rt/mqueue.h

   1 /* Copyright (C) 2004-2016 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _MQUEUE_H
  19 #define _MQUEUE_H       1
  20
  21 #include <features.h>
  22 #include <sys/types.h>
  23 #include <fcntl.h>
  24 #define __need_sigevent_t
  25 #include <bits/siginfo.h>
  26 #include <bits/types/struct_timespec.h>
  27 /* Get the definition of mqd_t and struct mq_attr.  */
  28 #include <bits/mqueue.h>
  29
  30 __BEGIN_DECLS
  31
  32 /* Establish connection between a process and a message queue NAME and
  33    return message queue descriptor or (mqd_t) -1 on error.  OFLAG determines
  34    the type of access used.  If O_CREAT is on OFLAG, the third argument is
  35    taken as a `mode_t', the mode of the created message queue, and the fourth
  36    argument is taken as `struct mq_attr *', pointer to message queue
  37    attributes.  If the fourth argument is NULL, default attributes are
  38    used.  */
  39 extern mqd_t mq_open (const char *__name, int __oflag, ...)
  40   __THROW __nonnull ((1));
  41
  42 /* Removes the association between message queue descriptor MQDES and its
  43    message queue.  */
  44 extern int mq_close (mqd_t __mqdes) __THROW;
  45
  46 /* Query status and attributes of message queue MQDES.  */
  47 extern int mq_getattr (mqd_t __mqdes, struct mq_attr *__mqstat)
  48   __THROW __nonnull ((2));
  49
  50 /* Set attributes associated with message queue MQDES and if OMQSTAT is
  51    not NULL also query its old attributes.  */
  52 extern int mq_setattr (mqd_t __mqdes,
  53                        const struct mq_attr *__restrict __mqstat,
  54                        struct mq_attr *__restrict __omqstat)
  55   __THROW __nonnull ((2));
  56
  57 /* Remove message queue named NAME.  */
  58 extern int mq_unlink (const char *__name) __THROW __nonnull ((1));
  59
  60 /* Register notification issued upon message arrival to an empty
  61    message queue MQDES.  */
  62 extern int mq_notify (mqd_t __mqdes, const struct sigevent *__notification)
  63      __THROW;
  64
  65 /* Receive the oldest from highest priority messages in message queue
  66    MQDES.  */
  67 extern ssize_t mq_receive (mqd_t __mqdes, char *__msg_ptr, size_t __msg_len,
  68                            unsigned int *__msg_prio) __nonnull ((2));
  69
  70 /* Add message pointed by MSG_PTR to message queue MQDES.  */
  71 extern int mq_send (mqd_t __mqdes, const char *__msg_ptr, size_t __msg_len,
  72                     unsigned int __msg_prio) __nonnull ((2));
  73
  74 #ifdef __USE_XOPEN2K
  75 /* Receive the oldest from highest priority messages in message queue
  76    MQDES, stop waiting if ABS_TIMEOUT expires.  */
  77 extern ssize_t mq_timedreceive (mqd_t __mqdes, char *__restrict __msg_ptr,
  78                                 size_t __msg_len,
  79                                 unsigned int *__restrict __msg_prio,
  80                                 const struct timespec *__restrict __abs_timeout)
  81   __nonnull ((2, 5));
  82
  83 /* Add message pointed by MSG_PTR to message queue MQDES, stop blocking
  84    on full message queue if ABS_TIMEOUT expires.  */
  85 extern int mq_timedsend (mqd_t __mqdes, const char *__msg_ptr,
  86                          size_t __msg_len, unsigned int __msg_prio,
  87                          const struct timespec *__abs_timeout)
  88   __nonnull ((2, 5));
  89 #endif
  90
  91 /* Define some inlines helping to catch common problems.  */
  92 #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function \
  93     && defined __va_arg_pack_len
  94 # include <bits/mqueue2.h>
  95 #endif
  96
  97 __END_DECLS
  98
  99 #endif /* mqueue.h */