ngx_queue_t *
ngx_queue_middle(ngx_queue_t *queue)
{
ngx_queue_t *middle, *next;
middle = ngx_queue_head(queue);
if (middle == ngx_queue_last(queue)) {
return middle;
}
next = ngx_queue_head(queue);
for ( ;; ) {
middle = ngx_queue_next(middle);
next = ngx_queue_next(next);
if (next == ngx_queue_last(queue)) {
return middle;
}
next = ngx_queue_next(next);
if (next == ngx_queue_last(queue)) {
return middle;
}
}
}
// 参考：http://blog.csdn.net/livelylittlefish/article/details/6607324
// 获得队列的中间节点，(除头节点外)若队列有奇数个节点，则返回中间节点；
// 若队列有偶数个节点，则返回后半个队列的第一个节点;
ngx_queue_t *
ngx_queue_middle(ngx_queue_t *queue)
{
ngx_queue_t *middle, *next;
middle = ngx_queue_head(queue);
//若只有一个元素
if (middle == ngx_queue_last(queue)) {
return middle;
}
next = ngx_queue_head(queue);
// 此循环中，next指针每次移动两个节点，而middle指针每次移动一个节点
for ( ;; ) {
middle = ngx_queue_next(middle);
next = ngx_queue_next(next);
// 偶数个节点，在此返回后半个队列的第一个节点
if (next == ngx_queue_last(queue)) {
return middle;
}
next = ngx_queue_next(next);
// 奇数个节点，在此返回中间节点
if (next == ngx_queue_last(queue)) {
return middle;
}
}
}
int main()
{
ngx_pool_t* pool;
yahoo_guy_t* guy;
ngx_queue_t* q;
yahoo_t* yahoo;
pool = ngx_create_pool(1024*10, NULL); //初始化内存池
int i;
// 构建队列
const ngx_str_t names[] = {
ngx_string("rainx"), ngx_string("xiaozhe"), ngx_string("zhoujian")
} ;
const int ids[] = {4611, 8322, 6111};
yahoo = ngx_palloc(pool, sizeof(yahoo_t));
ngx_queue_init(&yahoo->queue); //初始化queue
for(i = 0; i < 3; i++)
{
guy = (yahoo_guy_t*) ngx_palloc(pool, sizeof(yahoo_guy_t));
guy->id = ids[i];
//guy->name = (char*) ngx_palloc(pool, (size_t) (strlen(names[i]) + 1) );
guy->name = (u_char*) ngx_pstrdup(pool, (ngx_str_t*) &(names[i]) );
ngx_queue_init(&guy->queue);
// 从头部进入队列
ngx_queue_insert_head(&yahoo->queue, &guy->queue);
}
// 从尾部遍历输出
for(q = ngx_queue_last(&yahoo->queue);
q != ngx_queue_sentinel(&yahoo->queue);
q = ngx_queue_prev(q) ) {
guy = ngx_queue_data(q, yahoo_guy_t, queue);
printf("No. %d guy in yahoo is %s \n", guy->id, guy->name);
}
// 排序从头部输出
ngx_queue_sort(&yahoo->queue, yahoo_no_cmp);
printf("sorting....\n");
for(q = ngx_queue_prev(&yahoo->queue);
q != ngx_queue_sentinel(&yahoo->queue);
q = ngx_queue_last(q) ) {
guy = ngx_queue_data(q, yahoo_guy_t, queue);
printf("No. %d guy in yahoo is %s \n", guy->id, guy->name);
}
ngx_destroy_pool(pool);
return 0;
}
// cmp 指向函数的指针
// 队列排序采用的是稳定的简单插入排序方法，即从第一个节点开始遍历，依次将节点(q)插入前面已经排序好的队列(链表)中
// prev 为已经排序好的queue
void
