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Diffstat (limited to 'src/core/msgqueue.h')
| -rw-r--r-- | src/core/msgqueue.h | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/src/core/msgqueue.h b/src/core/msgqueue.h new file mode 100644 index 00000000..9d856edd --- /dev/null +++ b/src/core/msgqueue.h @@ -0,0 +1,73 @@ +/* + * 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 */ |
