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Manage message queues and named semaphores (QNX Neutrino)

Note: You must be root to start this manager.


mqueue &




The mqueue manager implements POSIX 1003.1b message queues and named semaphores. When a queue is created, it appears in the pathname space under /dev/mqueue. Named semaphores appear in the pathname space under /dev/sem.

The POSIX message queue manager is a resource manager communicating via messages with its clients. It may be accessed both locally or remotely allowing for network-wide message queues. The following special client functions communicate with mqueue:

Function Description
mq_open() Open or create a queue
mq_close() Close a queue
mq_unlink() Remove a message queue
mq_getattr() Get attributes on a queue
mq_setattr() Set attributes on a queue
mq_notify() Request notification when a message arrives
mq_send() Send a message
mq_receive() Receive a message

The following client functions communicate with mqueue for named semaphore operations:

Function Description
sem_close() Close a named semaphore
sem_getvalue() Get the value of a semaphore
sem_open() Create/access a named semaphore
sem_post() Increment a semaphore
sem_trywait() Wait on a semaphore, but don't block
sem_unlink() Destroy a named semaphore
sem_wait() Wait on a semaphore

For more information about these functions, see the QNX Neutrino Library Reference.

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