[crac] RFR: Reset JVM start time and up time on restore (CRaCResetStartTime)

[Radim Vansa]

On Tue, 17 Oct 2023 09:29:35 GMT, Roman Marchenko <rmarchenko at openjdk.org> wrote:

> This change adds an opportunity reset both JVM's start time and uptime on restoring.
> 
> Resetting time may be performed with the new flag "-XX:+CRaCResetStartTime".
> 
> The flag is 'false' by default.

src/hotspot/os/linux/crac_linux.cpp line 468:

> 466: 
> 467: void crac::initialize_time_counters() {
> 468:   os::Posix::init();

The initialization updates some condition variable attributes; have you checked if there's any chance that another  thread could observe an inconsistent state while this is updated?

test/jdk/jdk/crac/ResetStartTimeTest.java line 40:

> 38:  * @library /test/lib
> 39:  * @build SimpleTest
> 40:  * @requires (os.family == "linux")

I think that if you use simengine the test is applicable to other platforms as well.

test/jdk/jdk/crac/ResetStartTimeTest.java line 44:

> 42:  * @run driver/timeout=60 jdk.test.lib.crac.CracTest true
> 43:  */
> 44: public class SimpleTest implements CracTest {

Could you please name the test `ResetStartTimeTest` to match the filename?

test/jdk/jdk/crac/ResetStartTimeTest.java line 75:

> 73:             assertLessThan(uptime1, WAIT_TIMEOUT);
> 74:         } else {
> 75:             assertLessThan(uptime0, uptime1);

If the C/R is really quick this should be <=

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PR Review Comment: https://git.openjdk.org/crac/pull/130#discussion_r1361985624
PR Review Comment: https://git.openjdk.org/crac/pull/130#discussion_r1361962742
PR Review Comment: https://git.openjdk.org/crac/pull/130#discussion_r1361959649
PR Review Comment: https://git.openjdk.org/crac/pull/130#discussion_r1361962107