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/*
* Copyright 2016 Garrett D'Amore <garrett@damore.org>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom
* the Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifndef CORE_MSGQUEUE_H
#define CORE_MSGQUEUE_H
#include "nng.h"
/*
* Message queues. Message queues work in some ways like Go channels;
* they are a thread-safe way to pass messages between subsystems.
*/
typedef struct nni_msgqueue *nni_msgqueue_t;
/*
* nni_msgqueue_create creates a message queue with the given capacity,
* which must be a positive number. It returns NNG_EINVAL if the capacity
* is invalid, or NNG_ENOMEM if resources cannot be allocated.
*/
extern int nni_msgqueue_create(nni_msgqueue_t *, int);
/*
* nni_msgqueue_destroy destroys a message queue. It will also free any
* messages that may be in the queue.
*/
extern void nni_msgqueue_destroy(nni_msgqueue_t);
/*
* nni_msgqueue_put attempts to put a message to the queue. It will wait
* for the timeout (us), if the value is positive. If the value is negative
* then it will wait forever. If the value is zero, it will just check, and
* return immediately whether a message can be put or not. Valid returns are
* NNG_ECLOSED if the queue is closed or NNG_ETIMEDOUT if the message cannot
* be placed after a time, or NNG_EAGAIN if the operation cannot succeed
* immediately and a zero timeout is specified. Note that timeout granularity
* may be limited -- for example Windows systems have a millisecond resolution
* timeout capability.
*/
extern int nni_msgqueue_put(nni_msgqueue_t, nng_msg_t, int);
/*
* nni_msgqueue_get gets the message from the queue, using a timeout just
* like nni_msgqueue_put.
*/
extern int nni_msgqueue_get(nni_msgqueue_t, nng_msg_t *, int);
/*
* nni_msgqueue_close closes the queue. After this all operates on the
* message queue will return NNG_ECLOSED. Messages inside the queue
* are freed. Unlike closing a go channel, this operation is idempotent.
*/
extern void nni_msgqueue_close(nni_msgqueue_t);
#endif /* CORE_MSQUEUE_H */
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