pthread_mutexattr_setprotocol()

Set a mutex's scheduling protocol

Synopsis:

#include <pthread.h>

int pthread_mutexattr_setprotocol( 
            pthread_mutexattr * attr,
            int protocol );

Library:

libc

Description:

The pthread_mutexattr_setprotocol() function sets the mutex attribute attr's scheduling protocol to protocol. The structure pointed to by attr must have been previously created with pthread_mutexattr_init().

The protocol attribute defines the protocol for using mutexes. Currently, protocol may be set to:

PTHREAD_PRIO_INHERIT

When a thread is blocking higher-priority threads by locking one or more mutexes with this attribute, the thread's priority is raised to that of the highest priority thread waiting on the PTHREAD_PRIO_INHERIT mutex.

A thread holding a PTHREAD_PRIO_INHERIT mutex won't be moved to the tail of the scheduling queue if its original priority is changed (by a call to pthread_schedsetparam(), for example). This remains true if the thread unlocks the PTHREAD_PRIO_INHERIT mutex.

The POSIX protocol of PTHREAD_PRIO_PROTECT isn't currently supported.

Returns:

EOK

Success.

ENOSYS

PTHREAD_PRIO_PROTECT isn't currently supported.

ENOTSUP

The protocol argument is an unsupported or an invalid value.

Classification:

POSIX 1003.1 (Threads)

See also:

pthread_mutexattr_getprotocol(), pthread_mutexattr_getrecursive()