http://blog.csdn.net/yangzhongxuan/article/details/7397139

/* Copyright (C) 2002,2003,2004,2005,2006,2007 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

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. */

#ifndef _BITS_PTHREADTYPES_H
#define _BITS_PTHREADTYPES_H 1

#include <bits/wordsize.h>

#if __WORDSIZE == 64
# define __SIZEOF_PTHREAD_ATTR_T 56
# define __SIZEOF_PTHREAD_MUTEX_T 40
# define __SIZEOF_PTHREAD_MUTEXATTR_T 4
# define __SIZEOF_PTHREAD_COND_T 48
# define __SIZEOF_PTHREAD_CONDATTR_T 4
# define __SIZEOF_PTHREAD_RWLOCK_T 56
# define __SIZEOF_PTHREAD_RWLOCKATTR_T 8
# define __SIZEOF_PTHREAD_BARRIER_T 32
# define __SIZEOF_PTHREAD_BARRIERATTR_T 4
#else
# define __SIZEOF_PTHREAD_ATTR_T 36
# define __SIZEOF_PTHREAD_MUTEX_T 24
# define __SIZEOF_PTHREAD_MUTEXATTR_T 4
# define __SIZEOF_PTHREAD_COND_T 48
# define __SIZEOF_PTHREAD_CONDATTR_T 4
# define __SIZEOF_PTHREAD_RWLOCK_T 32
# define __SIZEOF_PTHREAD_RWLOCKATTR_T 8
# define __SIZEOF_PTHREAD_BARRIER_T 20
# define __SIZEOF_PTHREAD_BARRIERATTR_T 4
#endif

/* Thread identifiers. The structure of the attribute type is not
exposed on purpose. */
typedef unsigned long int pthread_t;

typedef union
{
char __size[__SIZEOF_PTHREAD_ATTR_T];
long int __align;
} pthread_attr_t;

#if __WORDSIZE == 64
typedef struct __pthread_internal_list
{
struct __pthread_internal_list *__prev;
struct __pthread_internal_list *__next;
} __pthread_list_t;
#else
typedef struct __pthread_internal_slist
{
struct __pthread_internal_slist *__next;
} __pthread_slist_t;
#endif

/* Data structures for mutex handling. The structure of the attribute
type is not exposed on purpose. */
typedef union
{
struct __pthread_mutex_s
{
int __lock;
unsigned int __count;
int __owner;
#if __WORDSIZE == 64
unsigned int __nusers;
#endif
/* KIND must stay at this position in the structure to maintain
binary compatibility. */
int __kind;
#if __WORDSIZE == 64
int __spins;
__pthread_list_t __list;
# define __PTHREAD_MUTEX_HAVE_PREV 1
#else
unsigned int __nusers;
__extension__ union
{
int __spins;
__pthread_slist_t __list;
};
#endif
} __data;
char __size[__SIZEOF_PTHREAD_MUTEX_T];
long int __align;
} pthread_mutex_t;

typedef union
{
char __size[__SIZEOF_PTHREAD_MUTEXATTR_T];
int __align;
} pthread_mutexattr_t;

/* Data structure for conditional variable handling. The structure of
the attribute type is not exposed on purpose. */
typedef union
{
struct
{
int __lock;
unsigned int __futex;
__extension__ unsigned long long int __total_seq;
__extension__ unsigned long long int __wakeup_seq;
__extension__ unsigned long long int __woken_seq;
void *__mutex;
unsigned int __nwaiters;
unsigned int __broadcast_seq;
} __data;
char __size[__SIZEOF_PTHREAD_COND_T];
__extension__ long long int __align;
} pthread_cond_t;

typedef union
{
char __size[__SIZEOF_PTHREAD_CONDATTR_T];
int __align;
} pthread_condattr_t;

/* Keys for thread-specific data */
typedef unsigned int pthread_key_t;

/* Once-only execution */
typedef int pthread_once_t;

#if defined __USE_UNIX98 || defined __USE_XOPEN2K
/* Data structure for read-write lock variable handling. The
structure of the attribute type is not exposed on purpose. */
typedef union
{
# if __WORDSIZE == 64
struct
{
int __lock;
unsigned int __nr_readers;
unsigned int __readers_wakeup;
unsigned int __writer_wakeup;
unsigned int __nr_readers_queued;
unsigned int __nr_writers_queued;
int __writer;
int __shared;
unsigned long int __pad1;
unsigned long int __pad2;
/* FLAGS must stay at this position in the structure to maintain
binary compatibility. */
unsigned int __flags;
} __data;
# else
struct
{
int __lock;
unsigned int __nr_readers;
unsigned int __readers_wakeup;
unsigned int __writer_wakeup;
unsigned int __nr_readers_queued;
unsigned int __nr_writers_queued;
/* FLAGS must stay at this position in the structure to maintain
binary compatibility. */
unsigned char __flags;
unsigned char __shared;
unsigned char __pad1;
unsigned char __pad2;
int __writer;
} __data;
# endif
char __size[__SIZEOF_PTHREAD_RWLOCK_T];
long int __align;
} pthread_rwlock_t;

typedef union
{
char __size[__SIZEOF_PTHREAD_RWLOCKATTR_T];
long int __align;
} pthread_rwlockattr_t;
#endif

#ifdef __USE_XOPEN2K
/* POSIX spinlock data type. */
typedef volatile int pthread_spinlock_t;

/* POSIX barriers data type. The structure of the type is
deliberately not exposed. */
typedef union
{
char __size[__SIZEOF_PTHREAD_BARRIER_T];
long int __align;
} pthread_barrier_t;

typedef union
{
char __size[__SIZEOF_PTHREAD_BARRIERATTR_T];
int __align;
} pthread_barrierattr_t;
#endif

#if __WORDSIZE == 32
/* Extra attributes for the cleanup functions. */
# define __cleanup_fct_attribute __attribute__ ((__regparm__ (1)))
#endif

#endif /* bits/pthreadtypes.h */

pthread 的几个结构体