/* * mqueue.h - definitions and function prototypes for POSIX mqueue support. */ #ifndef _MQUEUE_H #define _MQUEUE_H #include <features.h> #include <sys/types.h> #include <fcntl.h> #define __need_sigevent_t #include <bits/siginfo.h> #define __need_timespec #include <time.h> typedef int mqd_t; struct mq_attr { long int mq_flags; /* Message queue flags */ long int mq_maxmsg; /* Maximum number of messages */ long int mq_msgsize; /* Maximum message size */ long int mq_curmsgs; /* Number of messages currently queued */ long int __pad[4]; }; __BEGIN_DECLS /* * Establish connection between a process and a message queue __name and * return message queue descriptor or (mqd_t) -1 on error. __oflag determines * the type of access used. If O_CREAT is on __oflag, the third argument is * taken as a `mode_t', the mode of the created message queue, and the fourth * argument is taken as `struct mq_attr *', pointer to message queue * attributes. If the fourth argument is NULL, default attributes are used. */ extern mqd_t mq_open(const char *__name, int __oflag, ...) __THROW; /* * Remove the association between message queue descriptor __mqdes and its * message queue. */ extern int mq_close(mqd_t __mqdes) __THROW; /* Query status and attributes of message queue __mqdes */ extern int mq_getattr(mqd_t __mqdes, struct mq_attr *__mqstat) __THROW; /* * Set attributes associated with message queue __mqdes and if __omqstat is * not NULL also query its old attributes. */ extern int mq_setattr(mqd_t __mqdes, const struct mq_attr *__restrict __mqstat, struct mq_attr *__restrict __omqstat) __THROW; /* Remove message queue named __name */ extern int mq_unlink(const char *__name) __THROW; /* * Register notification upon message arrival to an empty message queue * __mqdes */ extern int mq_notify(mqd_t __mqdes, const struct sigevent *__notification) __THROW; /* * Receive the oldest from highest priority messages in message queue * __mqdes */ extern ssize_t mq_receive(mqd_t __mqdes, char *__msg_ptr, size_t __msg_len, unsigned int *__msg_prio); /* Add message pointed by __msg_ptr to message queue __mqdes */ extern int mq_send(mqd_t __mqdes, const char *__msg_ptr, size_t __msg_len, unsigned int __msg_prio); #ifdef __USE_XOPEN2K /* * Receive the oldest from highest priority messages in message queue * __mqdes, stop waiting if __abs_timeout expires. */ extern ssize_t mq_timedreceive(mqd_t __mqdes, char *__restrict __msg_ptr, size_t __msg_len, unsigned int *__restrict __msg_prio, const struct timespec *__restrict __abs_timeout); /* * Add message pointed by __msg_ptr to message queue __mqdes, stop blocking * on full message queue if __abs_timeout expires. */ extern int mq_timedsend(mqd_t __mqdes, const char *__msg_ptr, size_t __msg_len, unsigned int __msg_prio, const struct timespec *__abs_timeout); #endif __END_DECLS #endif