NAME

mqueue.h, mqueue - message queues

SYNOPSIS

#include <mqueue.h>

DESCRIPTION

The <mqueue.h> header defines the mqd_t type, which is used for message queue descriptors. This will not be an array type. A message queue descriptor may be implemented using a file descriptor, in which case applications can open up to at least OPEN_MAX file and message queues.

The <mqueue.h> header defines the sigevent structure (as described in <signal.h>, see signal.h(3HEAD)) and the mq_attr structure, which is used in getting and setting the attributes of a message queue. Attributes are initially set when the message queue is created. A mq_attr structure has the following members:

long    mq_flags       message queue flags
long    mq_maxmsg      maximum number of messages
long    mq_msgsize     maximum message size
long    mq_curmsgs     number of messages currently queued

Inclusion of the <mqueue.h> header may make visible symbols defined in the headers <fcntl.h>, <signal.h>, <sys/types.h>, and <time.h>.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:

SEE ALSO

fcntl.h(3HEAD), signal.h(3HEAD), time.h(3HEAD), types.h(3HEAD), attributes(7), standards(7)