ngx_queue_sort(ngx_queue_t *queue,
ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *))
{
ngx_queue_t *q, *prev, *next;
q = ngx_queue_head(queue);
// 若只有一个元素，则无须排序
if (q == ngx_queue_last(queue)) {
return;
}
for (q = ngx_queue_next(q); q != ngx_queue_sentinel(queue); q = next) {
prev = ngx_queue_prev(q);
// 也充当了循环条件
next = ngx_queue_next(q);
ngx_queue_remove(q);
do {
// 指针函数调用
if (cmp(prev, q) <= 0) {
break;
}
prev = ngx_queue_prev(prev);
} while (prev != ngx_queue_sentinel(queue));
ngx_queue_insert_after(prev, q);
}
}
static void
ngx_resolver_expire(ngx_resolver_t *r, ngx_rbtree_t *tree, ngx_queue_t *queue)
{
time_t now;
ngx_uint_t i;
ngx_queue_t *q;
ngx_resolver_node_t *rn;
ngx_log_debug0(NGX_LOG_DEBUG_CORE, r->log, 0, "resolver expire");
now = ngx_time();
for (i = 0; i < 2; i++) {
if (ngx_queue_empty(queue)) {
return;
}
q = ngx_queue_last(queue);
rn = ngx_queue_data(q, ngx_resolver_node_t, queue);
if (now <= rn->expire) {
return;
}
ngx_log_debug2(NGX_LOG_DEBUG_CORE, r->log, 0,
"resolver expire \"%*s\"", (size_t) rn->nlen, rn->name);
ngx_queue_remove(q);
ngx_rbtree_delete(tree, &rn->node);
ngx_resolver_free_node(r, rn);
}
}
static void
ngx_http_v2_waiting_queue(ngx_http_v2_connection_t *h2c,
ngx_http_v2_stream_t *stream)
{
ngx_queue_t *q;
ngx_http_v2_stream_t *s;
if (stream->handled) {
return;
}
stream->handled = 1;
for (q = ngx_queue_last(&h2c->waiting);
q != ngx_queue_sentinel(&h2c->waiting);
q = ngx_queue_prev(q))
{
s = ngx_queue_data(q, ngx_http_v2_stream_t, queue);
if (s->node->rank < stream->node->rank
|| (s->node->rank == stream->node->rank
&& s->node->rel_weight >= stream->node->rel_weight))
{
break;
}
}
ngx_queue_insert_after(q, &stream->queue);
}
void
ngx_queue_sort(ngx_queue_t *queue,
intptr_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *))
{
ngx_queue_t *q, *prev, *next;
q = ngx_queue_head(queue);
if (q == ngx_queue_last(queue)) {
return;
}
for (q = ngx_queue_next(q); q != ngx_queue_sentinel(queue); q = next) {
prev = ngx_queue_prev(q);
next = ngx_queue_next(q);
ngx_queue_remove(q);
do {
if (cmp(prev, q) <= 0) {
break;
}
prev = ngx_queue_prev(prev);
} while (prev != ngx_queue_sentinel(queue));
ngx_queue_insert_after(prev, q);
}
}
// free_connections 中没有可用的连接, 从reusable_connections_queue获取
static void
ngx_drain_connections(void)
{
ngx_int_t i;
ngx_queue_t *q;
ngx_connection_t *c;
// 清理32个keepalive连接，以回收一些连接池供新连接使用
for (i = 0; i < 32; i++) {
if (ngx_queue_empty(&ngx_cycle->reusable_connections_queue)) {
