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693c24ef9d
Libevent's current timeout code is relatively optimized for the randomly scattered timeout case, where events are added with their timeouts in no particular order. We add and remove timeouts with O(lg n) behavior. Frequently, however, an application will want to have many timeouts of the same value. For example, we might have 1000 bufferevents, each with a 2 second timeout on reading or writing. If we knew this were always the case, we could just put timeouts in a queue and get O(1) add and remove behavior. Of course, a queue would give O(n) performance for a scattered timeout pattern, so we don't want to just switch the implementation. This patch gives the user the ability to explicitly tag certain timeout values as being "very common". These timeout values have a cookie encoded in the high bits of their tv_usec field to indicate which queue they belong on. The queues themselves are each triggered by an entry in the minheap. See the regress_main.c code for an example use. svn:r1517
155 lines
4.2 KiB
C
155 lines
4.2 KiB
C
/*
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* Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
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* Copyright (c) 2007-2009 Niels Provos and Nick Mathewson
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef _EVENT2_EVENT_STRUCT_H_
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#define _EVENT2_EVENT_STRUCT_H_
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/** @file event_struct.h
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Structures used by event.h. Using these structures directly may harm
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forward compatibility: be careful!
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*/
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include <event-config.h>
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#ifdef _EVENT_HAVE_SYS_TYPES_H
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#include <sys/types.h>
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#endif
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#ifdef _EVENT_HAVE_SYS_TIME_H
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#include <sys/time.h>
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#endif
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/* For int types. */
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#include <event2/util.h>
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#ifdef WIN32
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#include <winsock2.h>
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#define WIN32_LEAN_AND_MEAN
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#include <windows.h>
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#undef WIN32_LEAN_AND_MEAN
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#endif
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#define EVLIST_TIMEOUT 0x01
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#define EVLIST_INSERTED 0x02
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#define EVLIST_SIGNAL 0x04
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#define EVLIST_ACTIVE 0x08
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#define EVLIST_INTERNAL 0x10
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#define EVLIST_INIT 0x80
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/* EVLIST_X_ Private space: 0x1000-0xf000 */
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#define EVLIST_ALL (0xf000 | 0x9f)
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/* Fix so that people don't have to run with <sys/queue.h> */
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#ifndef TAILQ_ENTRY
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#define _EVENT_DEFINED_TQENTRY
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#define TAILQ_ENTRY(type) \
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struct { \
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struct type *tqe_next; /* next element */ \
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struct type **tqe_prev; /* address of previous next element */ \
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}
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#endif /* !TAILQ_ENTRY */
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struct event_base;
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struct event {
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TAILQ_ENTRY (event) (ev_active_next);
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TAILQ_ENTRY (event) (ev_next);
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/* for managing timeouts */
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union {
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TAILQ_ENTRY (event) (ev_next_with_common_timeout);
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int min_heap_idx;
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} ev_timeout_pos;
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evutil_socket_t ev_fd;
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struct event_base *ev_base;
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union {
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/* used for io events */
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struct {
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TAILQ_ENTRY (event) (ev_io_next);
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struct timeval ev_timeout;
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} ev_io;
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/* used by signal events */
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struct {
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TAILQ_ENTRY (event) (ev_signal_next);
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short ev_ncalls;
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/* Allows deletes in callback */
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short *ev_pncalls;
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} ev_signal;
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} _ev;
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short ev_events;
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short ev_res; /* result passed to event callback */
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short ev_flags;
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ev_uint8_t ev_pri; /* smaller numbers are higher priority */
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ev_uint8_t ev_closure;
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struct timeval ev_timeout;
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/* allows us to adopt for different types of events */
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void (*ev_callback)(evutil_socket_t, short, void *arg);
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void *ev_arg;
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};
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#ifdef EVENT_FD
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/* This was defined in event.h, but since we're including event_struct.h, we
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* can use the faster versions. */
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#undef EVENT_FD
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#undef EVENT_SIGNAL
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#define EVENT_SIGNAL(ev) ((int)(ev)->ev_fd)
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#define EVENT_FD(ev) ((int)(ev)->ev_fd)
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#endif
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/*
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* Key-Value pairs. Can be used for HTTP headers but also for
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* query argument parsing.
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*/
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struct evkeyval {
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TAILQ_ENTRY(evkeyval) next;
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char *key;
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char *value;
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};
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#ifdef _EVENT_DEFINED_TQENTRY
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#undef TAILQ_ENTRY
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struct event_list;
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struct evkeyvalq;
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#undef _EVENT_DEFINED_TQENTRY
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#else
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TAILQ_HEAD (event_list, event);
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TAILQ_HEAD (evkeyvalq, evkeyval);
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#endif /* _EVENT_DEFINED_TQENTRY */
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#ifdef __cplusplus
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}
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#endif
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#endif /* _EVENT2_EVENT_STRUCT_H_ */
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