Replace `synchonized` block with `ReentrantLock` to make virtual thread friendly

[ikhoon]

There is a current known limitation that code should avoid using a synchronized block for the virtual thread.

Related work:

• https://github.com/pgjdbc/pgjdbc/issues/1951
• https://github.com/netty/netty/pull/12633

[Bue-von-hon]

hello @ikhoon I would like to work on this issue Could you please provide a little more information e.g. XXX.class has to be fix.(it seem to be so many file has sync block) Thank you very much in advance.

[ikhoon]

We need to fix all classes in Armeria that use synchronized blocks. It is difficult to fix all files at once. Why don't we divide the files into each module?

$ ag --java --ignore-dir gen-src -w -c synchronized 
rxjava3/src/main/java/com/linecorp/armeria/common/rxjava3/RequestContextAssembly.java:2
rxjava2/src/main/java/com/linecorp/armeria/common/rxjava2/RequestContextAssembly.java:2
core/src/main/java/com/linecorp/armeria/internal/server/servlet/ServletTlsAttributes.java:1
core/src/main/java/com/linecorp/armeria/internal/server/annotation/AnnotatedValueResolver.java:1
core/src/main/java/com/linecorp/armeria/internal/server/annotation/AnnotatedBeanFactoryRegistry.java:1
core/src/main/java/com/linecorp/armeria/internal/common/util/MinifiedBouncyCastleProvider.java:2
core/src/main/java/com/linecorp/armeria/internal/common/stream/TwoElementFixedStreamMessage.java:1
core/src/main/java/com/linecorp/armeria/internal/common/ReflectiveDependencyInjector.java:2
core/src/main/java/com/linecorp/armeria/internal/common/metric/CaffeineMetricSupport.java:2
core/src/main/java/com/linecorp/armeria/server/healthcheck/HealthCheckService.java:3
core/src/main/java/com/linecorp/armeria/server/Server.java:6
core/src/main/java/com/linecorp/armeria/common/util/AbstractOption.java:3
core/src/main/java/com/linecorp/armeria/common/util/AbstractListenable.java:3
core/src/main/java/com/linecorp/armeria/common/util/ShutdownHooks.java:1
core/src/main/java/com/linecorp/armeria/common/util/CompositeException.java:2
core/src/main/java/com/linecorp/armeria/common/util/StartStopSupport.java:3
core/src/main/java/com/linecorp/armeria/common/DefaultConcurrentAttributes.java:3
core/src/main/java/com/linecorp/armeria/common/stream/DefaultStreamMessageDuplicator.java:1
core/src/main/java/com/linecorp/armeria/common/stream/DefaultStreamMessage.java:1
core/src/main/java/com/linecorp/armeria/common/DefaultDependencyInjector.java:2
core/src/main/java/com/linecorp/armeria/common/logging/RequestScopedMdc.java:4
core/src/main/java/com/linecorp/armeria/common/logging/DefaultRequestLog.java:2
core/src/main/java/com/linecorp/armeria/client/DefaultEventLoopScheduler.java:1
core/src/main/java/com/linecorp/armeria/client/OneEventLoopState.java:2
core/src/main/java/com/linecorp/armeria/client/HeapBasedEventLoopState.java:2
core/src/main/java/com/linecorp/armeria/client/endpoint/healthcheck/HealthCheckedEndpointGroup.java:6
core/src/main/java/com/linecorp/armeria/client/endpoint/healthcheck/HttpHealthChecker.java:2
core/src/main/java/com/linecorp/armeria/client/endpoint/FileWatcherRegistry.java:3
core/src/main/java/com/linecorp/armeria/client/endpoint/healthcheck/DefaultHealthCheckerContext.java:7
core/src/main/java/com/linecorp/armeria/client/endpoint/WeightedRandomDistributionEndpointSelector.java:1
core/src/main/java/com/linecorp/armeria/client/endpoint/RestartableThread.java:2
tomcat9/src/main/java/com/linecorp/armeria/server/tomcat/JarSubsetResourceSet.java:1
grpc/src/test/java/com/linecorp/armeria/internal/common/grpc/TestServiceImpl.java:7
grpc/src/main/java/com/linecorp/armeria/internal/client/grpc/ArmeriaClientCall.java:1
grpc/src/main/java/com/linecorp/armeria/server/grpc/AbstractServerCall.java:2
grpc/src/main/java/com/linecorp/armeria/server/grpc/GrpcHealthCheckService.java:4
retrofit2/src/main/java/com/linecorp/armeria/client/retrofit2/ArmeriaCallFactory.java:1
retrofit2/src/main/java/com/linecorp/armeria/client/retrofit2/PipeBuffer.java:5
resteasy/src/main/java/com/linecorp/armeria/server/resteasy/ResteasyAsynchronousResponseImpl.java:6
grpc-protocol/src/main/java/com/linecorp/armeria/common/grpc/protocol/AbstractMessageDeframer.java:2
benchmarks/jmh/src/jmh/java/com/linecorp/armeria/common/stream/StreamMessageBenchmark.java:1
reactor3/src/main/java/com/linecorp/armeria/common/reactor3/RequestContextHooks.java:2
spring/boot2-webflux-autoconfigure/src/main/java/com/linecorp/armeria/spring/web/reactive/ArmeriaWebServer.java:2
spring/boot2-autoconfigure/src/main/java/com/linecorp/armeria/spring/AbstractArmeriaBeanPostProcessor.java:2

We may start with common/util and move on to client/endpoint and so on. In fact, the order does not matter. You can pick anything you want. 😉

[Bue-von-hon]

thank you kindly then i'll start with common/util until early next week (it has 12 sync block)👍👍

[mscheong01]

I'm also willing to do a part if it's welcome 😄

[Bue-von-hon]

I'm also willing to do a part if it's welcome 😄

glad to work with you!! @j-min5u 😆 i'm working on common/util What is it like for you to work on client/endpoint if it's ok

[mscheong01]

@Bue-von-hon Sure 😸 I'll get to it 🙌 I'll also see if I could remove the other three files under client/

[ikhoon]

If all migration has finished, it would be worth prohibiting synchronized block with a checkstyle rule.

[mscheong01]

I'll do internal/ + server/ next @Bue-von-hon if you do the other files under common/, we'll be done with the core module 😃

[Bue-von-hon]

I'll do internal/ + server/ next @Bue-von-hon if you do the other files under common/, we'll be done with the core module 😃

ok I'll replace under common/🛠

[daniel-itunu]

@Bue-von-hon @j-min5u joining you guys here. what other module are yet to be done?

[Bue-von-hon]

@Bue-von-hon @j-min5u joining you guys here. what other module are yet to be done?

@daniel-itunu I'm working on a common module right now.🙂

[daniel-itunu]

@Bue-von-hon @j-min5u joining you guys here. what other module are yet to be done?

@daniel-itunu I'm working on a common module right now.🙂 Nice, thanks. taking a look.

[mscheong01]

@daniel-itunu we're currently working on the core module. you could work on other modules like rxjava2/, rxjava3/, grpc/, retrofit2/, etc