break;
}
// reusable连接队列是从头插入的，意味着越靠近队列尾部的连接，空闲未被
// 使用的时间就越长，这种情况下，优先回收它，类似LRU
q = ngx_queue_last(&ngx_cycle->reusable_connections_queue);
c = ngx_queue_data(q, ngx_connection_t, queue);
ngx_log_debug0(NGX_LOG_DEBUG_CORE, c->log, 0,
"reusing connection");
// 这里的handler是ngx_http_keepalive_handler，这函数里，由于close被置1，
// 所以会执行ngx_http_close_connection来释放连接，这样也就发生了keepalive
// 连接被强制断掉的现象了。
c->close = 1;
c->read->handler(c->read);
}
}
static void
ngx_ssl_expire_sessions(ngx_ssl_session_cache_t *cache,
ngx_slab_pool_t *shpool, ngx_uint_t n)
{
time_t now, then;
ngx_queue_t *q;
ngx_ssl_sess_id_t *sess_id;
now = ngx_time();
while (n < 3) {
if (ngx_queue_empty(&cache->expire_queue)) {
return;
}
q = ngx_queue_last(&cache->expire_queue);
sess_id = ngx_queue_data(q, ngx_ssl_sess_id_t, queue);
then = (time_t) sess_id->session->peer_cert;
if (n++ != 0 && then > now) {
return;
}
ngx_queue_remove(q);
ngx_rbtree_delete(&cache->session_rbtree, &sess_id->node);
ngx_slab_free_locked(shpool, sess_id->session);
ngx_slab_free_locked(shpool, sess_id);
}
}
void
ngx_queue_sort(ngx_queue_t *queue,
ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *))
{
ngx_queue_t *q, *prev, *next;
q = ngx_queue_head(queue);
if (q == ngx_queue_last(queue)) {
return;
}
for (q = ngx_queue_next(q); q != ngx_queue_sentinel(queue); q = next) {
prev = ngx_queue_prev(q);
next = ngx_queue_next(q);
ngx_queue_remove(q);
do {
if (cmp(prev, q) <= 0) {/* 比较 */
break;
}
prev = ngx_queue_prev(prev); /* prev指针前移 */
} while (prev != ngx_queue_sentinel(queue));
ngx_queue_insert_after(prev, q);/* 将q插入prev节点之后(此处即为简单插入) */
}
}
static void
ngx_http_spdy_waiting_queue(ngx_http_spdy_connection_t *sc,
ngx_http_spdy_stream_t *stream)
{
ngx_queue_t *q;
ngx_http_spdy_stream_t *s;
if (stream->handled)
{
return;
}
stream->handled = 1;
for (q = ngx_queue_last(&sc->waiting);
q != ngx_queue_sentinel(&sc->waiting);
q = ngx_queue_prev(q))
{
s = ngx_queue_data(q, ngx_http_spdy_stream_t, queue);
/*
* NB: higher values represent lower priorities.
*/
if (stream->priority >= s->priority)
{
break;
}
}
ngx_queue_insert_after(q, &stream->queue);
}
void
ngx_http_tfs_rc_server_expire(ngx_http_tfs_rc_ctx_t *ctx)
{
ngx_queue_t *q, *kp_q;
ngx_rbtree_node_t *node;
ngx_http_tfs_rcs_info_t *rc_info_node;
if (ngx_queue_empty(&ctx->sh->queue)) {
return;
}
q = ngx_queue_last(&ctx->sh->queue);
rc_info_node = ngx_queue_data(q, ngx_http_tfs_rcs_info_t, queue);
