glibc/sysdeps/pthread/tst-create1.c
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

124 lines
3.4 KiB
C

/* Verify that pthread_create does not deadlock when ctors take locks.
Copyright (C) 2021-2022 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/>. */
#include <stdio.h>
#include <support/xdlfcn.h>
#include <support/xthread.h>
/*
Check if ctor and pthread_create deadlocks in
thread 1: dlopen -> ctor -> lock(user_lock)
thread 2: lock(user_lock) -> pthread_create
or in
thread 1: dlclose -> dtor -> lock(user_lock)
thread 2: lock(user_lock) -> pthread_create
*/
static pthread_barrier_t bar_ctor;
static pthread_barrier_t bar_ctor_finish;
static pthread_barrier_t bar_dtor;
static pthread_mutex_t user_lock = PTHREAD_MUTEX_INITIALIZER;
void
ctor (void)
{
xpthread_barrier_wait (&bar_ctor);
dprintf (1, "thread 1: in ctor: started.\n");
xpthread_mutex_lock (&user_lock);
dprintf (1, "thread 1: in ctor: locked user_lock.\n");
xpthread_mutex_unlock (&user_lock);
dprintf (1, "thread 1: in ctor: unlocked user_lock.\n");
dprintf (1, "thread 1: in ctor: done.\n");
xpthread_barrier_wait (&bar_ctor_finish);
}
void
dtor (void)
{
xpthread_barrier_wait (&bar_dtor);
dprintf (1, "thread 1: in dtor: started.\n");
xpthread_mutex_lock (&user_lock);
dprintf (1, "thread 1: in dtor: locked user_lock.\n");
xpthread_mutex_unlock (&user_lock);
dprintf (1, "thread 1: in dtor: unlocked user_lock.\n");
dprintf (1, "thread 1: in dtor: done.\n");
}
static void *
thread3 (void *a)
{
dprintf (1, "thread 3: started.\n");
dprintf (1, "thread 3: done.\n");
return 0;
}
static void *
thread2 (void *a)
{
pthread_t t3;
dprintf (1, "thread 2: started.\n");
xpthread_mutex_lock (&user_lock);
dprintf (1, "thread 2: locked user_lock.\n");
xpthread_barrier_wait (&bar_ctor);
t3 = xpthread_create (0, thread3, 0);
xpthread_mutex_unlock (&user_lock);
dprintf (1, "thread 2: unlocked user_lock.\n");
xpthread_join (t3);
xpthread_barrier_wait (&bar_ctor_finish);
xpthread_mutex_lock (&user_lock);
dprintf (1, "thread 2: locked user_lock.\n");
xpthread_barrier_wait (&bar_dtor);
t3 = xpthread_create (0, thread3, 0);
xpthread_mutex_unlock (&user_lock);
dprintf (1, "thread 2: unlocked user_lock.\n");
xpthread_join (t3);
dprintf (1, "thread 2: done.\n");
return 0;
}
static void
thread1 (void)
{
dprintf (1, "thread 1: started.\n");
xpthread_barrier_init (&bar_ctor, NULL, 2);
xpthread_barrier_init (&bar_ctor_finish, NULL, 2);
xpthread_barrier_init (&bar_dtor, NULL, 2);
pthread_t t2 = xpthread_create (0, thread2, 0);
void *p = xdlopen ("tst-create1mod.so", RTLD_NOW | RTLD_GLOBAL);
dprintf (1, "thread 1: dlopen done.\n");
xdlclose (p);
dprintf (1, "thread 1: dlclose done.\n");
xpthread_join (t2);
dprintf (1, "thread 1: done.\n");
}
static int
do_test (void)
{
thread1 ();
return 0;
}
#include <support/test-driver.c>