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#include <bits/wordsize.h>

#if __WORDSIZE == 64
# define __SIZEOF_SEM_T 32
#else
# define __SIZEOF_SEM_T 16
#endif


/* Value returned if `sem_open' failed.  */
#define SEM_FAILED      ((sem_t *) 0)


typedef union
{
  char __size[__SIZEOF_SEM_T];
  long int __align;
} sem_t;

/* Initialize semaphore object SEM to VALUE.  If PSHARED then share it
   with other processes.  */
extern int sem_init (sem_t *__sem, int __pshared, unsigned int __value)
     __THROW;

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ENOSYS : pshared ·ÇÁ㣬µ«ÏµÍ³»¹Ã»ÓÐÖ§³Ö½ø³Ì¹²ÏíµÄÐźÅÁ¿

/* Create a new thread, starting with execution of START-ROUTINE
   getting passed ARG.  Creation attributed come from ATTR.  The new
   handle is stored in *NEWTHREAD.  */
extern int pthread_create (pthread_t *__restrict __newthread,
                           __const pthread_attr_t *__restrict __attr,
                           void *(*__start_routine) (void *),
                           void *__restrict __arg) __THROW __nonnull ((1, 3));

/* Make calling thread wait for termination of the thread TH.  The
   exit status of the thread is stored in *THREAD_RETURN, if THREAD_RETURN
   is not NULL.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int pthread_join (pthread_t __th, void **__thread_return);

/* Wait for SEM being posted.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int sem_wait (sem_t *__sem);

/* Post SEM.  */
extern int sem_post (sem_t *__sem) __THROW;

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