glibc/nptl/tst-barrier4.c
Torvald Riegel b02840bacd New pthread_barrier algorithm to fulfill barrier destruction requirements.
The previous barrier implementation did not fulfill the POSIX requirements
for when a barrier can be destroyed.  Specifically, it was possible that
threads that haven't noticed yet that their round is complete still access
the barrier's memory, and that those accesses can happen after the barrier
has been legally destroyed.
The new algorithm does not have this issue, and it avoids using a lock
internally.
2016-01-15 21:20:34 +01:00

122 lines
2.6 KiB
C

/* Copyright (C) 2004-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
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
<http://www.gnu.org/licenses/>. */
/* This tests destruction of a barrier right after waiting on it. */
#include <errno.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
static pthread_barrier_t b1;
static pthread_barrier_t b2;
#define N 20
static void *
tf (void *arg)
{
int round = 0;
while (round++ < 30)
{
if (pthread_barrier_wait (&b1) == PTHREAD_BARRIER_SERIAL_THREAD)
{
pthread_barrier_destroy (&b1);
if (pthread_barrier_init (&b1, NULL, N) != 0)
{
puts ("tf: 1st barrier_init failed");
exit (1);
}
}
if (pthread_barrier_wait (&b2) == PTHREAD_BARRIER_SERIAL_THREAD)
{
pthread_barrier_destroy (&b2);
if (pthread_barrier_init (&b2, NULL, N) != 0)
{
puts ("tf: 2nd barrier_init failed");
exit (1);
}
}
}
return NULL;
}
static int
do_test (void)
{
pthread_attr_t at;
int cnt;
if (pthread_attr_init (&at) != 0)
{
puts ("attr_init failed");
return 1;
}
if (pthread_attr_setstacksize (&at, 1 * 1024 * 1024) != 0)
{
puts ("attr_setstacksize failed");
return 1;
}
if (pthread_barrier_init (&b1, NULL, N) != 0)
{
puts ("1st barrier_init failed");
return 1;
}
if (pthread_barrier_init (&b2, NULL, N) != 0)
{
puts ("2nd barrier_init failed");
return 1;
}
pthread_t th[N - 1];
for (cnt = 0; cnt < N - 1; ++cnt)
if (pthread_create (&th[cnt], &at, tf, NULL) != 0)
{
puts ("pthread_create failed");
return 1;
}
if (pthread_attr_destroy (&at) != 0)
{
puts ("attr_destroy failed");
return 1;
}
tf (NULL);
for (cnt = 0; cnt < N - 1; ++cnt)
if (pthread_join (th[cnt], NULL) != 0)
{
puts ("pthread_join failed");
return 1;
}
return 0;
}
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"