mirror of
https://github.com/fluencelabs/redis
synced 2025-03-18 00:20:50 +00:00
b7b2a1cc5e
When system time changes back, the timer will not worker properly hence some core functionality of redis will stop working(e.g. replication, bgsave, etc). See issue #633 for details. The patch saves the previous time and when a system clock skew is detected, it will force expire all timers. Modiifed by @antirez: the previous time was moved into the eventLoop structure to make sure the library is still thread safe as long as you use different event loops into different threads (otherwise you need some synchronization). More comments added about the reasoning at the base of the patch, that's worth reporting here: /* If the system clock is moved to the future, and then set back to the * right value, time events may be delayed in a random way. Often this * means that scheduled operations will not be performed soon enough. * * Here we try to detect system clock skews, and force all the time * events to be processed ASAP when this happens: the idea is that * processing events earlier is less dangerous than delaying them * indefinitely, and practice suggests it is. */
119 lines
4.4 KiB
C
119 lines
4.4 KiB
C
/* A simple event-driven programming library. Originally I wrote this code
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* for the Jim's event-loop (Jim is a Tcl interpreter) but later translated
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* it in form of a library for easy reuse.
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*
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* Copyright (c) 2006-2010, Salvatore Sanfilippo <antirez at gmail dot com>
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* All rights reserved.
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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 are met:
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*
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* * Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* * 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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* * Neither the name of Redis nor the names of its contributors may be used
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* to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef __AE_H__
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#define __AE_H__
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#define AE_OK 0
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#define AE_ERR -1
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#define AE_NONE 0
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#define AE_READABLE 1
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#define AE_WRITABLE 2
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#define AE_FILE_EVENTS 1
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#define AE_TIME_EVENTS 2
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#define AE_ALL_EVENTS (AE_FILE_EVENTS|AE_TIME_EVENTS)
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#define AE_DONT_WAIT 4
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#define AE_NOMORE -1
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/* Macros */
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#define AE_NOTUSED(V) ((void) V)
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struct aeEventLoop;
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/* Types and data structures */
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typedef void aeFileProc(struct aeEventLoop *eventLoop, int fd, void *clientData, int mask);
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typedef int aeTimeProc(struct aeEventLoop *eventLoop, long long id, void *clientData);
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typedef void aeEventFinalizerProc(struct aeEventLoop *eventLoop, void *clientData);
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typedef void aeBeforeSleepProc(struct aeEventLoop *eventLoop);
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/* File event structure */
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typedef struct aeFileEvent {
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int mask; /* one of AE_(READABLE|WRITABLE) */
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aeFileProc *rfileProc;
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aeFileProc *wfileProc;
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void *clientData;
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} aeFileEvent;
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/* Time event structure */
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typedef struct aeTimeEvent {
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long long id; /* time event identifier. */
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long when_sec; /* seconds */
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long when_ms; /* milliseconds */
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aeTimeProc *timeProc;
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aeEventFinalizerProc *finalizerProc;
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void *clientData;
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struct aeTimeEvent *next;
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} aeTimeEvent;
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/* A fired event */
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typedef struct aeFiredEvent {
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int fd;
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int mask;
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} aeFiredEvent;
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/* State of an event based program */
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typedef struct aeEventLoop {
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int maxfd; /* highest file descriptor currently registered */
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int setsize; /* max number of file descriptors tracked */
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long long timeEventNextId;
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time_t lastTime; /* Used to detect system clock skew */
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aeFileEvent *events; /* Registered events */
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aeFiredEvent *fired; /* Fired events */
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aeTimeEvent *timeEventHead;
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int stop;
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void *apidata; /* This is used for polling API specific data */
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aeBeforeSleepProc *beforesleep;
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} aeEventLoop;
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/* Prototypes */
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aeEventLoop *aeCreateEventLoop(int setsize);
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void aeDeleteEventLoop(aeEventLoop *eventLoop);
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void aeStop(aeEventLoop *eventLoop);
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int aeCreateFileEvent(aeEventLoop *eventLoop, int fd, int mask,
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aeFileProc *proc, void *clientData);
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void aeDeleteFileEvent(aeEventLoop *eventLoop, int fd, int mask);
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int aeGetFileEvents(aeEventLoop *eventLoop, int fd);
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long long aeCreateTimeEvent(aeEventLoop *eventLoop, long long milliseconds,
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aeTimeProc *proc, void *clientData,
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aeEventFinalizerProc *finalizerProc);
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int aeDeleteTimeEvent(aeEventLoop *eventLoop, long long id);
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int aeProcessEvents(aeEventLoop *eventLoop, int flags);
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int aeWait(int fd, int mask, long long milliseconds);
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void aeMain(aeEventLoop *eventLoop);
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char *aeGetApiName(void);
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void aeSetBeforeSleepProc(aeEventLoop *eventLoop, aeBeforeSleepProc *beforesleep);
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#endif
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