![[Previous]](../prev.gif) |
![[Contents]](../contents.gif) |
![[Index]](../keyword_index.gif) |
![[Next]](../next.gif) |
|
|
|
|
Manage message queues and named semaphores (QNX Neutrino)
 |
You must be root to start this manager. |
mqueue &
None.
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.
|
|
|
|