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

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General further adoption of SPDX licensing ID tags. Mainly focus on files that use BSD 3-Clause license. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts. Special thanks to Wind River for providing access to "The Duke of Highlander" tool: an older (2014) run over FreeBSD tree was useful as a starting point.
2017-11-20 19:49:47 +00:00
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
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.
Remove 3rd clause, renumber, ok per email
2007-01-12 07:31:30 +00:00
* 3. Neither the name of the author nor the names of any co-contributors
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
* 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.
*/
Fix SCM ID's.
2002-02-01 00:57:29 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
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"
Properly interpose libc spinlocks, was missed in r276630. In particular, stdio locking was affected. Reported and tested by: "Matthew D. Fuller" <fullermd@over-yonder.net> Sponsored by: The FreeBSD Foundation MFC after: 3 days
2015-02-14 11:47:40 +00:00
#include "libc_private.h"
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
Add prototypes for libc private interfaces. While I'm there, apply __unused whenever appropriate. Reviewed by: md5(1)
2010-03-31 18:36:04 +00:00
long _atomic_lock_stub(volatile long *);
void _spinlock_stub(spinlock_t *);
void _spinunlock_stub(spinlock_t *);
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);
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
long
Add prototypes for libc private interfaces. While I'm there, apply __unused whenever appropriate. Reviewed by: md5(1)
2010-03-31 18:36:04 +00:00
_atomic_lock_stub(volatile long *lck __unused)
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
{
return (0L);
}
Properly interpose libc spinlocks, was missed in r276630. In particular, stdio locking was affected. Reported and tested by: "Matthew D. Fuller" <fullermd@over-yonder.net> Sponsored by: The FreeBSD Foundation MFC after: 3 days
2015-02-14 11:47:40 +00:00
#pragma weak _spinlock
void
_spinlock(spinlock_t *lck)
{
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
Properly interpose libc spinlocks, was missed in r276630. In particular, stdio locking was affected. Reported and tested by: "Matthew D. Fuller" <fullermd@over-yonder.net> Sponsored by: The FreeBSD Foundation MFC after: 3 days
2015-02-14 11:47:40 +00:00
((void (*)(spinlock_t *lck))__libc_interposing[INTERPOS_spinlock])
(lck);
}
Fix typo. Note that this is mostly innocent, since libthr no longer interposes the symbol. Noted by: rpaulo MFC after: 3 days
2015-02-27 19:23:01 +00:00
#pragma weak _spinunlock
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
Properly interpose libc spinlocks, was missed in r276630. In particular, stdio locking was affected. Reported and tested by: "Matthew D. Fuller" <fullermd@over-yonder.net> Sponsored by: The FreeBSD Foundation MFC after: 3 days
2015-02-14 11:47:40 +00:00
_spinunlock(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
{
Properly interpose libc spinlocks, was missed in r276630. In particular, stdio locking was affected. Reported and tested by: "Matthew D. Fuller" <fullermd@over-yonder.net> Sponsored by: The FreeBSD Foundation MFC after: 3 days
2015-02-14 11:47:40 +00:00
((void (*)(spinlock_t *lck))__libc_interposing[INTERPOS_spinunlock])
(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
}
- Define a _spinunlock() function so that threading implementations may do more complicated things than just setting the lock to 0. - Implement stubs for this function in libc and the two threading libraries that are currently in the tree.
2003-03-26 04:02:24 +00:00
void
Properly interpose libc spinlocks, was missed in r276630. In particular, stdio locking was affected. Reported and tested by: "Matthew D. Fuller" <fullermd@over-yonder.net> Sponsored by: The FreeBSD Foundation MFC after: 3 days
2015-02-14 11:47:40 +00:00
__libc_spinlock_stub(spinlock_t *lck __unused)
- Define a _spinunlock() function so that threading implementations may do more complicated things than just setting the lock to 0. - Implement stubs for this function in libc and the two threading libraries that are currently in the tree.
2003-03-26 04:02:24 +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
void
Properly interpose libc spinlocks, was missed in r276630. In particular, stdio locking was affected. Reported and tested by: "Matthew D. Fuller" <fullermd@over-yonder.net> Sponsored by: The FreeBSD Foundation MFC after: 3 days
2015-02-14 11:47:40 +00:00
__libc_spinunlock_stub(spinlock_t *lck __unused)
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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