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/* Basic platform-independent macro definitions for mutexes and

   thread-specific data.

   Copyright (C) 1996, 1997, 1998, 2000 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>, 1996.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, write to the Free

   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA

   02111-1307 USA.  */

/* $Id: thread-m.h,v 1.1 2002/07/15 20:16:31 jjohnstn Exp $

   One out of _LIBC, USE_PTHREADS, USE_THR or USE_SPROC should be

   defined, otherwise the token NO_THREADS and dummy implementations

   of the macros will be defined.  */

#ifndef _THREAD_M_H

#define _THREAD_M_H

#undef thread_atfork_static

#if defined(_LIBC) /* The GNU C library, a special case of Posix threads */

#include <bits/libc-lock.h>

#ifdef PTHREAD_MUTEX_INITIALIZER

typedef pthread_t thread_id;

/* mutex */

typedef pthread_mutex_t mutex_t;

#define MUTEX_INITIALIZER       PTHREAD_MUTEX_INITIALIZER

/* Even if not linking with libpthread, ensure usability of mutex as

   an `in use' flag, see also the NO_THREADS case below.  Assume

   pthread_mutex_t is at least one int wide.  */

#define mutex_init(m)           \

   (__pthread_mutex_init != NULL \

    ? __pthread_mutex_init (m, NULL) : (*(int *)(m) = 0))

#define mutex_lock(m)           \

   (__pthread_mutex_lock != NULL \

    ? __pthread_mutex_lock (m) : ((*(int *)(m) = 1), 0))

#define mutex_trylock(m)        \

   (__pthread_mutex_trylock != NULL \

    ? __pthread_mutex_trylock (m) : (*(int *)(m) ? 1 : ((*(int *)(m) = 1), 0)))

#define mutex_unlock(m)         \

   (__pthread_mutex_unlock != NULL \

    ? __pthread_mutex_unlock (m) : (*(int*)(m) = 0))

#define thread_atfork(prepare, parent, child) \

   (__pthread_atfork != NULL ? __pthread_atfork(prepare, parent, child) : 0)

#elif defined(MUTEX_INITIALIZER)

/* Assume hurd, with cthreads */

/* Cthreads `mutex_t' is a pointer to a mutex, and malloc wants just the

   mutex itself.  */

#undef mutex_t

#define mutex_t struct mutex

#undef mutex_init

#define mutex_init(m) (__mutex_init(m), 0)

#undef mutex_lock

#define mutex_lock(m) (__mutex_lock(m), 0)

#undef mutex_unlock

#define mutex_unlock(m) (__mutex_unlock(m), 0)

#define mutex_trylock(m) (!__mutex_trylock(m))

#define thread_atfork(prepare, parent, child) do {} while(0)

#define thread_atfork_static(prepare, parent, child) \

 text_set_element(_hurd_fork_prepare_hook, prepare); \

 text_set_element(_hurd_fork_parent_hook, parent); \

 text_set_element(_hurd_fork_child_hook, child);

/* No we're *not* using pthreads.  */

#define __pthread_initialize ((void (*)(void))0)

#else

#define NO_THREADS

#endif /* MUTEX_INITIALIZER && PTHREAD_MUTEX_INITIALIZER */

#ifndef NO_THREADS

/* thread specific data for glibc */

#include <libc-tsd.h>

typedef int tsd_key_t[1];       /* no key data structure, libc magic does it */

__libc_tsd_define (, MALLOC)    /* declaration/common definition */

#define tsd_key_create(key, destr)      ((void) (key))

#define tsd_setspecific(key, data)      __libc_tsd_set (MALLOC, (data))

#define tsd_getspecific(key, vptr)      ((vptr) = __libc_tsd_get (MALLOC))

#endif

#elif defined(USE_PTHREADS) /* Posix threads */

#include <pthread.h>

typedef pthread_t thread_id;

/* mutex */

typedef pthread_mutex_t mutex_t;

#define MUTEX_INITIALIZER          PTHREAD_MUTEX_INITIALIZER

#define mutex_init(m)              pthread_mutex_init(m, NULL)

#define mutex_lock(m)              pthread_mutex_lock(m)

#define mutex_trylock(m)           pthread_mutex_trylock(m)

#define mutex_unlock(m)            pthread_mutex_unlock(m)

/* thread specific data */

#if defined(__sgi) || defined(USE_TSD_DATA_HACK)

/* Hack for thread-specific data, e.g. on Irix 6.x.  We can't use

   pthread_setspecific because that function calls malloc() itself.

