From 35b3fbd90c2ad2c503c9e3d28bfbffff13099925 Mon Sep 17 00:00:00 2001 From: Binbin Date: Sun, 9 Oct 2022 13:18:34 +0800 Subject: Freeze time sampling during command execution, and scripts (#10300) Freeze time during execution of scripts and all other commands. This means that a key is either expired or not, and doesn't change state during a script execution. resolves #10182 This PR try to add a new `commandTimeSnapshot` function. The function logic is extracted from `keyIsExpired`, but the related calls to `fixed_time_expire` and `mstime()` are removed, see below. In commands, we will avoid calling `mstime()` multiple times and just use the one that sampled in call. The background is, e.g. using `PEXPIRE 1` with valgrind sometimes result in the key being deleted rather than expired. The reason is that both `PEXPIRE` command and `checkAlreadyExpired` call `mstime()` separately. There are other more important changes in this PR: 1. Eliminate `fixed_time_expire`, it is no longer needed. When we want to sample time we should always use a time snapshot. We will use `in_nested_call` instead to update the cached time in `call`. 2. Move the call for `updateCachedTime` from `serverCron` to `afterSleep`. Now `commandTimeSnapshot` will always return the sample time, the `lookupKeyReadWithFlags` call in `getNodeByQuery` will get a outdated cached time (because `processCommand` is out of the `call` context). We put the call to `updateCachedTime` in `aftersleep`. 3. Cache the time each time the module lock Redis. Call `updateCachedTime` in `moduleGILAfterLock`, affecting `RM_ThreadSafeContextLock` and `RM_ThreadSafeContextTryLock` Currently the commandTimeSnapshot change affects the following TTL commands: - SET EX / SET PX - EXPIRE / PEXPIRE - SETEX / PSETEX - GETEX EX / GETEX PX - TTL / PTTL - EXPIRETIME / PEXPIRETIME - RESTORE key TTL And other commands just use the cached mstime (including TIME). This is considered to be a breaking change since it can break a script that uses a loop to wait for a key to expire. --- tests/unit/scripting.tcl | 112 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) (limited to 'tests/unit') diff --git a/tests/unit/scripting.tcl b/tests/unit/scripting.tcl index 424017832..ca9422787 100644 --- a/tests/unit/scripting.tcl +++ b/tests/unit/scripting.tcl @@ -1376,6 +1376,118 @@ start_server {tags {"scripting needs:debug"}} { r DEBUG set-active-expire 1 } + test "TIME command using cached time" { + set res [run_script { + local result1 = {redis.call("TIME")} + redis.call("DEBUG", "SLEEP", 0.01) + local result2 = {redis.call("TIME")} + return {result1, result2} + } 0] + assert_equal [lindex $res 0] [lindex $res 1] + } + + test "Script block the time in some expiration related commands" { + # The test uses different commands to set the "same" expiration time for different keys, + # and interspersed with "DEBUG SLEEP", to verify that time is frozen in script. + # The commands involved are [P]TTL / SET EX[PX] / [P]EXPIRE / GETEX / [P]SETEX / [P]EXPIRETIME + set res [run_script { + redis.call("SET", "key1{t}", "value", "EX", 1) + redis.call("DEBUG", "SLEEP", 0.01) + + redis.call("SET", "key2{t}", "value", "PX", 1000) + redis.call("DEBUG", "SLEEP", 0.01) + + redis.call("SET", "key3{t}", "value") + redis.call("EXPIRE", "key3{t}", 1) + redis.call("DEBUG", "SLEEP", 0.01) + + redis.call("SET", "key4{t}", "value") + redis.call("PEXPIRE", "key4{t}", 1000) + redis.call("DEBUG", "SLEEP", 0.01) + + redis.call("SETEX", "key5{t}", 1, "value") + redis.call("DEBUG", "SLEEP", 0.01) + + redis.call("PSETEX", "key6{t}", 1000, "value") + redis.call("DEBUG", "SLEEP", 0.01) + + redis.call("SET", "key7{t}", "value") + redis.call("GETEX", "key7{t}", "EX", 1) + redis.call("DEBUG", "SLEEP", 0.01) + + redis.call("SET", "key8{t}", "value") + redis.call("GETEX", "key8{t}", "PX", 1000) + redis.call("DEBUG", "SLEEP", 0.01) + + local ttl_results = {redis.call("TTL", "key1{t}"), + redis.call("TTL", "key2{t}"), + redis.call("TTL", "key3{t}"), + redis.call("TTL", "key4{t}"), + redis.call("TTL", "key5{t}"), + redis.call("TTL", "key6{t}"), + redis.call("TTL", "key7{t}"), + redis.call("TTL", "key8{t}")} + + local pttl_results = {redis.call("PTTL", "key1{t}"), + redis.call("PTTL", "key2{t}"), + redis.call("PTTL", "key3{t}"), + redis.call("PTTL", "key4{t}"), + redis.call("PTTL", "key5{t}"), + redis.call("PTTL", "key6{t}"), + redis.call("PTTL", "key7{t}"), + redis.call("PTTL", "key8{t}")} + + local expiretime_results = {redis.call("EXPIRETIME", "key1{t}"), + redis.call("EXPIRETIME", "key2{t}"), + redis.call("EXPIRETIME", "key3{t}"), + redis.call("EXPIRETIME", "key4{t}"), + redis.call("EXPIRETIME", "key5{t}"), + redis.call("EXPIRETIME", "key6{t}"), + redis.call("EXPIRETIME", "key7{t}"), + redis.call("EXPIRETIME", "key8{t}")} + + local pexpiretime_results = {redis.call("PEXPIRETIME", "key1{t}"), + redis.call("PEXPIRETIME", "key2{t}"), + redis.call("PEXPIRETIME", "key3{t}"), + redis.call("PEXPIRETIME", "key4{t}"), + redis.call("PEXPIRETIME", "key5{t}"), + redis.call("PEXPIRETIME", "key6{t}"), + redis.call("PEXPIRETIME", "key7{t}"), + redis.call("PEXPIRETIME", "key8{t}")} + + return {ttl_results, pttl_results, expiretime_results, pexpiretime_results} + } 8 key1{t} key2{t} key3{t} key4{t} key5{t} key6{t} key7{t} key8{t}] + + # The elements in each list are equal. + assert_equal 1 [llength [lsort -unique [lindex $res 0]]] + assert_equal 1 [llength [lsort -unique [lindex $res 1]]] + assert_equal 1 [llength [lsort -unique [lindex $res 2]]] + assert_equal 1 [llength [lsort -unique [lindex $res 3]]] + + # Then we check that the expiration time is set successfully. + assert_morethan [lindex $res 0] 0 + assert_morethan [lindex $res 1] 0 + assert_morethan [lindex $res 2] 0 + assert_morethan [lindex $res 3] 0 + } + + test "RESTORE expired keys with expiration time" { + set res [run_script { + redis.call("SET", "key1{t}", "value") + local encoded = redis.call("DUMP", "key1{t}") + + redis.call("RESTORE", "key2{t}", 1, encoded, "REPLACE") + redis.call("DEBUG", "SLEEP", 0.01) + redis.call("RESTORE", "key3{t}", 1, encoded, "REPLACE") + + return {redis.call("PEXPIRETIME", "key2{t}"), redis.call("PEXPIRETIME", "key3{t}")} + } 3 key1{t} key2{t} key3{t}] + + # Can get the expiration time and they are all equal. + assert_morethan [lindex $res 0] 0 + assert_equal [lindex $res 0] [lindex $res 1] + } + r debug set-disable-deny-scripts 0 } } ;# foreach is_eval -- cgit v1.2.1