glibc/linuxthreads/sysdeps/pthread/bits/libc-lock.h

/* libc-internal interface for mutex locks.  LinuxThreads version.
   Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#ifndef _BITS_LIBC_LOCK_H
#define _BITS_LIBC_LOCK_H 1

#include <pthread.h>

/* Mutex type.  */
#ifdef _LIBC
typedef pthread_mutex_t __libc_lock_t;
typedef pthread_rwlock_t __libc_rwlock_t;
#else
typedef struct __libc_lock_opaque__ __libc_lock_t;
typedef struct __libc_rwlock_opaque__ __libc_rwlock_t;
#endif

/* Type for key to thread-specific data.  */
typedef pthread_key_t __libc_key_t;

/* Define a lock variable NAME with storage class CLASS.  The lock must be
   initialized with __libc_lock_init before it can be used (or define it
   with __libc_lock_define_initialized, below).  Use `extern' for CLASS to
   declare a lock defined in another module.  In public structure
   definitions you must use a pointer to the lock structure (i.e., NAME
   begins with a `*'), because its storage size will not be known outside
   of libc.  */
#define __libc_lock_define(CLASS,NAME) \
  CLASS __libc_lock_t NAME;
#define __libc_rwlock_define(CLASS,NAME) \
  CLASS __libc_rwlock_t NAME;

/* Define an initialized lock variable NAME with storage class CLASS.

   For the C library we take a deeper look at the initializer.  For this
   implementation all fields are initialized to zero.  Therefore we
   don't initialize the variable which allows putting it into the BSS
   section.  */
#define __libc_lock_define_initialized(CLASS,NAME) \
  CLASS __libc_lock_t NAME;
#define __libc_rwlock_define_initialized(CLASS,NAME) \
  CLASS __libc_rwlock_t NAME = PTHREAD_RWLOCK_INITIALIZER;

/* Define an initialized recursive lock variable NAME with storage
   class CLASS.  */
#define __libc_lock_define_initialized_recursive(CLASS,NAME) \
  CLASS __libc_lock_t NAME = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;

/* Initialize the named lock variable, leaving it in a consistent, unlocked
   state.  */
#define __libc_lock_init(NAME) \
  (__pthread_mutex_init != NULL ? __pthread_mutex_init (&(NAME), NULL) : 0);
#define __libc_rwlock_init(NAME) \
  (__pthread_rwlock_init != NULL ? __pthread_rwlock_init (&(NAME), NULL) : 0);

/* Same as last but this time we initialize a recursive mutex.  */
#define __libc_lock_init_recursive(NAME) \
  do {									      \
    if (__pthread_mutex_init != NULL)					      \
      {									      \
	pthread_mutexattr_t __attr;					      \
	__pthread_mutexattr_init (&__attr);				      \
	__pthread_mutexattr_settype (&__attr, PTHREAD_MUTEX_RECURSIVE_NP); \
	__pthread_mutex_init (&(NAME), &__attr);			      \
	__pthread_mutexattr_destroy (&__attr);				      \
      }									      \
  } while (0);

/* Finalize the named lock variable, which must be locked.  It cannot be
   used again until __libc_lock_init is called again on it.  This must be
   called on a lock variable before the containing storage is reused.  */
#define __libc_lock_fini(NAME) \
  (__pthread_mutex_destroy != NULL ? __pthread_mutex_destroy (&(NAME)) : 0);
#define __libc_rwlock_fini(NAME) \
  (__pthread_rwlock_destroy != NULL ? __pthread_rwlock_destroy (&(NAME)) : 0);

/* Finalize recursive named lock.  */
#define __libc_lock_fini_recursive(NAME) __libc_lock_fini (NAME)

/* Lock the named lock variable.  */
#define __libc_lock_lock(NAME) \
  (__pthread_mutex_lock != NULL ? __pthread_mutex_lock (&(NAME)) : 0);
#define __libc_rwlock_rdlock(NAME) \
  (__pthread_rwlock_rdlock != NULL ? __pthread_rwlock_rdlock (&(NAME)) : 0);
#define __libc_rwlock_wrlock(NAME) \
  (__pthread_rwlock_wrlock != NULL ? __pthread_rwlock_wrlock (&(NAME)) : 0);