   The hack only works when pthread_t can be converted to an integral

   type. */

typedef void *tsd_key_t[256];

#define tsd_key_create(key, destr) do { \

  int i; \

  for(i=0; i<256; i++) (*key)[i] = 0; \

} while(0)

#define tsd_setspecific(key, data) \

 (key[(unsigned)pthread_self() % 256] = (data))

#define tsd_getspecific(key, vptr) \

 (vptr = key[(unsigned)pthread_self() % 256])

#else

typedef pthread_key_t tsd_key_t;

#define tsd_key_create(key, destr) pthread_key_create(key, destr)

#define tsd_setspecific(key, data) pthread_setspecific(key, data)

#define tsd_getspecific(key, vptr) (vptr = pthread_getspecific(key))

#endif

/* at fork */

#define thread_atfork(prepare, parent, child) \

                                   pthread_atfork(prepare, parent, child)

#elif USE_THR /* Solaris threads */

#include <thread.h>

typedef thread_t thread_id;

#define MUTEX_INITIALIZER          { 0 }

#define mutex_init(m)              mutex_init(m, USYNC_THREAD, NULL)

/*

 * Hack for thread-specific data on Solaris.  We can't use thr_setspecific

 * because that function calls malloc() itself.

 */

typedef void *tsd_key_t[256];

#define tsd_key_create(key, destr) do { \

  int i; \

  for(i=0; i<256; i++) (*key)[i] = 0; \

} while(0)

#define tsd_setspecific(key, data) (key[(unsigned)thr_self() % 256] = (data))

#define tsd_getspecific(key, vptr) (vptr = key[(unsigned)thr_self() % 256])

#define thread_atfork(prepare, parent, child) do {} while(0)

#elif USE_SPROC /* SGI sproc() threads */

#include <sys/wait.h>

#include <sys/types.h>

#include <sys/prctl.h>

#include <abi_mutex.h>

typedef int thread_id;

typedef abilock_t mutex_t;

#define MUTEX_INITIALIZER          { 0 }

#define mutex_init(m)              init_lock(m)

#define mutex_lock(m)              (spin_lock(m), 0)

#define mutex_trylock(m)           acquire_lock(m)

#define mutex_unlock(m)            release_lock(m)

typedef int tsd_key_t;

int tsd_key_next;

#define tsd_key_create(key, destr) ((*key) = tsd_key_next++)

#define tsd_setspecific(key, data) (((void **)(&PRDA->usr_prda))[key] = data)

#define tsd_getspecific(key, vptr) (vptr = ((void **)(&PRDA->usr_prda))[key])

#define thread_atfork(prepare, parent, child) do {} while(0)

#else /* no _LIBC or USE_... are defined */

#define NO_THREADS

#endif /* defined(_LIBC) */

#ifdef NO_THREADS /* No threads, provide dummy macros */

typedef int thread_id;

/* The mutex functions used to do absolutely nothing, i.e. lock,

   trylock and unlock would always just return 0.  However, even

   without any concurrently active threads, a mutex can be used

   legitimately as an `in use' flag.  To make the code that is

   protected by a mutex async-signal safe, these macros would have to

   be based on atomic test-and-set operations, for example. */

typedef int mutex_t;

#define MUTEX_INITIALIZER          0

#define mutex_init(m)              (*(m) = 0)

#define mutex_lock(m)              ((*(m) = 1), 0)

#define mutex_trylock(m)           (*(m) ? 1 : ((*(m) = 1), 0))

#define mutex_unlock(m)            (*(m) = 0)

typedef void *tsd_key_t;

#define tsd_key_create(key, destr) do {} while(0)

#define tsd_setspecific(key, data) ((key) = (data))

#define tsd_getspecific(key, vptr) (vptr = (key))

#define thread_atfork(prepare, parent, child) do {} while(0)

#endif /* defined(NO_THREADS) */

#endif /* !defined(_THREAD_M_H) */