pthread_rwlockattr_getpshared(3) [freebsd man page]

PTHREAD_RWLOCKATTR_GETPSHARED(3)			   BSD Library Functions Manual 			  PTHREAD_RWLOCKATTR_GETPSHARED(3)

NAME

     pthread_rwlockattr_getpshared -- get the process shared attribute

LIBRARY

     POSIX Threads Library (libpthread, -lpthread)

SYNOPSIS

     #include <pthread.h>

     int
     pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *attr, int *pshared);

DESCRIPTION

     The pthread_rwlockattr_getpshared() function is used to get the process shared setting of a read/write lock attribute object.  The setting is
     returned via pshared, and may be one of two values:

     PTHREAD_PROCESS_SHARED   Any thread of any process that has access to the memory where the read/write lock resides can manipulate the lock.

     PTHREAD_PROCESS_PRIVATE  Only threads created within the same process as the thread that initialized the read/write lock can manipulate the
			      lock.  This is the default value.

RETURN VALUES

     If successful, the pthread_rwlockattr_getpshared() function will return zero.  Otherwise an error number will be returned to indicate the
     error.

ERRORS

     The pthread_rwlockattr_getpshared() function may fail if:

     [EINVAL]		The value specified by attr is invalid.

SEE ALSO

     pthread_rwlock_init(3), pthread_rwlockattr_init(3), pthread_rwlockattr_setpshared(3)

STANDARDS

     The pthread_rwlockattr_getpshared() function is expected to conform to Version 2 of the Single UNIX Specification (``SUSv2'').

HISTORY

     The pthread_rwlockattr_getpshared() function first appeared in FreeBSD 3.0.

BSD
								  March 22, 1999							       BSD

pthread_rwlockattr_getpshared(3C)										 pthread_rwlockattr_getpshared(3C)

NAME

       pthread_rwlockattr_getpshared, pthread_rwlockattr_setpshared - get or set process-shared attribute of read-write lock attributes object

SYNOPSIS

       cc -mt [ flag... ] file... -lpthread [ library... ]
       #include <pthread.h>

       int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *restrict attr, int *restrict pshared);

       int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr, int pshared);

       The  process-shared  attribute  is  set	to   PTHREAD_PROCESS_SHARED to permit a read-write lock to be operated upon by any thread that has
       access to the memory where the read-write lock is allocated,  even if the read-write lock is allocated in memory that is shared by multiple
       processes.  If  the process-shared attribute is	PTHREAD_PROCESS_PRIVATE, the read-write lock will only be operated upon by threads created
       within the same process as the thread that initialised the read-write lock; if threads of differing processes attempt to operate on such  a
       read-write lock, the behaviour is undefined. The default value of the process-shared attribute is  PTHREAD_PROCESS_PRIVATE.

       The  pthread_rwlockattr_getpshared() function obtains the value of the process-shared attribute from the initialised attributes object ref-
       erenced by attr. The  pthread_rwlockattr_setpshared() function is used to set the process-shared attribute  in  an  initialised	attributes
       object referenced by attr.

       If successful, the  pthread_rwlockattr_setpshared() function returns  0. Otherwise, an error number is returned to indicate the error.

       Upon  successful  completion,  the  pthread_rwlockattr_getpshared() returns  0 and stores the value of the process-shared attribute of attr
       into the object referenced by the pshared parameter. Otherwise an error number is returned to indicate the error.

       The pthread_rwlockattr_getpshared() and pthread_rwlockattr_setpshared() functions will fail if:

       EINVAL	       The value specified by attr  or pshared is invalid.

       See  attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

       pthread_rwlock_init(3C),  pthread_rwlock_rdlock(3C),  pthread_rwlock_unlock(3C),  pthread_rwlock_wrlock(3C),   pthread_rwlockattr_init(3C),
       attributes(5), standards(5)

								    23 Mar 2005 				 pthread_rwlockattr_getpshared(3C)