kp_q = &rc_info_node->kp_queue;
ngx_queue_remove(q);
ngx_queue_remove(kp_q);
node = (ngx_rbtree_node_t *)
((u_char *) rc_info_node - offsetof(ngx_rbtree_node_t, color));
ngx_rbtree_delete(&ctx->sh->rbtree, node);
ngx_http_tfs_rc_server_destroy_node(ctx, rc_info_node);
}
static ngx_uint_t
ngx_http_viewer_cache_node_count(ngx_http_file_cache_t *cache)
{
ngx_queue_t *q;
ngx_uint_t count;
ngx_http_file_cache_node_t *fcn;
count = 0;
ngx_shmtx_lock(&cache->shpool->mutex);
for (q = ngx_queue_last(&cache->sh->queue);
q != ngx_queue_sentinel(&cache->sh->queue);
q = ngx_queue_prev(q))
{
fcn = ngx_queue_data(q, ngx_http_file_cache_node_t, queue);
ngx_log_debug6(NGX_LOG_DEBUG_HTTP, ngx_cycle->log, 0,
"http viewer file cache: #%d %d %02xd%02xd%02xd%02xd",
fcn->count, fcn->exists,
fcn->key[0], fcn->key[1], fcn->key[2], fcn->key[3]);
count++;
}
ngx_shmtx_unlock(&cache->shpool->mutex);
return count;
}
static void
ngx_http_req_status_expire(void *conf)
{
ngx_queue_t *q;
ngx_http_req_status_zone_t *ctx = conf;
ngx_http_req_status_node_t *ssn;
if (ngx_queue_empty(&ctx->sh->queue)) {
return;
}
if (ctx->sh->expire_lock > ngx_time()){
return;
}
q = ngx_queue_last(&ctx->sh->queue);
ssn = ngx_queue_data(q, ngx_http_req_status_node_t, queue);
if (!ssn->data.requests || (ngx_current_msec > ssn->last_traffic_update &&
ngx_current_msec - ssn->last_traffic_update >= 10 * 1000)){
ngx_log_debug2(NGX_LOG_DEBUG_HTTP, ngx_cycle->log, 0,
"req-status, release node, zone = \"%V\", key = \"%s\"",
&ctx->shm_zone->shm.name, ssn->key);
ngx_queue_remove(q);
ngx_rbtree_delete(&ctx->sh->rbtree, &ssn->node);
ngx_slab_free_locked(ctx->shpool, ssn);
}
}
/*
* [analy] 队列排序采用的是稳定的简单插入排序方法，即从第一个节点开始遍历，依次将当前节点(q)插入前面已经排好序的队列(链表)中
* 由于排序仅简单的修改了指针指向的操作，所以效率较高的。
*/
void
ngx_queue_sort(ngx_queue_t *queue,
ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *))
{
ngx_queue_t *q, *prev, *next;
q = ngx_queue_head(queue);
if (q == ngx_queue_last(queue)) { // 第一个节点和最后一个节点相等，不需要排序（有0或1个节点）
return;
}
for (q = ngx_queue_next(q); q != ngx_queue_sentinel(queue); q = next) {
prev = ngx_queue_prev(q); // 取当前节点的前一个节点
next = ngx_queue_next(q); // 取当前节点的后一个节点
ngx_queue_remove(q); // 删除当前节点
do {
if (cmp(prev, q) <= 0) {
break;
}
prev = ngx_queue_prev(prev); // 这里取前一个节点的目的是为了检查循环条件是否成立，如果成立说明头节点之后还有节点，需要继续比较
// 不成立，说明头结点之后已经无接点，直接插入到头结点后
} while (prev != ngx_queue_sentinel(queue));
ngx_queue_insert_after(prev, q);
}
}
//shpool is assumed to be locked.
