Mercurial > hg > nginx-quic
view src/event/ngx_event_timer.c @ 6957:83bae3d354ab
HTTP/2: fixed connection finalization.
All streams in connection must be finalized before the connection
itself can be finalized and all related memory is freed. That's
not always possible on the current event loop iteration.
Thus when the last stream is finalized, it sets the special read
event handler ngx_http_v2_handle_connection_handler() and posts
the event.
Previously, this handler didn't check the connection state and
could call the regular event handler on a connection that was
already in finalization stage. In the worst case that could
lead to a segmentation fault, since some data structures aren't
supposed to be used during connection finalization. Particularly,
the waiting queue can contain already freed streams, so the
WINDOW_UPDATE frame received by that moment could trigger
accessing to these freed streams.
Now, the connection error flag is explicitly checked in
ngx_http_v2_handle_connection_handler().
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Wed, 29 Mar 2017 20:21:01 +0300 |
parents | 03928f7f209b |
children | 0c5e84096d99 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> ngx_rbtree_t ngx_event_timer_rbtree; static ngx_rbtree_node_t ngx_event_timer_sentinel; /* * the event timer rbtree may contain the duplicate keys, however, * it should not be a problem, because we use the rbtree to find * a minimum timer value only */ ngx_int_t ngx_event_timer_init(ngx_log_t *log) { ngx_rbtree_init(&ngx_event_timer_rbtree, &ngx_event_timer_sentinel, ngx_rbtree_insert_timer_value); return NGX_OK; } ngx_msec_t ngx_event_find_timer(void) { ngx_msec_int_t timer; ngx_rbtree_node_t *node, *root, *sentinel; if (ngx_event_timer_rbtree.root == &ngx_event_timer_sentinel) { return NGX_TIMER_INFINITE; } root = ngx_event_timer_rbtree.root; sentinel = ngx_event_timer_rbtree.sentinel; node = ngx_rbtree_min(root, sentinel); timer = (ngx_msec_int_t) (node->key - ngx_current_msec); return (ngx_msec_t) (timer > 0 ? timer : 0); } void ngx_event_expire_timers(void) { ngx_event_t *ev; ngx_rbtree_node_t *node, *root, *sentinel; sentinel = ngx_event_timer_rbtree.sentinel; for ( ;; ) { root = ngx_event_timer_rbtree.root; if (root == sentinel) { return; } node = ngx_rbtree_min(root, sentinel); /* node->key > ngx_current_msec */ if ((ngx_msec_int_t) (node->key - ngx_current_msec) > 0) { return; } ev = (ngx_event_t *) ((char *) node - offsetof(ngx_event_t, timer)); ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0, "event timer del: %d: %M", ngx_event_ident(ev->data), ev->timer.key); ngx_rbtree_delete(&ngx_event_timer_rbtree, &ev->timer); #if (NGX_DEBUG) ev->timer.left = NULL; ev->timer.right = NULL; ev->timer.parent = NULL; #endif ev->timer_set = 0; ev->timedout = 1; ev->handler(ev); } } ngx_int_t ngx_event_no_timers_left(void) { ngx_event_t *ev; ngx_rbtree_node_t *node, *root, *sentinel; sentinel = ngx_event_timer_rbtree.sentinel; root = ngx_event_timer_rbtree.root; if (root == sentinel) { return NGX_OK; } for (node = ngx_rbtree_min(root, sentinel); node; node = ngx_rbtree_next(&ngx_event_timer_rbtree, node)) { ev = (ngx_event_t *) ((char *) node - offsetof(ngx_event_t, timer)); if (!ev->cancelable) { return NGX_AGAIN; } } /* only cancelable timers left */ return NGX_OK; }