HP-UX Reference (11i v3 07/02) - 2 System Calls (vol 5)

mq_close(2) mq_close(2)

NAME

mq_close - close a message queue descriptor

SYNOPSIS

#include <sys/mqueue.h>

int mq_close(mqd_t mqdes);

DESCRIPTION

The mq_close() system call removes the association between the message queue descriptor, mqdes, and

a message queue. Use of this message queue descriptor by the process, after a successful return from this

mq_close() , and until this descriptor is returned by a subsequent

mq_open(), will result in the failure

of message queue system calls, with

errno set to [EBADF].

If the process has a registered notiﬁcation request with the message queue associated with this mqdes, the

registration is canceled and the queue becomes available for another process to register a notiﬁcation

request.

If the message queue has been unlinked and mqdes is the only existing open descriptor for the queue, the

queue is destroyed.

To use this function, link in the realtime library by specifying

-lrt on the compiler or linker command

line.

RETURN VALUE

mq_close() returns the following values:

0 Successful completion.

-1 Failure. errno is set to indicate the error.

ERRORS

If mq_close() fails, errno is set to one of the following values:

[EBADF] mqdes is not a valid message queue descriptor.

[ENOSYS] mq_close() is not supported by the implementation.