static ngx_http_push_msg_t *ngx_http_push_get_latest_message_locked(ngx_http_push_channel_t * channel) {
ngx_queue_t *sentinel = &channel->message_queue->queue;
if(ngx_queue_empty(sentinel)) {
return NULL;
}
ngx_queue_t *qmsg = ngx_queue_last(sentinel);
return ngx_queue_data(qmsg, ngx_http_push_msg_t, queue);
}
static void
ngx_http_limit_req2_expire(ngx_http_request_t *r, ngx_http_limit_req2_ctx_t *ctx,
ngx_uint_t n)
{
ngx_int_t excess;
ngx_time_t *tp;
ngx_msec_t now;
ngx_queue_t *q;
ngx_msec_int_t ms;
ngx_rbtree_node_t *node;
ngx_http_limit_req2_node_t *lr;
tp = ngx_timeofday();
now = (ngx_msec_t) (tp->sec * 1000 + tp->msec);
/*
* n == 1 deletes one or two zero rate entries
* n == 0 deletes oldest entry by force
* and one or two zero rate entries
*/
while (n < 3) {
if (ngx_queue_empty(&ctx->sh->queue)) {
return;
}
q = ngx_queue_last(&ctx->sh->queue);
lr = ngx_queue_data(q, ngx_http_limit_req2_node_t, queue);
if (n++ != 0) {
ms = (ngx_msec_int_t) (now - lr->last);
ms = ngx_abs(ms);
if (ms < 60000) {
return;
}
excess = lr->excess - ctx->rate * ms / 1000;
if (excess > 0) {
return;
}
}
ngx_queue_remove(q);
node = (ngx_rbtree_node_t *)
((u_char *) lr - offsetof(ngx_rbtree_node_t, color));
ngx_rbtree_delete(&ctx->sh->rbtree, node);
ngx_slab_free_locked(ctx->shpool, node);
}
}
static int
ngx_tcp_lua_shdict_expire(ngx_tcp_lua_shdict_ctx_t *ctx, ngx_uint_t n)
{
ngx_time_t *tp;
uint64_t now;
ngx_queue_t *q;
int64_t ms;
ngx_rbtree_node_t *node;
ngx_tcp_lua_shdict_node_t *sd;
int freed = 0;
tp = ngx_timeofday();
now = (uint64_t) tp->sec * 1000 + tp->msec;
/*
* n == 1 deletes one or two expired entries
* n == 0 deletes oldest entry by force
* and one or two zero rate entries
*/
while (n < 3) {
if (ngx_queue_empty(&ctx->sh->queue)) {
return freed;
}
q = ngx_queue_last(&ctx->sh->queue);
sd = ngx_queue_data(q, ngx_tcp_lua_shdict_node_t, queue);
if (n++ != 0) {
if (sd->expires == 0) {
return freed;
}
ms = sd->expires - now;
if (ms > 0) {
return freed;
}
}
ngx_queue_remove(q);
node = (ngx_rbtree_node_t *)
((u_char *) sd - offsetof(ngx_rbtree_node_t, color));
ngx_rbtree_delete(&ctx->sh->rbtree, node);
ngx_slab_free_locked(ctx->shpool, node);
freed++;
}
return freed;
}
static void
ngx_http_create_locations_list(ngx_queue_t *locations, ngx_queue_t *q)
{
u_char *name;
size_t len;
ngx_queue_t *x, tail;
ngx_http_location_queue_t *lq, *lx;
if (q == ngx_queue_last(locations)) {
return;
}
lq = (ngx_http_location_queue_t *) q;
if (lq->inclusive == NULL) {
ngx_http_create_locations_list(locations, ngx_queue_next(q));
return;
}
len = lq->name->len;
name = lq->name->data;
for (x = ngx_queue_next(q);
x != ngx_queue_sentinel(locations);
x = ngx_queue_next(x))
{
lx = (ngx_http_location_queue_t *) x;
if (len > lx->name->len
|| (ngx_strncmp(name, lx->name->data, len) != 0))
{
break;
}
}
q = ngx_queue_next(q);
if (q == x) {
ngx_http_create_locations_list(locations, x);
return;
}
ngx_queue_split(locations, q, &tail);
ngx_queue_add(&lq->list, &tail);
