d52a982ea8
- duplicate words - typos - references to old versions of FreeBSD Reviewed by: imp, benno
131 lines
5.0 KiB
C
131 lines
5.0 KiB
C
/*-
|
|
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
|
|
*
|
|
* Copyright (c) 1997,98 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
|
* by J.T. Conklin.
|
|
*
|
|
* 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.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
/*
|
|
* Requirements:
|
|
*
|
|
* 1. The thread safe mechanism should be lightweight so the library can
|
|
* be used by non-threaded applications without unreasonable overhead.
|
|
*
|
|
* 2. There should be no dependency on a thread engine for non-threaded
|
|
* applications.
|
|
*
|
|
* 3. There should be no dependency on any particular thread engine.
|
|
*
|
|
* 4. The library should be able to be compiled without support for thread
|
|
* safety.
|
|
*
|
|
*
|
|
* Rationale:
|
|
*
|
|
* One approach for thread safety is to provide discrete versions of the
|
|
* library: one thread safe, the other not. The disadvantage of this is
|
|
* that libc is rather large, and two copies of a library which are 99%+
|
|
* identical is not an efficient use of resources.
|
|
*
|
|
* Another approach is to provide a single thread safe library. However,
|
|
* it should not add significant run time or code size overhead to non-
|
|
* threaded applications.
|
|
*
|
|
* Since the NetBSD C library is used in other projects, it should be
|
|
* easy to replace the mutual exclusion primitives with ones provided by
|
|
* another system. Similarly, it should also be easy to remove all
|
|
* support for thread safety completely if the target environment does
|
|
* not support threads.
|
|
*
|
|
*
|
|
* Implementation Details:
|
|
*
|
|
* The mutex primitives used by the library (mutex_t, mutex_lock, etc.)
|
|
* are macros which expand to the corresponding primitives provided by
|
|
* the thread engine or to nothing. The latter is used so that code is
|
|
* not unreasonably cluttered with #ifdefs when all thread safe support
|
|
* is removed.
|
|
*
|
|
* The mutex macros can be directly mapped to the mutex primitives from
|
|
* pthreads, however it should be reasonably easy to wrap another mutex
|
|
* implementation so it presents a similar interface.
|
|
*
|
|
* Stub implementations of the mutex functions are provided with *weak*
|
|
* linkage. These functions simply return success. When linked with a
|
|
* thread library (i.e. -lpthread), the functions will override the
|
|
* stubs.
|
|
*/
|
|
|
|
#include <pthread.h>
|
|
#include <pthread_np.h>
|
|
#include "libc_private.h"
|
|
|
|
#define mutex_t pthread_mutex_t
|
|
#define cond_t pthread_cond_t
|
|
#define rwlock_t pthread_rwlock_t
|
|
#define once_t pthread_once_t
|
|
|
|
#define thread_key_t pthread_key_t
|
|
#define MUTEX_INITIALIZER PTHREAD_MUTEX_INITIALIZER
|
|
#define RWLOCK_INITIALIZER PTHREAD_RWLOCK_INITIALIZER
|
|
#define ONCE_INITIALIZER PTHREAD_ONCE_INIT
|
|
|
|
#define mutex_init(m, a) _pthread_mutex_init(m, a)
|
|
#define mutex_lock(m) if (__isthreaded) \
|
|
_pthread_mutex_lock(m)
|
|
#define mutex_unlock(m) if (__isthreaded) \
|
|
_pthread_mutex_unlock(m)
|
|
#define mutex_trylock(m) (__isthreaded ? 0 : _pthread_mutex_trylock(m))
|
|
|
|
#define cond_init(c, a, p) _pthread_cond_init(c, a)
|
|
#define cond_signal(m) if (__isthreaded) \
|
|
_pthread_cond_signal(m)
|
|
#define cond_broadcast(m) if (__isthreaded) \
|
|
_pthread_cond_broadcast(m)
|
|
#define cond_wait(c, m) if (__isthreaded) \
|
|
_pthread_cond_wait(c, m)
|
|
|
|
#define rwlock_init(l, a) _pthread_rwlock_init(l, a)
|
|
#define rwlock_rdlock(l) if (__isthreaded) \
|
|
_pthread_rwlock_rdlock(l)
|
|
#define rwlock_wrlock(l) if (__isthreaded) \
|
|
_pthread_rwlock_wrlock(l)
|
|
#define rwlock_unlock(l) if (__isthreaded) \
|
|
_pthread_rwlock_unlock(l)
|
|
|
|
#define thr_keycreate(k, d) _pthread_key_create(k, d)
|
|
#define thr_setspecific(k, p) _pthread_setspecific(k, p)
|
|
#define thr_getspecific(k) _pthread_getspecific(k)
|
|
#define thr_sigsetmask(f, n, o) _pthread_sigmask(f, n, o)
|
|
|
|
#define thr_once(o, i) _pthread_once(o, i)
|
|
#define thr_self() _pthread_self()
|
|
#define thr_exit(x) _pthread_exit(x)
|
|
#define thr_main() _pthread_main_np()
|