NAME    [Toc]    [Back]

       pthread_mutexattr_setpshared  -  Sets  the  process-shared
       attribute of a mutex attributes object

SYNOPSIS    [Toc]    [Back]

       #include <pthread.h>

       int pthread_mutexattr_setpshared(
               pthread_mutexattr_t *attr,
               int pshared );

LIBRARY    [Toc]    [Back]

       DECthreads POSIX 1003.1c Library (libpthread.so)

PARAMETERS    [Toc]    [Back]

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

DESCRIPTION    [Toc]    [Back]

       This routine uses the value in pshared to set the processshared
 attribute in the mutex 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.

       Setting   the  process-shared  attribute  to  PTHREAD_PROCESS_PRIVATE
 permits  a  mutex  to  be  operated  upon  by
       threads created within the same process as the thread that
       initialized the mutex. If threads of  differing  processes
       attempt  to operate on such a mutex, the behavior is undefined.


       The default value of the  process-shared  attribute  of  a
       mutex attributes object is PTHREAD_PROCESS_PRIVATE.

       Setting   the  process-shared  attribute  to  PTHREAD_PROCESS_SHARED
 permits a mutex to be  operated  upon  by  any
       thread  that  has  access to the memory where the mutex is
       allocated, even if the mutex is allocated in  memory  that
       is shared by multiple processes.

RETURN VALUES    [Toc]    [Back]

       If  an  error  condition  occurs,  this routine returns an
       integer value  indicating  the  type  of  error.  Possible
       return  values are as follows: Successful completion.  The
       value specified by attr is not a  valid  mutex  attributes
       object,  or  the  new value specified for the attribute is
       outside the range of legal values for that attribute.

ERRORS    [Toc]    [Back]

       None

SEE ALSO    [Toc]    [Back]

       Functions: pthread_mutexattr_getpshared(3), pthread_mutexattr_init(3)

       Manuals: Guide to DECthreads and Programmer's Guide



                                  pthread_mutexattr_setpshared(3)