if (x == ngx_queue_sentinel(locations)) {
ngx_http_create_locations_list(&lq->list, ngx_queue_head(&lq->list));
return;
}
ngx_queue_split(&lq->list, x, &tail);
ngx_queue_add(locations, &tail);
ngx_http_create_locations_list(&lq->list, ngx_queue_head(&lq->list));
ngx_http_create_locations_list(locations, x);
}
static void
ngx_http_ip_behavior_expire(ngx_http_ip_behavior_ctx_t *ctx, ngx_uint_t force)
{
ngx_time_t *tp;
ngx_msec_t now;
ngx_msec_int_t ms;
ngx_queue_t *q;
ngx_rbtree_node_t *node;
ngx_http_ip_behavior_node_t *ibn;
ngx_uint_t i;
ngx_uint_t n;
tp = ngx_timeofday();
now = (ngx_msec_t) (tp->sec * 1000 + tp->msec);
/* delete at most 2 oldest nodes when a new request comes in
* or
* delete 10 oldest nodes ignoring the expires when "force" is set to 1
*/
if (force) {
n = 10;
} else {
n = 2;
}
for (i = 0; i < n; i++) {
if (ngx_queue_empty(&ctx->sh->queue)) {
return;
}
q = ngx_queue_last(&ctx->sh->queue);
ibn = ngx_queue_data(q, ngx_http_ip_behavior_node_t, queue);
if (!force) {
ms = (ngx_msec_int_t) (now - ibn->last);
ms = ngx_abs(ms);
if (ms < ctx->sample_cycle) {
/* the oldest is not expired, no need to check prev nodes */
return;
}
}
ngx_queue_remove(q);
node = (ngx_rbtree_node_t *)
((u_char *) ibn - offsetof(ngx_rbtree_node_t, color));
ngx_rbtree_delete(&ctx->sh->rbtree, node);
ngx_slab_free_locked(ctx->shpool, node);
}
}
void
ngx_empty_into(ngx_queue_t *from,ngx_queue_t *to,int limit)
{
ngx_queue_t *q;
while (!ngx_queue_empty(from) && limit-- != 0) {
q = ngx_queue_last(from);
ngx_queue_remove(q);
ngx_queue_insert_head(to,q);
}
}
static max_connections_peer_data_t *
queue_oldest (max_connections_srv_conf_t *maxconn_cf)
{
if(ngx_queue_empty(&maxconn_cf->waiting_requests))
return NULL;
ngx_queue_t *last = ngx_queue_last(&maxconn_cf->waiting_requests);
max_connections_peer_data_t *peer_data =
ngx_queue_data(last, max_connections_peer_data_t, queue);
return peer_data;
}
static void
ngx_open_file_cache_cleanup(void *data)
{
ngx_open_file_cache_t *cache = data;
ngx_queue_t *q;
ngx_cached_open_file_t *file;
ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0,
"open file cache cleanup");
for ( ;; ) {
if (ngx_queue_empty(&cache->expire_queue)) {
break;
}
q = ngx_queue_last(&cache->expire_queue);
file = ngx_queue_data(q, ngx_cached_open_file_t, queue);
ngx_queue_remove(q);
ngx_rbtree_delete(&cache->rbtree, &file->node);
cache->current--;
ngx_log_debug1(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0,
"delete cached open file: %s", file->name);
if (!file->err && !file->is_dir) {
file->close = 1;
file->count = 0;
ngx_close_cached_file(cache, file, 0, ngx_cycle->log);
} else {
ngx_free(file->name);
ngx_free(file);
}
}
if (cache->current) {
ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
"%ui items still leave in open file cache",
cache->current);
}
if (cache->rbtree.root != cache->rbtree.sentinel) {
ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
"rbtree still is not empty in open file cache");
}
}
