Commit e542132b authored by zhaozhao.zz's avatar zhaozhao.zz Committed by antirez
Browse files

expires: refactoring judgment about whether a key is expired

Calling lookupKey*() many times to search a key in one command
may get different result.

That's because lookupKey*() calls expireIfNeeded(), and delete
the key when reach the expire time. So we can get an robj before
the expire time, but a NULL after the expire time.

The worst is that may lead to Redis crash, for example
`RPOPLPUSH foo foo` the first time we get a list form `foo` and
hold the pointer, but when we get `foo` again it's expired and
deleted. Now we hold a freed memory, when execute rpoplpushHandlePush()
redis crash.

To fix it, we can refactor the judgment about whether a key is expired,
using the same basetime `server.cmd_start_mstime` instead of calling
mstime() everytime.
parent fdaea2a7
......@@ -1199,7 +1199,7 @@ int keyIsExpired(redisDb *db, robj *key) {
* only the first time it is accessed and not in the middle of the
* script execution, making propagation to slaves / AOF consistent.
* See issue #1525 on Github for more information. */
mstime_t now = server.lua_caller ? server.lua_time_start : mstime();
mstime_t now = server.lua_caller ? server.lua_time_start : server.cmd_start_mstime;
return now > when;
}
......
......@@ -3596,6 +3596,7 @@ int processCommand(client *c) {
queueMultiCommand(c);
addReply(c,shared.queued);
} else {
server.cmd_start_mstime = mstime();
call(c,CMD_CALL_FULL);
c->woff = server.master_repl_offset;
if (listLength(server.ready_keys))
......
......@@ -1401,6 +1401,7 @@ struct redisServer {
time_t timezone; /* Cached timezone. As set by tzset(). */
int daylight_active; /* Currently in daylight saving time. */
long long mstime; /* 'unixtime' with milliseconds resolution. */
mstime_t cmd_start_mstime;
/* Pubsub */
dict *pubsub_channels; /* Map channels to list of subscribed clients */
list *pubsub_patterns; /* A list of pubsub_patterns */
......
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