod a+x sysdeps/unix/sysv/linux/riscv/configure # Omit irrelevant whitespace and comment-only changes, # perhaps from a slightly-different Autoconf version. git checkout -f \ sysdeps/csky/configure \ sysdeps/hppa/configure \ sysdeps/riscv/configure \ sysdeps/unix/sysv/linux/csky/configure # Omit changes that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines git checkout -f \ sysdeps/powerpc/powerpc64/ppc-mcount.S \ sysdeps/unix/sysv/linux/s390/s390-64/syscall.S # Omit change that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
102 lines
3.1 KiB
C
102 lines
3.1 KiB
C
/* sem_wait -- wait on a semaphore. Generic futex-using version.
|
|
Copyright (C) 2003-2019 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
|
|
|
|
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 <lowlevellock.h> /* lll_futex* used by the old code. */
|
|
#include "sem_waitcommon.c"
|
|
|
|
int
|
|
__new_sem_wait (sem_t *sem)
|
|
{
|
|
/* We need to check whether we need to act upon a cancellation request here
|
|
because POSIX specifies that cancellation points "shall occur" in
|
|
sem_wait and sem_timedwait, which also means that they need to check
|
|
this regardless whether they block or not (unlike "may occur"
|
|
functions). See the POSIX Rationale for this requirement: Section
|
|
"Thread Cancellation Overview" [1] and austin group issue #1076 [2]
|
|
for thoughs on why this may be a suboptimal design.
|
|
|
|
[1] http://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xsh_chap02.html
|
|
[2] http://austingroupbugs.net/view.php?id=1076 for thoughts on why this
|
|
*/
|
|
__pthread_testcancel ();
|
|
|
|
if (__new_sem_wait_fast ((struct new_sem *) sem, 0) == 0)
|
|
return 0;
|
|
else
|
|
return __new_sem_wait_slow ((struct new_sem *) sem,
|
|
CLOCK_REALTIME, NULL);
|
|
}
|
|
versioned_symbol (libpthread, __new_sem_wait, sem_wait, GLIBC_2_1);
|
|
|
|
#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1)
|
|
int
|
|
attribute_compat_text_section
|
|
__old_sem_wait (sem_t *sem)
|
|
{
|
|
int *futex = (int *) sem;
|
|
int err;
|
|
|
|
do
|
|
{
|
|
if (atomic_decrement_if_positive (futex) > 0)
|
|
return 0;
|
|
|
|
/* Always assume the semaphore is shared. */
|
|
err = lll_futex_wait_cancel (futex, 0, LLL_SHARED);
|
|
}
|
|
while (err == 0 || err == -EWOULDBLOCK);
|
|
|
|
__set_errno (-err);
|
|
return -1;
|
|
}
|
|
|
|
compat_symbol (libpthread, __old_sem_wait, sem_wait, GLIBC_2_0);
|
|
#endif
|
|
|
|
int
|
|
__new_sem_trywait (sem_t *sem)
|
|
{
|
|
/* We must not fail spuriously, so require a definitive result even if this
|
|
may lead to a long execution time. */
|
|
if (__new_sem_wait_fast ((struct new_sem *) sem, 1) == 0)
|
|
return 0;
|
|
__set_errno (EAGAIN);
|
|
return -1;
|
|
}
|
|
versioned_symbol (libpthread, __new_sem_trywait, sem_trywait, GLIBC_2_1);
|
|
#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1)
|
|
int
|
|
__old_sem_trywait (sem_t *sem)
|
|
{
|
|
int *futex = (int *) sem;
|
|
int val;
|
|
|
|
if (*futex > 0)
|
|
{
|
|
val = atomic_decrement_if_positive (futex);
|
|
if (val > 0)
|
|
return 0;
|
|
}
|
|
|
|
__set_errno (EAGAIN);
|
|
return -1;
|
|
}
|
|
compat_symbol (libpthread, __old_sem_trywait, sem_trywait, GLIBC_2_0);
|
|
#endif
|