/* Lock the recursive named lock variable.  */
#define __libc_lock_lock_recursive(NAME) __libc_lock_lock (NAME)

/* Try to lock the named lock variable.  */
#define __libc_lock_trylock(NAME) \
  (__pthread_mutex_trylock != NULL ? __pthread_mutex_trylock (&(NAME)) : 0)
#define __libc_rwlock_tryrdlock(NAME) \
  (__pthread_rwlock_tryrdlock != NULL \
   ? __pthread_rwlock_tryrdlock (&(NAME)) : 0)
#define __libc_rwlock_trywrlock(NAME) \
  (__pthread_rwlock_trywrlock != NULL \
   ? __pthread_rwlock_trywrlock (&(NAME)) : 0)

/* Try to lock the recursive named lock variable.  */
#define __libc_lock_trylock_recursive(NAME) __libc_lock_trylock (NAME)

/* Unlock the named lock variable.  */
#define __libc_lock_unlock(NAME) \
  (__pthread_mutex_unlock != NULL ? __pthread_mutex_unlock (&(NAME)) : 0);
#define __libc_rwlock_unlock(NAME) \
  (__pthread_rwlock_unlock != NULL ? __pthread_rwlock_unlock (&(NAME)) : 0);

/* Unlock the recursive named lock variable.  */
#define __libc_lock_unlock_recursive(NAME) __libc_lock_unlock (NAME)


/* Define once control variable.  */
#if PTHREAD_ONCE_INIT == 0
/* Special case for static variables where we can avoid the initialization
   if it is zero.  */
# define __libc_once_define(CLASS, NAME) \
  CLASS pthread_once_t NAME
#else
# define __libc_once_define(CLASS, NAME) \
  CLASS pthread_once_t NAME = PTHREAD_ONCE_INIT
#endif

/* Call handler iff the first call.  */
#define __libc_once(ONCE_CONTROL, INIT_FUNCTION) \
  do {									      \
    if (__pthread_once != NULL)						      \
      __pthread_once (&(ONCE_CONTROL), (INIT_FUNCTION));		      \
    else if ((ONCE_CONTROL) == 0) {					      \
      INIT_FUNCTION ();							      \
      (ONCE_CONTROL) = 1;						      \
    }									      \
  } while (0)


/* Start critical region with cleanup.  */
#define __libc_cleanup_region_start(FCT, ARG) \
  { struct _pthread_cleanup_buffer _buffer;				      \
    int _avail = _pthread_cleanup_push_defer != NULL;			      \
    if (_avail) {							      \
      _pthread_cleanup_push_defer (&_buffer, (FCT), (ARG));		      \
    }

/* End critical region with cleanup.  */
#define __libc_cleanup_region_end(DOIT) \
    if (_avail) {							      \
      _pthread_cleanup_pop_restore (&_buffer, (DOIT));			      \
    }									      \
  }

/* Sometimes we have to exit the block in the middle.  */
#define __libc_cleanup_end(DOIT) \
    if (_avail) {							      \
      _pthread_cleanup_pop_restore (&_buffer, (DOIT));			      \
    }

/* Create thread-specific key.  */
#define __libc_key_create(KEY, DESTRUCTOR) \
  (__pthread_key_create != NULL ? __pthread_key_create (KEY, DESTRUCTOR) : 1)

/* Get thread-specific data.  */
#define __libc_getspecific(KEY) \
  (__pthread_getspecific != NULL ? __pthread_getspecific (KEY) : NULL)

/* Set thread-specific data.  */
#define __libc_setspecific(KEY, VALUE) \
  (__pthread_setspecific != NULL ? __pthread_setspecific (KEY, VALUE) : 0)


/* Register handlers to execute before and after `fork'.  */
#define __libc_atfork(PREPARE, PARENT, CHILD) \
  (__pthread_atfork != NULL ? __pthread_atfork (PREPARE, PARENT, CHILD) : 0)

