glibc/sysdeps/unix/sysv/linux/futex-internal.h
Paul Eggert 5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
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
2019-09-07 02:43:31 -07:00

256 lines
8.3 KiB
C

/* futex operations for glibc-internal use. Linux version.
Copyright (C) 2014-2019 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 FUTEX_INTERNAL_H
#define FUTEX_INTERNAL_H
#include <sysdeps/nptl/futex-internal.h>
#include <errno.h>
#include <lowlevellock-futex.h>
#include <sysdep-cancel.h>
/* See sysdeps/nptl/futex-internal.h for documentation; this file only
contains Linux-specific comments.
The Linux kernel treats provides absolute timeouts based on the
CLOCK_REALTIME clock and relative timeouts measured against the
CLOCK_MONOTONIC clock.
We expect a Linux kernel version of 2.6.22 or more recent (since this
version, EINTR is not returned on spurious wake-ups anymore). */
/* FUTEX_SHARED is always supported by the Linux kernel. */
static __always_inline int
futex_supports_pshared (int pshared)
{
if (__glibc_likely (pshared == PTHREAD_PROCESS_PRIVATE))
return 0;
else if (pshared == PTHREAD_PROCESS_SHARED)
return 0;
else
return EINVAL;
}
/* See sysdeps/nptl/futex-internal.h for details. */
static __always_inline int
futex_wait (unsigned int *futex_word, unsigned int expected, int private)
{
int err = lll_futex_timed_wait (futex_word, expected, NULL, private);
switch (err)
{
case 0:
case -EAGAIN:
case -EINTR:
return -err;
case -ETIMEDOUT: /* Cannot have happened as we provided no timeout. */
case -EFAULT: /* Must have been caused by a glibc or application bug. */
case -EINVAL: /* Either due to wrong alignment or due to the timeout not
being normalized. Must have been caused by a glibc or
application bug. */
case -ENOSYS: /* Must have been caused by a glibc bug. */
/* No other errors are documented at this time. */
default:
futex_fatal_error ();
}
}
/* See sysdeps/nptl/futex-internal.h for details. */
static __always_inline int
futex_wait_cancelable (unsigned int *futex_word, unsigned int expected,
int private)
{
int oldtype;
oldtype = __pthread_enable_asynccancel ();
int err = lll_futex_timed_wait (futex_word, expected, NULL, private);
__pthread_disable_asynccancel (oldtype);
switch (err)
{
case 0:
case -EAGAIN:
case -EINTR:
return -err;
case -ETIMEDOUT: /* Cannot have happened as we provided no timeout. */
case -EFAULT: /* Must have been caused by a glibc or application bug. */
case -EINVAL: /* Either due to wrong alignment or due to the timeout not
being normalized. Must have been caused by a glibc or
application bug. */
case -ENOSYS: /* Must have been caused by a glibc bug. */
/* No other errors are documented at this time. */
default:
futex_fatal_error ();
}
}
/* See sysdeps/nptl/futex-internal.h for details. */
static __always_inline int
futex_reltimed_wait (unsigned int *futex_word, unsigned int expected,
const struct timespec *reltime, int private)
{
int err = lll_futex_timed_wait (futex_word, expected, reltime, private);
switch (err)
{
case 0:
case -EAGAIN:
case -EINTR:
case -ETIMEDOUT:
return -err;
case -EFAULT: /* Must have been caused by a glibc or application bug. */
case -EINVAL: /* Either due to wrong alignment or due to the timeout not
being normalized. Must have been caused by a glibc or
application bug. */
case -ENOSYS: /* Must have been caused by a glibc bug. */
/* No other errors are documented at this time. */
default:
futex_fatal_error ();
}
}
/* See sysdeps/nptl/futex-internal.h for details. */
static __always_inline int
futex_reltimed_wait_cancelable (unsigned int *futex_word,
unsigned int expected,
