MsgQueueSend()
QNX SDP8.0C Library ReferenceAPIDeveloper
Send a message on an open queue
Note:
Don't use the MsgQueueSend() kernel call directly;
instead, use mq_send().
Synopsis:
#include <sys/neutrino.h>
int MsgQueueSend( int fd,
char const* msg,
size_t msglen,
unsigned priority );
Arguments:
- fd
- A coid that identifies the open queue to send a message on.
- msg
- A pointer to a buffer containing the message to send.
- msglen
- The length of the buffer. This must not be larger than the queue's mq_msgsize.
- priority
- The mq priority at which to send the message.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
The MsgQueueSend() kernel call enqueues a message to the message queue specified by fd. If the queue is full and O_NONBLOCK was not specified, the calling thread enters the STATE_MQ_SEND state, indicating it is blocked while waiting for space to become available on the queue. If O_NONBLOCK was specified, the call does not block and instead returns EAGAIN.
Returns:
- 0
- Success.
- -1
- An error occurred (errno is set).
Errors:
- EAGAIN
- The queue is full and O_NONBLOCK was set.
- EBADF
- One of the following errors occured:
- The fd is not associated with a message queue.
- The fd is not open for writing.
- EINTR
- The operation was interrupted by a signal.
- EINVAL
- The priority is out of range.
- EMSGSIZE
- The message size is too big for the queue.
- ETIMEDOUT
- The queue is full and a timeout expired.
Classification:
| Safety: | |
|---|---|
| Cancellation point | No |
| Signal handler | Yes |
| Thread | Yes |
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