/* $NetBSD: reentrant.h,v 1.13 2008/04/28 20:23:00 martin Exp $ */ /*- * Copyright (c) 1997, 1998, 2003 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by J.T. Conklin, by Nathan J. Williams, and by Jason R. Thorpe. * * 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. */ /* * 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 efficent 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 thread primitives used by the library (mutex_t, mutex_lock, etc.) * are macros which expand to the cooresponding 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 thread 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. * * The thread functions operate by dispatching to symbols which are, by * default, weak-aliased to no-op functions in thread-stub/thread-stub.c * (some uses of thread operations are conditional on __isthreaded, but * not all of them are). * * When the thread library is linked in, it provides strong-alias versions * of those symbols which dispatch to its own real thread operations. * */ #ifdef _REENTRANT /* * Abstract thread interface for thread-safe libraries. These routines * will use stubs in libc if the application is not linked against the * pthread library, and the real function in the pthread library if it * is. */ #include #include #define mutex_t pthread_mutex_t #define MUTEX_INITIALIZER PTHREAD_MUTEX_INITIALIZER #define mutexattr_t pthread_mutexattr_t #define MUTEX_TYPE_NORMAL PTHREAD_MUTEX_NORMAL #define MUTEX_TYPE_ERRORCHECK PTHREAD_MUTEX_ERRORCHECK #define MUTEX_TYPE_RECURSIVE PTHREAD_MUTEX_RECURSIVE #define cond_t pthread_cond_t #define COND_INITIALIZER PTHREAD_COND_INITIALIZER #define condattr_t pthread_condattr_t #define rwlock_t pthread_rwlock_t #define RWLOCK_INITIALIZER PTHREAD_RWLOCK_INITIALIZER #define rwlockattr_t pthread_rwlockattr_t #define thread_key_t pthread_key_t #define thr_t pthread_t #define thrattr_t pthread_attr_t #define once_t pthread_once_t #define ONCE_INITIALIZER PTHREAD_ONCE_INIT #ifndef __LIBC_THREAD_STUBS __BEGIN_DECLS int __libc_mutex_init(mutex_t *, const mutexattr_t *); int __libc_mutex_lock(mutex_t *); int __libc_mutex_trylock(mutex_t *); int __libc_mutex_unlock(mutex_t *); int __libc_mutex_destroy(mutex_t *); int __libc_mutexattr_init(mutexattr_t *); int __libc_mutexattr_settype(mutexattr_t *, int); int __libc_mutexattr_destroy(mutexattr_t *); __END_DECLS #define mutex_init(m, a) __libc_mutex_init((m), (a)) #define mutex_lock(m) __libc_mutex_lock((m)) #define mutex_trylock(m) __libc_mutex_trylock((m)) #define mutex_unlock(m) __libc_mutex_unlock((m)) #define mutex_destroy(m) __libc_mutex_destroy((m)) #define mutexattr_init(ma) __libc_mutexattr_init((ma)) #define mutexattr_settype(ma, t) __libc_mutexattr_settype((ma), (t)) #define mutexattr_destroy(ma) __libc_mutexattr_destroy((ma)) __BEGIN_DECLS int __libc_cond_init(cond_t *, const condattr_t *); int __libc_cond_signal(cond_t *); int __libc_cond_broadcast(cond_t *); int __libc_cond_wait(cond_t *, mutex_t *); int __libc_cond_timedwait(cond_t *, mutex_t *, const struct timespec *); int __libc_cond_destroy(cond_t *); __END_DECLS #define cond_init(c, t, a) __libc_cond_init((c), (a)) #define cond_signal(c) __libc_cond_signal((c)) #define