int ngx_shmap_flush_expired(ngx_shm_zone_t* zone, int attempts)
{
ngx_queue_t *q, *prev;
ngx_shmap_node_t *sd;
ngx_shmap_ctx_t *ctx;
ngx_time_t *tp;
int freed = 0;
ngx_rbtree_node_t *node;
uint64_t now;
assert(zone != NULL);
ctx = zone->data;
ngx_shmtx_lock(&ctx->shpool->mutex);
if (ngx_queue_empty(&ctx->sh->queue)) {
return 0;
}
tp = ngx_timeofday();
now = (uint64_t) tp->sec * 1000 + tp->msec;
q = ngx_queue_last(&ctx->sh->queue);
while (q != ngx_queue_sentinel(&ctx->sh->queue)) {
prev = ngx_queue_prev(q);
sd = ngx_queue_data(q, ngx_shmap_node_t, queue);
if (sd->expires != 0 && sd->expires <= now) {
ngx_queue_remove(q);
node = (ngx_rbtree_node_t *)
((u_char *) sd - offsetof(ngx_rbtree_node_t, color));
ngx_rbtree_delete(&ctx->sh->rbtree, node);
ngx_slab_free_locked(ctx->shpool, node);
freed++;
if (attempts && freed == attempts) {
break;
}
}
q = prev;
}
ngx_shmtx_unlock(&ctx->shpool->mutex);
return freed;
}
void dump_queue_from_tail(ngx_queue_t *que)
{
ngx_queue_t *q = ngx_queue_last(que);
printf("(0x%x: (0x%x, 0x%x)) <==> \n", que, que->prev, que->next);
for (; q != ngx_queue_sentinel(que); q = ngx_queue_prev(q))
{
my_point_queue_t *point = ngx_queue_data(q, my_point_queue_t, queue);
printf("(0x%x: (%-2d, %-2d), 0x%x: (0x%x, 0x%x)) <==> \n", point, point->point.x,
point->point.y, &point->queue, point->queue.prev, point->queue.next);
}
}
static void
ngx_expire_old_cached_files(ngx_open_file_cache_t *cache, ngx_uint_t n,
ngx_log_t *log)
{
time_t now;
ngx_queue_t *q;
ngx_cached_open_file_t *file;
now = ngx_time();
/*
* n == 1 deletes one or two inactive files
* n == 0 deletes least recently used file by force
* and one or two inactive files
*/
while (n < 3) {
// 如果队列为空，则直接返回
if (ngx_queue_empty(&cache->expire_queue)) {
return;
}
// 取出最后一个文件，也就是可能需要被超时的文件
// (因为尾部是最长时间没有操作的文件)
q = ngx_queue_last(&cache->expire_queue);
file = ngx_queue_data(q, ngx_cached_open_file_t, queue);
// n是控制是强制超时，还是按inactive超时，后一个判断是判断是否超时
if (n++ != 0 && now - file->accessed <= cache->inactive) {
return;
}
// 如果有超时的，或者需要强制超时，则开始从队列和红黑树中移除
ngx_queue_remove(q);
ngx_rbtree_delete(&cache->rbtree, &file->node);
cache->current--;
ngx_log_debug1(NGX_LOG_DEBUG_CORE, log, 0,
"expire cached open file: %s", file->name);
if (!file->err && !file->is_dir) {
file->close = 1;
// 关闭文件
ngx_close_cached_file(cache, file, 0, log);
} else {
ngx_free(file->name);
ngx_free(file);
}
}
}
static void
ngx_btt_expire(ngx_event_t *ev)
{
#if 0
time_t now;
ngx_uint_t i;
ngx_queue_t *q;
#endif
ngx_btt_conf_t *bcf;
#if 0
ngx_btt_torrent_t *t;
#endif
ngx_log_debug0(NGX_LOG_DEBUG_CORE, ev->log, 0, "btt expire");
bcf = ev->data;
#if 0
if (!ngx_shmtx_trylock(&bcf->pool->mutex)) {
goto done;
}
now = ngx_time();
for (i = 0; i < 2; i++) {
if (ngx_queue_empty(&bcf->cache->queue)) {
break;
}
q = ngx_queue_last(&bcf->cache->queue);
code = ngx_queue_data(q, ngx_btt_torrent_t, queue);
if (code->expire >= now) {
break;
}
ngx_log_debug1(NGX_LOG_DEBUG_CORE, ev->log, 0,
"lua cache expire node \"%V\"", &code->path);
