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/*
* iSCSI event queue
*
* Copyright (C) 2004 Dmitry Yusupov, Alex Aizman
* maintained by open-iscsi@googlegroups.com
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* See the file COPYING included with this distribution for more details.
*/
#include <stdlib.h>
#include <string.h>
#include <search.h>
#include "queue.h"
#include "log.h"
#include "actor.h"
queue_t*
queue_create(int pages_initial, int pages_max, queued_f queued,
void *queued_data)
{
queue_t *queue;
if ((queue = malloc(sizeof(queue_t))) == NULL) {
log_error("out of memory when allocating queue_t");
return NULL;
}
queue->queued_func = queued;
queue->queued_data = queued_data;
queue->pages_current = pages_initial;
queue->start_ptr = malloc(queue->pages_current * QUEUE_BUF_SIZE);
if (queue->start_ptr == NULL) {
log_error("out of memory when allocating queue's pages");
free(queue);
return NULL;
}
memset(queue->start_ptr, 0, queue->pages_current * QUEUE_BUF_SIZE);
queue->head_ptr = queue->tail_ptr = queue->start_ptr;
queue->end_ptr = (char *)queue->start_ptr +
queue->pages_current * QUEUE_BUF_SIZE;
queue->pages_initial = pages_initial;
queue->pages_max = pages_max;
queue->list_head.q_forw = &queue->list_head;
queue->list_head.q_back = &queue->list_head;
queue->count = 0;
return queue;
}
void
queue_destroy(queue_t* queue)
{
if (queue->list_head.q_forw != &queue->list_head) {
log_error("destroying non-empty queue 0x%p", queue);
}
free(queue->start_ptr);
free(queue);
}
static queue_status_e
__io_queue_grow(queue_t *queue)
{
void *newbuf, *oldbuf;
struct qelem *item;
queue_item_t *elem;
log_debug(7, "queue 0x%p:%d is growing", queue, queue->pages_current);
newbuf = malloc((queue->pages_current + 1) * QUEUE_BUF_SIZE);
if (newbuf == NULL) {
return QUEUE_OUT_OF_MEMORY;
}
memcpy(newbuf, queue->start_ptr, queue->pages_current * QUEUE_BUF_SIZE);
oldbuf = queue->start_ptr;
/* adjust queue sizes */
queue->start_ptr = newbuf;
queue->end_ptr = (char *)newbuf +
(queue->pages_current + 1) * QUEUE_BUF_SIZE;
queue->tail_ptr = (char *)newbuf + ((char *)queue->tail_ptr -
(char *)oldbuf);
queue->head_ptr = (char *)newbuf + ((char *)queue->head_ptr -
(char *)oldbuf);
queue->list_head.q_forw = (struct qelem *) (void *)((char *)newbuf +
((char *)queue->list_head.q_forw - (char *)oldbuf));
queue->list_head.q_back = (struct qelem *) (void *)((char *)newbuf +
((char *)queue->list_head.q_back - (char *)oldbuf));
/* adjust queue list */
for (item = queue->list_head.q_forw;
item != queue->list_head.q_forw; item = item->q_forw) {
elem = (queue_item_t *)item;
if (elem->item.q_forw != &queue->list_head) {
elem->item.q_forw =
(struct qelem *)(void *)((char *)newbuf +
((char *)elem->item.q_forw - (char *)oldbuf));
}
if (elem->item.q_back != &queue->list_head) {
elem->item.q_back =
(struct qelem *) (void *)((char *)newbuf +
((char *)elem->item.q_back - (char *)oldbuf));
}
}
free(oldbuf);
queue->pages_current++;
return QUEUE_OK;
}
queue_status_e
queue_consume(queue_t *queue, int data_max_size, queue_item_t *item)
{
int real_size;
queue_item_t *elem;
if (queue->list_head.q_forw == &queue->list_head) {
if (queue->count)
log_error("queue integrety lost! Bug?");
return QUEUE_IS_EMPTY;
}
elem = (queue_item_t *)queue->list_head.q_forw;
if (elem->data_size > data_max_size) {
return QUEUE_NOT_ENOUGH_SPACE;
}
remque(&elem->item);
real_size = elem->data_size + sizeof(queue_item_t);
if (queue->head_ptr == elem) {
queue->head_ptr = (char *)queue->head_ptr + real_size;
log_debug(7,
"event_type: %d removing from the head: "
"0x%p:0x%p:0x%p:0x%p elem 0x%p length %d",
elem->event_type,
queue->start_ptr,
queue->head_ptr,
queue->tail_ptr,
queue->end_ptr,
elem,
real_size);
} else if ((char *)queue->tail_ptr - real_size == (char*)elem) {
queue->tail_ptr = (char *)queue->tail_ptr - real_size;
log_debug(7,
"event_type: %d removing from the tail: "
"0x%p:0x%p:0x%p:0x%p elem 0x%p length %d",
elem->event_type,
queue->start_ptr,
queue->head_ptr,
queue->tail_ptr,
queue->end_ptr,
elem,
real_size);
} else {
log_debug(7,
"event_type: %d removing from the list: "
"0x%p:0x%p:0x%p:0x%p elem 0x%p length %d",
elem->event_type,
queue->start_ptr,
queue->head_ptr,
queue->tail_ptr,
queue->end_ptr,
elem,
real_size);
}
memcpy(item, elem, sizeof(queue_item_t));
memcpy(queue_item_data(item), queue_item_data(elem), elem->data_size);
if (queue->list_head.q_forw == &queue->list_head) {
/* reset buffer pointers just to be clean */
queue->head_ptr = queue->tail_ptr = queue->start_ptr;
}
queue->count--;
return QUEUE_OK;
}
void*
queue_item_data (queue_item_t *item)
{
return (char *)item + sizeof(queue_item_t);
}
queue_status_e
queue_produce(queue_t *queue, int event_type, void *context,
const int data_size, void *data)
{
int real_size = data_size + sizeof(queue_item_t);
queue_item_t *elem;
try_again:
if ((char *)queue->tail_ptr + real_size <= (char *)queue->end_ptr) {
elem = queue->tail_ptr;
queue->tail_ptr = (void *)((char *)queue->tail_ptr + real_size);
log_debug(7, "event_type: %d adding to the tail: "
"0x%p:0x%p:0x%p:0x%p elem 0x%p length %d",
event_type,
queue->start_ptr,
queue->head_ptr,
queue->tail_ptr,
queue->end_ptr,
elem,
real_size);
} else if ((char *)queue->head_ptr - real_size >=
(char *)queue->start_ptr) {
elem = (void *)((char *)queue->head_ptr - real_size);
queue->head_ptr = elem;
log_debug(7, "event_type: %d adding to the head: "
"0x%p:0x%p:0x%p:0x%p length %d",
event_type,
queue->start_ptr,
queue->head_ptr,
queue->tail_ptr,
queue->end_ptr,
real_size);
} else {
queue_status_e status;
if (queue->pages_current >= queue->pages_max) {
return QUEUE_IS_FULL;
}
/* grow */
status = __io_queue_grow(queue);
if (status != QUEUE_OK) {
return status;
}
goto try_again;
}
elem->data_size = data_size;
elem->event_type = event_type;
elem->context = context;
memcpy(queue_item_data(elem), data, data_size);
insque(&elem->item, queue->list_head.q_back);
if (queue->queued_func)
queue->queued_func(queue->queued_data, event_type);
queue->count++;
return QUEUE_OK;
}
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