pthread_mutexattr_getpshared(3)pthread_mutexattr_getpshared(3)NAMEpthread_mutexattr_getpshared - Obtains the process-shared attribute of
a mutex attributes object
SYNOPSIS
#include <pthread.h>
int pthread_mutexattr_getpshared(
const pthread_mutexattr_t *attr,
int *pshared );
LIBRARY
DECthreads POSIX 1003.1c Library (libpthread.so)
PARAMETERS
Address of the mutex attributes object whose process-shared attribute
is to be obtained. Location to store the value of the process-shared
attribute of attr.
DESCRIPTION
This routine obtains the value of the process-shared attribute in the
mutex attributes object referenced by attr and stores it at the loca‐
tion pshared. The object referenced by attr must be initialized before
this routine is called.
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 pro‐
cesses 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 programs.
RETURN VALUES
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
attributes object.
ERRORS
None
SEE ALSO
Functions: pthread_mutexattr_setpshared(3), pthread_mutexattr_init(3)
Manuals: Guide to DECthreads and Programmer's Guide
pthread_mutexattr_getpshared(3)