ngx_queue_remove(&code->queue);
ngx_rbtree_delete(&bcf->cache->rbtree, &code->node);
ngx_slab_free_locked(bcf->pool, code);
}
ngx_shmtx_unlock(&bcf->pool->mutex);
done:
#endif
ngx_add_timer(&bcf->event, bcf->expire * 1000 / 10);
}
static void
ngx_http_limit_traffic_rate_filter_cleanup(void *data)
{
ngx_http_limit_traffic_rate_filter_cleanup_t *lircln = data;
ngx_slab_pool_t *shpool;
ngx_rbtree_node_t *node;
ngx_http_limit_traffic_rate_filter_ctx_t *ctx;
ngx_http_limit_traffic_rate_filter_node_t *lir;
ctx = lircln->shm_zone->data;
shpool = (ngx_slab_pool_t *) lircln->shm_zone->shm.addr;
node = lircln->node;
lir = (ngx_http_limit_traffic_rate_filter_node_t *) &node->color;
ngx_shmtx_lock(&shpool->mutex);
ngx_log_debug2(NGX_LOG_DEBUG_HTTP, lircln->shm_zone->shm.log, 0,
"limit traffic rate cleanup: %08XD %d", node->key, lir->conn);
lir->conn--;
if (lir->conn == 0) {
ngx_queue_t *p = lir->rq_top.next;
ngx_queue_t *c;
ngx_http_limit_traffic_rate_filter_request_queue_t * tr;
for(; p; ){
c = p;
p = ngx_queue_next(p);
if(ngx_queue_next(c) && ngx_queue_prev(c)){
ngx_queue_remove(c);
}
tr = ngx_queue_data(c, ngx_http_limit_traffic_rate_filter_request_queue_t, rq);
if (!tr->r){
ngx_slab_free_locked(shpool, tr);
}
if(ngx_queue_last(&lir->rq_top) == p){
break;
}
}
ngx_rbtree_delete(ctx->rbtree, node);
ngx_slab_free_locked(shpool, node);
}
ngx_shmtx_unlock(&shpool->mutex);
}
static void
ngx_expire_old_cached_files(ngx_open_file_cache_t *cache, ngx_uint_t n,
ngx_log_t *log)
{
time_t now;
ngx_queue_t *q;
ngx_cached_open_file_t *file;
now = ngx_time();
/*
* n == 1 deletes one or two inactive files
* n == 0 deletes least recently used file by force
* and one or two inactive files
*/
while (n < 3) {
if (ngx_queue_empty(&cache->expire_queue)) {
return;
}
q = ngx_queue_last(&cache->expire_queue);
file = ngx_queue_data(q, ngx_cached_open_file_t, queue);
if (n++ != 0 && now - file->accessed <= cache->inactive) {
return;
}
ngx_queue_remove(q);
ngx_rbtree_delete(&cache->rbtree, &file->node);
cache->current--;
ngx_log_debug1(NGX_LOG_DEBUG_CORE, log, 0,
"expire cached open file: %s", file->name);
if (!file->err && !file->is_dir) {
file->close = 1;
ngx_close_cached_file(cache, file, 0, log);
} else {
ngx_free(file->name);
ngx_free(file);
}
}
}
static time_t
ngx_resolver_resend(ngx_resolver_t *r, ngx_rbtree_t *tree, ngx_queue_t *queue)
{
time_t now;
ngx_queue_t *q;
ngx_resolver_node_t *rn;
now = ngx_time();
for ( ;; ) {
if (ngx_queue_empty(queue)) {
return 0;
}
q = ngx_queue_last(queue);
rn = ngx_queue_data(q, ngx_resolver_node_t, queue);
if (now < rn->expire) {
return rn->expire - now;
}
ngx_log_debug3(NGX_LOG_DEBUG_CORE, r->log, 0,
"resolver resend \"%*s\" %p",
(size_t) rn->nlen, rn->name, rn->waiting);
ngx_queue_remove(q);
if (rn->waiting) {
if (ngx_resolver_send_query(r, rn) == NGX_OK) {
rn->expire = now + r->resend_timeout;
ngx_queue_insert_head(queue, &rn->queue);
}
continue;
}
ngx_rbtree_delete(tree, &rn->node);
ngx_resolver_free_node(r, rn);
}
}
