This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior), or
the interface may not be implemented on Linux.
The <mqueue.h> header shall define the mqd_t type, which is used for
message queue descriptors. This is not an array type.
The <mqueue.h> header shall define the pthread_attr_t, size_t, and
ssize_t types as described in <sys/types.h>.
The <mqueue.h> header shall define the struct timespec structure as
described in <time.h>.
The tag sigevent shall be declared as naming an incomplete structure
type, the contents of which are described in the <signal.h> header.
The <mqueue.h> header shall define 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. An
mq_attr structure shall have at least the following fields:
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.
The following shall be declared as functions and may also be defined
as macros. Function prototypes shall be provided.
int mq_close(mqd_t);int mq_getattr(mqd_t, struct mq_attr *);int mq_notify(mqd_t, const struct sigevent *);mqd_t mq_open(const char *, int, ...);ssize_t mq_receive(mqd_t, char *, size_t, unsigned *);int mq_send(mqd_t, const char *, size_t, unsigned);int mq_setattr(mqd_t, const struct mq_attr *restrict,struct mq_attr *restrict);ssize_t mq_timedreceive(mqd_t, char *restrict, size_t,unsigned *restrict, const struct timespec *restrict);int mq_timedsend(mqd_t, const char *, size_t, unsigned,const struct timespec *);int mq_unlink(const char *);
Inclusion of the <mqueue.h> header may make visible symbols defined
in the headers <fcntl.h>, <signal.h>, and <time.h>.
The following sections are informative.
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) In the event of any discrepancy between this version and
the original IEEE and The Open Group Standard, the original IEEE and
The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the
source files to man page format. To report such errors, see
IEEE/The Open Group 2013 mqueue.h(0P)