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freebsd-nq/lib/libc/gen/_spinlock_stub.c

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Stub functions for thread locking with weak symbols so that they are only linked when not linking an application against libc_r or libpthread.
1998-03-09 06:46:21 +00:00
/*
* Copyright (c) 1998 John Birrell <jb@cimlogic.com.au>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by John Birrell.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
$Id$ -> $FreeBSD$
1999-08-28 00:22:10 +00:00
* $FreeBSD$
Stub functions for thread locking with weak symbols so that they are only linked when not linking an application against libc_r or libpthread.
1998-03-09 06:46:21 +00:00
*
*/
#include <stdio.h>
Stubs are required in libc so that it can be used with libpthread (and kernel threads), but weak symbols and non-weak symbols of the same name built into libc_r result in unpredictable linking.
1998-04-29 09:02:16 +00:00
Stub functions for thread locking with weak symbols so that they are only linked when not linking an application against libc_r or libpthread.
1998-03-09 06:46:21 +00:00
#include "spinlock.h"
/*
Remove _THREAD_SAFE and make libc thread-safe by default by adding (weak definitions to) stubs for some of the pthread functions. If the threads library is linked in, the real pthread functions will pulled in. Use the following convention for system calls wrapped by the threads library: __sys_foo - actual system call _foo - weak definition to __sys_foo foo - weak definition to __sys_foo Change all libc uses of system calls wrapped by the threads library from foo to _foo. In order to define the prototypes for _foo(), we introduce namespace.h and un-namespace.h (suggested by bde). All files that need to reference these system calls, should include namespace.h before any standard includes, then include un-namespace.h after the standard includes and before any local includes. <db.h> is an exception and shouldn't be included in between namespace.h and un-namespace.h namespace.h will define foo to _foo, and un-namespace.h will undefine foo. Try to eliminate some of the recursive calls to MT-safe functions in libc/stdio in preparation for adding a mutex to FILE. We have recursive mutexes, but would like to avoid using them if possible. Remove uneeded includes of <errno.h> from a few files. Add $FreeBSD$ to a few files in order to pass commitprep. Approved by: -arch
2001-01-24 13:01:12 +00:00
* Declare weak definitions in case the application is not linked
Stub functions for thread locking with weak symbols so that they are only linked when not linking an application against libc_r or libpthread.
1998-03-09 06:46:21 +00:00
* with libpthread.
*/
To be consistent, use the __weak_reference macro from <sys/cdefs.h> instead of #pragma weak to create weak definitions. This macro is improperly named, though, since a weak definition is not the same thing as a weak reference. Suggested by: bde
2001-04-10 04:11:50 +00:00
__weak_reference(_atomic_lock_stub, _atomic_lock);
__weak_reference(_spinlock_stub, _spinlock);
__weak_reference(_spinlock_debug_stub, _spinlock_debug);
Stub functions for thread locking with weak symbols so that they are only linked when not linking an application against libc_r or libpthread.
1998-03-09 06:46:21 +00:00
Remove _THREAD_SAFE and make libc thread-safe by default by adding (weak definitions to) stubs for some of the pthread functions. If the threads library is linked in, the real pthread functions will pulled in. Use the following convention for system calls wrapped by the threads library: __sys_foo - actual system call _foo - weak definition to __sys_foo foo - weak definition to __sys_foo Change all libc uses of system calls wrapped by the threads library from foo to _foo. In order to define the prototypes for _foo(), we introduce namespace.h and un-namespace.h (suggested by bde). All files that need to reference these system calls, should include namespace.h before any standard includes, then include un-namespace.h after the standard includes and before any local includes. <db.h> is an exception and shouldn't be included in between namespace.h and un-namespace.h namespace.h will define foo to _foo, and un-namespace.h will undefine foo. Try to eliminate some of the recursive calls to MT-safe functions in libc/stdio in preparation for adding a mutex to FILE. We have recursive mutexes, but would like to avoid using them if possible. Remove uneeded includes of <errno.h> from a few files. Add $FreeBSD$ to a few files in order to pass commitprep. Approved by: -arch
2001-01-24 13:01:12 +00:00
/*
* This function is a stub for the _atomic_lock function in libpthread.
*/
long
_atomic_lock_stub(volatile long *lck)
{
return (0L);
}
Stub functions for thread locking with weak symbols so that they are only linked when not linking an application against libc_r or libpthread.
1998-03-09 06:46:21 +00:00
/*
* This function is a stub for the spinlock function in libpthread.
*/
void
Implement compile time debug mode for thread locks.
1998-06-09 08:32:23 +00:00
_spinlock_stub(spinlock_t *lck)
Stub functions for thread locking with weak symbols so that they are only linked when not linking an application against libc_r or libpthread.
1998-03-09 06:46:21 +00:00
{
}
/*
Implement compile time debug mode for thread locks.
1998-06-09 08:32:23 +00:00
* This function is a stub for the debug spinlock function in libpthread.
Stub functions for thread locking with weak symbols so that they are only linked when not linking an application against libc_r or libpthread.
1998-03-09 06:46:21 +00:00
*/
void
Implement compile time debug mode for thread locks.
1998-06-09 08:32:23 +00:00
_spinlock_debug_stub(spinlock_t *lck, char *fname, int lineno)
Stub functions for thread locking with weak symbols so that they are only linked when not linking an application against libc_r or libpthread.
1998-03-09 06:46:21 +00:00
{
}
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