cond_broadcast(c) __libc_cond_broadcast((c)) #define cond_wait(c, m) __libc_cond_wait((c), (m)) #define cond_timedwait(c, m, t) __libc_cond_timedwait((c), (m), (t)) #define cond_destroy(c) __libc_cond_destroy((c)) __BEGIN_DECLS int __libc_rwlock_init(rwlock_t *, const rwlockattr_t *); int __libc_rwlock_rdlock(rwlock_t *); int __libc_rwlock_wrlock(rwlock_t *); int __libc_rwlock_tryrdlock(rwlock_t *); int __libc_rwlock_trywrlock(rwlock_t *); int __libc_rwlock_unlock(rwlock_t *); int __libc_rwlock_destroy(rwlock_t *); __END_DECLS #define rwlock_init(l, a) __libc_rwlock_init((l), (a)) #define rwlock_rdlock(l) __libc_rwlock_rdlock((l)) #define rwlock_wrlock(l) __libc_rwlock_wrlock((l)) #define rwlock_tryrdlock(l) __libc_rwlock_tryrdlock((l)) #define rwlock_trywrlock(l) __libc_rwlock_trywrlock((l)) #define rwlock_unlock(l) __libc_rwlock_unlock((l)) #define rwlock_destroy(l) __libc_rwlock_destroy((l)) __BEGIN_DECLS int __libc_thr_keycreate(thread_key_t *, void (*)(void *)); int __libc_thr_setspecific(thread_key_t, const void *); void *__libc_thr_getspecific(thread_key_t); int __libc_thr_keydelete(thread_key_t); __END_DECLS #define thr_keycreate(k, d) __libc_thr_keycreate((k), (d)) #define thr_setspecific(k, p) __libc_thr_setspecific((k), (p)) #define thr_getspecific(k) __libc_thr_getspecific((k)) #define thr_keydelete(k) __libc_thr_keydelete((k)) __BEGIN_DECLS int __libc_thr_once(once_t *, void (*)(void)); int __libc_thr_sigsetmask(int, const sigset_t *, sigset_t *); thr_t __libc_thr_self(void); int __libc_thr_yield(void); void __libc_thr_create(thr_t *, const thrattr_t *, void *(*)(void *), void *); void __libc_thr_exit(void *) __attribute__((__noreturn__)); int *__libc_thr_errno(void); int __libc_thr_setcancelstate(int, int *); unsigned int __libc_thr_curcpu(void); extern int __isthreaded; __END_DECLS #define thr_once(o, f) __libc_thr_once((o), (f)) #define thr_sigsetmask(f, n, o) __libc_thr_sigsetmask((f), (n), (o)) #define thr_self() __libc_thr_self() #define thr_yield() __libc_thr_yield() #define thr_create(tp, ta, f, a) __libc_thr_create((tp), (ta), (f), (a)) #define thr_exit(v) __libc_thr_exit((v)) #define thr_errno() __libc_thr_errno() #define thr_enabled() (__isthreaded) #define thr_setcancelstate(n, o) __libc_thr_setcancelstate((n),(o)) #define thr_curcpu() __libc_thr_curcpu() #endif /* __LIBC_THREAD_STUBS */ #define FLOCKFILE(fp) __flockfile_internal(fp, 1) #define FUNLOCKFILE(fp) __funlockfile_internal(fp, 1) #else /* _REENTRANT */ #define mutex_init(m, a) #define mutex_lock(m) #define mutex_trylock(m) #define mutex_unlock(m) #define mutex_destroy(m) #define cond_init(c, t, a) #define cond_signal(c) #define cond_broadcast(c) #define cond_wait(c, m) #define cond_timedwait(c, m, t) #define cond_destroy(c) #define rwlock_init(l, a) #define rwlock_rdlock(l) #define rwlock_wrlock(l) #define rwlock_tryrdlock(l) #define rwlock_trywrlock(l) #define rwlock_unlock(l) #define rwlock_destroy(l) #define thr_keycreate(k, d) #define thr_setspecific(k, p) #define thr_getspecific(k) #define thr_keydelete(k) #define thr_once(o, f) #define thr_sigsetmask(f, n, o) #define thr_self() #define thr_errno() #define thr_curcpu() ((unsigned int)0) #define FLOCKFILE(fp) #define FUNLOCKFILE(fp) #endif /* _REENTRANT */