pthread_mutexattr_setpshared - Sets the process-shared
attribute of a mutex attributes object
int pshared );
DECthreads POSIX 1003.1c Library (libpthread.so)
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.
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.
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.
Functions: pthread_mutexattr_getpshared(3), pthread_mutexattr_init(3)
Manuals: Guide to DECthreads and Programmer's Guide
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