const struct timespec *reltime, int private)
{
int oldtype;
oldtype = LIBC_CANCEL_ASYNC ();
int err = lll_futex_timed_wait (futex_word, expected, reltime, private);
LIBC_CANCEL_RESET (oldtype);
switch (err)
{
case 0:
case -EAGAIN:
case -EINTR:
case -ETIMEDOUT:
return -err;
case -EFAULT: /* Must have been caused by a glibc or application bug. */
case -EINVAL: /* Either due to wrong alignment or due to the timeout not
being normalized. Must have been caused by a glibc or
application bug. */
case -ENOSYS: /* Must have been caused by a glibc bug. */
/* No other errors are documented at this time. */
default:
futex_fatal_error ();
}
}
/* See sysdeps/nptl/futex-internal.h for details. */
static __always_inline int
futex_abstimed_supported_clockid (clockid_t clockid)
{
return lll_futex_supported_clockid (clockid);
}
/* See sysdeps/nptl/futex-internal.h for details. */
static __always_inline int
futex_abstimed_wait (unsigned int *futex_word, unsigned int expected,
clockid_t clockid,
const struct timespec *abstime, int private)
{
/* Work around the fact that the kernel rejects negative timeout values
despite them being valid. */
if (__glibc_unlikely ((abstime != NULL) && (abstime->tv_sec < 0)))
return ETIMEDOUT;
int err = lll_futex_clock_wait_bitset (futex_word, expected,
clockid, abstime,
private);
switch (err)
{
case 0:
case -EAGAIN:
case -EINTR:
case -ETIMEDOUT:
return -err;
case -EFAULT: /* Must have been caused by a glibc or application bug. */
case -EINVAL: /* Either due to wrong alignment, unsupported
clockid or due to the timeout not being
normalized. Must have been caused by a glibc or
application bug. */
case -ENOSYS: /* Must have been caused by a glibc bug. */
/* No other errors are documented at this time. */
default:
futex_fatal_error ();
}
}
/* See sysdeps/nptl/futex-internal.h for details. */
static __always_inline int
futex_abstimed_wait_cancelable (unsigned int *futex_word,
unsigned int expected,
clockid_t clockid,
const struct timespec *abstime, int private)
{
/* Work around the fact that the kernel rejects negative timeout values
despite them being valid. */
if (__glibc_unlikely ((abstime != NULL) && (abstime->tv_sec < 0)))
return ETIMEDOUT;
int oldtype;
oldtype = __pthread_enable_asynccancel ();
int err = lll_futex_clock_wait_bitset (futex_word, expected,
clockid, abstime,
private);
__pthread_disable_asynccancel (oldtype);
switch (err)
{
case 0:
case -EAGAIN:
case -EINTR:
case -ETIMEDOUT:
return -err;
case -EFAULT: /* Must have been caused by a glibc or application bug. */
case -EINVAL: /* Either due to wrong alignment or due to the timeout not
being normalized. Must have been caused by a glibc or
application bug. */
case -ENOSYS: /* Must have been caused by a glibc bug. */
/* No other errors are documented at this time. */
default:
futex_fatal_error ();
}
}
/* See sysdeps/nptl/futex-internal.h for details. */
static __always_inline void
futex_wake (unsigned int *futex_word, int processes_to_wake, int private)
{
int res = lll_futex_wake (futex_word, processes_to_wake, private);
/* No error. Ignore the number of woken processes. */
if (res >= 0)
return;
switch (res)
{
case -EFAULT: /* Could have happened due to memory reuse. */
case -EINVAL: /* Could be either due to incorrect alignment (a bug in
glibc or in the application) or due to memory being
reused for a PI futex. We cannot distinguish between the
two causes, and one of them is correct use, so we do not
act in this case. */
return;
case -ENOSYS: /* Must have been caused by a glibc bug. */
/* No other errors are documented at this time. */
default:
futex_fatal_error ();
}
}
#endif /* futex-internal.h */