Support customizing BlockedThreadChecker

[dano]

Signed-off-by: Dan O'Reilly oreilldf@gmail.com

Adds support for customizing the implementation of BlockedThreadChecker, exposing an API that allows users to pass a callback that will be executed whenever a thread is blocked for longer than the allowed duration. To use the API, users have to call the blockedThreadChecker() getter on VertxInternal.

Motivation:
In my application, I want to be able to restart the JVM if thread stay blocked for an extended period of time, so that my application can potentially self-heal if something goes very wrong and a thread ends up stuck forever. It's currently not possible to do this (at least as far as I can tell). Adding this new API makes it possible.

[vietj]

the BlockedThreadChecker class should be moved to a impl.btc package and the nested class event should become a regular class instead.

[vietj]

you can call `disableThreadChecks()` to disable thread checks

…

On Wed, Feb 23, 2022 at 2:55 PM dano ***@***.***> wrote: ***@***.**** commented on this pull request. ------------------------------ In src/test/java/io/vertx/core/BlockedThreadCheckerTest.java <#4283 (comment)>: > + VertxOptions vertxOptions = new VertxOptions(); + vertxOptions.setMaxWorkerExecuteTime(maxWorkerExecuteTime); + vertxOptions.setMaxWorkerExecuteTimeUnit(maxWorkerExecuteTimeUnit); + vertxOptions.setWarningExceptionTime(warningExceptionTime); + vertxOptions.setWarningExceptionTimeUnit(warningExceptionTimeUnit); + Vertx newVertx = vertx(vertxOptions); + ((VertxInternal) newVertx).blockedThreadChecker().setThreadBlockedHandler(bte -> { + Assert.assertEquals(NANOSECONDS.convert(maxWorkerExecuteTime, maxWorkerExecuteTimeUnit), bte.maxExecTime); + Assert.assertEquals(NANOSECONDS.convert(warningExceptionTime, warningExceptionTimeUnit), bte.warningExceptionTime); + cl.countDown(); + }); + DeploymentOptions deploymentOptions = new DeploymentOptions(); + deploymentOptions.setWorker(true); + newVertx.deployVerticle(verticle, deploymentOptions); + await(); + awaitLatch(cl); @vietj <https://github.com/vietj> I tried to do it this way initially, but the testComplete() and assert* methods provided by the base class have checks to make sure they are called from an event loop thread, which means the test fails when they get called from the BlockedThreadChecker thread. I could use runOnContext to get back on an event loop thread inside of the threadBlockedHandler, though. Do you prefer that to using the CountdownLatch? — Reply to this email directly, view it on GitHub <#4283 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AABXDCRHSJK4IGJM3EJON43U4TRNRANCNFSM5O7I63LQ> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[vietj]

minor change on BlockedThreadEvent and we are good to go

[vietj]

thanks for the contribution @dano