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pthread_rwlockattr_setpshared(3)
NAME
  pthread_rwlockattr_setpshared - Sets the process-shared attribute in a
  read-write lock attributes object.

LIBRARY
  DECthreads POSIX 1003.1c Library (libpthread.so)

SYNOPSIS
  #include <pthread.h>

  int	pthread_rwlockattr_setpshared(
			pthread_rwlockattr_t	   *attr,
			int			   pshared);

PARAMETERS
  attr	    Address of the read-write lock attributes object whose process-
	    shared attribute is to be set.

  pshared   Value to set in the process-shared attribute of attr. Must be the
	    value PTHREAD_PROCESS_SHARED, to permit access to the read-write
	    lock by any thread in any process that can access the memory
	    where the lock object is allocated, or PTHREAD_PROCESS_PRIVATE,
	    to permit access to the read-write lock only by threads in the
	    same process as the thread that initialized the read-write lock
	    object.

DESCRIPTION
  This routine uses the value in pshared to set the process-shared attribute
  in the read-write lock attributes object referenced by attr. The object
  referenced by attr must be initialized before this routine is called. The
  value of pshared must be either PTHREAD_PROCESS_SHARED or
  PTHREAD_PROCESS_PRIVATE, as defined in the pthread.h include file.

  If the process-shared attribute is set to PTHREAD_PROCESS_PRIVATE, the
  read-write lock object can only be operated upon by threads created within
  the same process as the thread that initialized the read-write lock object.
  If threads of differing processes attempt to operate on such a read-write
  lock object, the behavior is undefined.

  The default value of the process-shared attribute of a read-write lock
  attributes object is PTHREAD_PROCESS_PRIVATE.

  If the process-shared attribute of a read-write lock attributes object is
  set to PTHREAD_PROCESS_SHARED, the read-write lock object can be operated
  upon by any thread that has access to the memory where that object is
  allocated, even if that object is allocated in memory that is shared by
  multiple processes.

RETURN VALUES
  If an error condition occurs, this routine returns an integer value
  indicating the type of error.	 Possible return values are as follows:

  0	    Successful completion.

  [EINVAL]  The value specified by attr is not a valid attributes object, or
	    the value pshared is outside the range of legal values for that
	    attribute.

ERRORS
  None

RELATED INFORMATION
  Functions: pthread_rwlockattr_getpshared(3), pthread_rwlockattr_init(3)

  Manuals: Guide to DECthreads and Programmer's Guide

Index for Section 3

Alphabetical listing for P

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