/* Functions that are used by this file and are internal to the GNU C
   library.  */

extern int __pthread_mutex_init (pthread_mutex_t *__mutex,
				 __const pthread_mutexattr_t *__mutex_attr);

extern int __pthread_mutex_destroy (pthread_mutex_t *__mutex);

extern int __pthread_mutex_trylock (pthread_mutex_t *__mutex);

extern int __pthread_mutex_lock (pthread_mutex_t *__mutex);

extern int __pthread_mutex_unlock (pthread_mutex_t *__mutex);

extern int __pthread_mutexattr_init (pthread_mutexattr_t *__attr);

extern int __pthread_mutexattr_destroy (pthread_mutexattr_t *__attr);

extern int __pthread_mutexattr_settype (pthread_mutexattr_t *__attr,
					int __kind);

extern int __pthread_rwlock_init (pthread_rwlock_t *__rwlock,
				  __const pthread_rwlockattr_t *__attr);

extern int __pthread_rwlock_destroy (pthread_rwlock_t *__rwlock);

extern int __pthread_rwlock_rdlock (pthread_rwlock_t *__rwlock);

extern int __pthread_rwlock_tryrdlock (pthread_rwlock_t *__rwlock);

extern int __pthread_rwlock_wrlock (pthread_rwlock_t *__rwlock);

extern int __pthread_rwlock_trywrlock (pthread_rwlock_t *__rwlock);

extern int __pthread_rwlock_unlock (pthread_rwlock_t *__rwlock);

extern int __pthread_key_create (pthread_key_t *__key,
				 void (*__destr_function) (void *));

extern int __pthread_setspecific (pthread_key_t __key,
				  __const void *__pointer);

extern void *__pthread_getspecific (pthread_key_t __key);

extern int __pthread_once (pthread_once_t *__once_control,
			   void (*__init_routine) (void));

extern int __pthread_atfork (void (*__prepare) (void),
			     void (*__parent) (void),
			     void (*__child) (void));



/* Make the pthread functions weak so that we can elide them from
   single-threaded processes.  */
#ifndef __NO_WEAK_PTHREAD_ALIASES
# ifdef weak_extern
weak_extern (__pthread_mutex_init)
weak_extern (__pthread_mutex_destroy)
weak_extern (__pthread_mutex_lock)
weak_extern (__pthread_mutex_trylock)
weak_extern (__pthread_mutex_unlock)
weak_extern (__pthread_mutexattr_init)
weak_extern (__pthread_mutexattr_destroy)
weak_extern (__pthread_mutexattr_settype)
weak_extern (__pthread_rwlock_init)
weak_extern (__pthread_rwlock_destroy)
weak_extern (__pthread_rwlock_rdlock)
weak_extern (__pthread_rwlock_tryrdlock)
weak_extern (__pthread_rwlock_wrlock)
weak_extern (__pthread_rwlock_trywrlock)
weak_extern (__pthread_rwlock_unlock)
weak_extern (__pthread_key_create)
weak_extern (__pthread_setspecific)
weak_extern (__pthread_getspecific)
weak_extern (__pthread_once)
weak_extern (__pthread_initialize)
weak_extern (__pthread_atfork)
weak_extern (_pthread_cleanup_push_defer)
weak_extern (_pthread_cleanup_pop_restore)
# else
#  pragma weak __pthread_mutex_init
#  pragma weak __pthread_mutex_destroy
#  pragma weak __pthread_mutex_lock
#  pragma weak __pthread_mutex_trylock
#  pragma weak __pthread_mutex_unlock
#  pragma weak __pthread_mutexattr_init
#  pragma weak __pthread_mutexattr_destroy
#  pragma weak __pthread_mutexattr_settype
#  pragna weak __pthread_rwlock_destroy
#  pragma weak __pthread_rwlock_rdlock
#  pragma weak __pthread_rwlock_tryrdlock
#  pragma weak __pthread_rwlock_wrlock
#  pragma weak __pthread_rwlock_trywrlock
#  pragma weak __pthread_rwlock_unlock
#  pragma weak __pthread_key_create
#  pragma weak __pthread_setspecific
#  pragma weak __pthread_getspecific
#  pragma weak __pthread_once
#  pragma weak __pthread_initialize
#  pragma weak __pthread_atfork
#  pragma weak _pthread_cleanup_push_defer
#  pragma weak _pthread_cleanup_pop_restore
# endif
#endif

/* We need portable names for some functions.  E.g., when they are
   used as argument to __libc_cleanup_region_start.  */
#define __libc_mutex_unlock __pthread_mutex_unlock

#endif	/* bits/libc-lock.h */