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/*
* Berkeley Lab Checkpoint/Restart (BLCR) for Linux is Copyright (c)
* 2003, The Regents of the University of California, through Lawrence
* Berkeley National Laboratory (subject to receipt of any required
* approvals from the U.S. Dept. of Energy). All rights reserved.
*
* Portions may be copyrighted by others, as may be noted in specific
* copyright notices within specific files.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id: cr_pthread.c,v 1.31 2007/09/20 23:53:34 phargrov Exp $
*/
#include <string.h>
#include <stdlib.h>
#include <dlfcn.h>
#include <errno.h>
#include "cr_private.h"
#if PIC && HAVE___REGISTER_ATFORK
// pthread_atfork() handling for shared objects
// glibc has started putting pthread_atfork() in libpthread_nonshared.a, which is causing
// problems when we call from a shared library. The problem is that the code in the
// static lib gets pulled into libcr.so, but its was not PIC-compiled.
// Therefore, we use our own private re-implementation.
// This implementation is closely based on glibc-2.3.2-20030313/nptl/pthread_atfork.c
extern void *__dso_handle __attribute__((__weak__));
extern int __register_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void), void *dso_handle);
extern int
cri_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void))
{
void *my_handle = &__dso_handle ? __dso_handle : NULL;
return __register_atfork(prepare, parent, child, my_handle);
}
#endif
// Holds thread-specific data key for cri_info
pthread_key_t cri_info_key;
// atfork callback to reset the state
static void
child_reset(void)
{
cri_rb_init(&cri_cs_lock);
cri_atomic_write(&cri_live_count, 0);
cri_info_free(cri_info_location());
}
#if !HAVE___REGISTER_ATFORK
// Interpose on fork() to ensure the pthreads version is called
// if the caller linked us, but not the pthreads library.
pid_t cri_fork(void)
{
return __fork();
}
weak_alias(cri_fork,fork);
#endif
//
// Initialize pthread-dependent parts
//
void
cri_pthread_init(void)
{
int rc;
#if !HAVE___REGISTER_ATFORK
// See bug #460
{
// dlopen will fail if this is a static exectuable.
// If so, then the pthread library references must
// have been resolved.
void *handle = dlopen(NULL /* the executable */, RTLD_LAZY);
if (handle) {
if (dlsym(handle, "__fork") == dlsym(handle, "__libc_fork")) {
CRI_ABORT("Unable to ensure pthread_atfork() will run.\n"
"If you dlopen(libcr.so) or use some versions of the libraries/loaders, "
"then you may need to link libpthread explicitly (or use LD_PRELOAD).");
}
dlclose(handle);
}
}
#endif /* !HAVE___REGISTER_ATFORK */
// Install a atfork callback to cleanup state in children
rc = cri_atfork(NULL, NULL, &child_reset);
if (rc != 0) {
CRI_ABORT("cri_atfork() returned %d", rc);
}
// Setup the thread-specific data for cri_info
rc = pthread_key_create(&cri_info_key, &cri_info_free);
if (rc != 0) {
CRI_ABORT("pthread_key_create() returned %d", rc);
}
}
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