glibc/support/timespec.h
Adam Yi 567f7413fb posix: Fix system blocks SIGCHLD erroneously [BZ #30163]
Fix bug that SIGCHLD is erroneously blocked forever in the following
scenario:

1. Thread A calls system but hasn't returned yet
2. Thread B calls another system but returns

SIGCHLD would be blocked forever in thread B after its system() returns,
even after the system() in thread A returns.

Although POSIX does not require, glibc system implementation aims to be
thread and cancellation safe. This bug was introduced in
5fb7fc9635 when we moved reverting signal
mask to happen when the last concurrently running system returns,
despite that signal mask is per thread. This commit reverts this logic
and adds a test.

Signed-off-by: Adam Yi <ayi@janestreet.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
(cherry picked from commit 436a604b7d)
2023-04-28 16:36:24 +02:00

120 lines
4.5 KiB
C

/* Useful functions for tests that use struct timespec.
Copyright (C) 2019-2021 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 SUPPORT_TIMESPEC_H
#define SUPPORT_TIMESPEC_H
#include <stdio.h>
#include <time.h>
#include <support/check.h>
#include <support/xtime.h>
static inline struct timespec
make_timespec (time_t s, long int ns)
{
struct timespec r;
r.tv_sec = s;
r.tv_nsec = ns;
return r;
}
enum { TIMESPEC_HZ = 1000000000 };
#ifndef __USE_TIME_BITS64
struct timespec timespec_add (struct timespec, struct timespec)
__attribute__((const));
struct timespec timespec_sub (struct timespec, struct timespec)
__attribute__((const));
void test_timespec_before_impl (const char *file, int line,
struct timespec left,
struct timespec right);
void test_timespec_equal_or_after_impl (const char *file, int line,
struct timespec left,
struct timespec right);
time_t support_timespec_ns (struct timespec time);
struct timespec support_timespec_normalize (struct timespec time);
int support_timespec_check_in_range (struct timespec expected,
struct timespec observed,
double lower_bound, double upper_bound);
struct timespec dtotimespec (double sec) __attribute__((const));
#else
struct timespec __REDIRECT (timespec_add, (struct timespec, struct timespec),
timespec_add_time64);
struct timespec __REDIRECT (timespec_sub, (struct timespec, struct timespec),
timespec_sub_time64);
void __REDIRECT (test_timespec_before_impl, (const char *file, int line,
struct timespec left,
struct timespec right),
test_timespec_before_impl_time64);
void __REDIRECT (test_timespec_equal_or_after_impl, (const char *f, int line,
struct timespec left,
struct timespec right),
test_timespec_equal_or_after_impl_time64);
time_t __REDIRECT (support_timespec_ns, (struct timespec time),
support_timespec_ns_time64);
struct timespec __REDIRECT (support_timespec_normalize, (struct timespec time),
support_timespec_normalize_time64);
int __REDIRECT (support_timespec_check_in_range, (struct timespec expected,
struct timespec observed,
double lower_bound,
double upper_bound),
support_timespec_check_in_range_time64);
struct timespec __REDIRECT (dtotimespec, (double sec), dtotimespec_time64);
#endif
/* Check that the timespec on the left represents a time before the
time on the right. */
#define TEST_TIMESPEC_BEFORE(left, right) \
test_timespec_before_impl (__FILE__, __LINE__, (left), (right))
#define TEST_TIMESPEC_BEFORE_NOW(left, clockid) \
({ \
struct timespec now; \
const int saved_errno = errno; \
xclock_gettime ((clockid), &now); \
TEST_TIMESPEC_BEFORE ((left), now); \
errno = saved_errno; \
})
/* Check that the timespec on the left represents a time equal to or
after the time on the right. */
#define TEST_TIMESPEC_EQUAL_OR_AFTER(left, right) \
test_timespec_equal_or_after_impl (__FILE__, __LINE__, left, right)
#define TEST_TIMESPEC_NOW_OR_AFTER(clockid, right) \
({ \
struct timespec now; \
const int saved_errno = errno; \
xclock_gettime ((clockid), &now); \
TEST_TIMESPEC_EQUAL_OR_AFTER (now, (right)); \
errno = saved_errno; \
})
#endif /* SUPPORT_TIMESPEC_H */