pthread_mutexattr_setpshared(3)pthread_mutexattr_setpshared(3)NAMEpthread_mutexattr_setpshared - Sets the process-shared attribute of a
mutex attributes object
SYNOPSIS
#include <pthread.h>
int pthread_mutexattr_setpshared(
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 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
This routine uses the value in pshared to set the process-shared
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 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 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:
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
None
SEE ALSO
Functions: pthread_mutexattr_getpshared(3), pthread_mutexattr_init(3)
Manuals: Guide to DECthreads and Programmer's Guide
pthread_mutexattr_setpshared(3)