You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

148 lines
4.4 KiB

9 years ago
/*
Copyright (c) 2012-2013 Martin Sustrik All rights reserved.
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.
*/
#include "msgqueue.h"
#include "../../utils/alloc.h"
#include "../../utils/fast.h"
#include "../../utils/err.h"
#include <string.h>
void nn_msgqueue_init (struct nn_msgqueue *self, size_t maxmem)
{
struct nn_msgqueue_chunk *chunk;
self->count = 0;
self->mem = 0;
self->maxmem = maxmem;
chunk = nn_alloc (sizeof (struct nn_msgqueue_chunk), "msgqueue chunk");
alloc_assert (chunk);
chunk->next = NULL;
self->out.chunk = chunk;
self->out.pos = 0;
self->in.chunk = chunk;
self->in.pos = 0;
self->cache = NULL;
}
void nn_msgqueue_term (struct nn_msgqueue *self)
{
int rc;
struct nn_msg msg;
/* Deallocate messages in the pipe. */
while (1) {
rc = nn_msgqueue_recv (self, &msg);
if (rc == -EAGAIN)
break;
errnum_assert (rc >= 0, -rc);
nn_msg_term (&msg);
}
/* There are no more messages in the pipe so there's at most one chunk
in the queue. Deallocate it. */
nn_assert (self->in.chunk == self->out.chunk);
nn_free (self->in.chunk);
/* Deallocate the cached chunk, if any. */
if (self->cache)
nn_free (self->cache);
}
int nn_msgqueue_empty (struct nn_msgqueue *self)
{
return self->count == 0 ? 1 : 0;
}
int nn_msgqueue_send (struct nn_msgqueue *self, struct nn_msg *msg)
{
size_t msgsz;
/* By allowing one message of arbitrary size to be written to the queue,
we allow even messages that exceed max buffer size to pass through.
Beyond that we'll apply the buffer limit as specified by the user. */
msgsz = nn_chunkref_size (&msg->sphdr) + nn_chunkref_size (&msg->body);
if (nn_slow (self->count > 0 && self->mem + msgsz >= self->maxmem))
return -EAGAIN;
/* Adjust the statistics. */
++self->count;
self->mem += msgsz;
/* Move the content of the message to the pipe. */
nn_msg_mv (&self->out.chunk->msgs [self->out.pos], msg);
++self->out.pos;
/* If there's no space for a new message in the pipe, either re-use
the cache chunk or allocate a new chunk if it does not exist. */
if (nn_slow (self->out.pos == NN_MSGQUEUE_GRANULARITY)) {
if (nn_slow (!self->cache)) {
self->cache = nn_alloc (sizeof (struct nn_msgqueue_chunk),
"msgqueue chunk");
alloc_assert (self->cache);
self->cache->next = NULL;
}
self->out.chunk->next = self->cache;
self->out.chunk = self->cache;
self->cache = NULL;
self->out.pos = 0;
}
return 0;
}
int nn_msgqueue_recv (struct nn_msgqueue *self, struct nn_msg *msg)
{
struct nn_msgqueue_chunk *o;
/* If there is no message in the queue. */
if (nn_slow (!self->count))
return -EAGAIN;
/* Move the message from the pipe to the user. */
nn_msg_mv (msg, &self->in.chunk->msgs [self->in.pos]);
/* Move to the next position. */
++self->in.pos;
if (nn_slow (self->in.pos == NN_MSGQUEUE_GRANULARITY)) {
o = self->in.chunk;
self->in.chunk = self->in.chunk->next;
self->in.pos = 0;
if (nn_fast (!self->cache))
self->cache = o;
else
nn_free (o);
}
/* Adjust the statistics. */
--self->count;
self->mem -= (nn_chunkref_size (&msg->sphdr) +
nn_chunkref_size (&msg->body));
return 0;
}