Spring Blocking call under LocalVariableTableParameterNameDiscoverer with Boot JAR loader

Blockhound detects blocking call.

Spring version spring-webflux 5.1.9.RELEASE

JVM version (e.g. java -version) java 11.0.3 2019-04-16 LTS Java(TM) SE Runtime Environment 18.9 (build 11.0.3+12-LTS) Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.3+12-LTS, mixed mode)

OS version (e.g. uname -a) macOS Mojave 10.14.5

    at reactor.blockhound.BlockHound$Builder.lambda$install$8(BlockHound.java:259)
    at reactor.blockhound.BlockHoundRuntime.checkBlocking(BlockHoundRuntime.java:43)
    at java.base/java.io.RandomAccessFile.readBytes(RandomAccessFile.java)
    at java.base/java.io.RandomAccessFile.read(RandomAccessFile.java:406)
    at org.springframework.boot.loader.data.RandomAccessDataFile$FileAccess.read(RandomAccessDataFile.java:222)
    at org.springframework.boot.loader.data.RandomAccessDataFile$FileAccess.access$400(RandomAccessDataFile.java:205)
    at org.springframework.boot.loader.data.RandomAccessDataFile.read(RandomAccessDataFile.java:117)
    at org.springframework.boot.loader.data.RandomAccessDataFile.access$700(RandomAccessDataFile.java:33)
    at org.springframework.boot.loader.data.RandomAccessDataFile$DataInputStream.doRead(RandomAccessDataFile.java:175)
    at org.springframework.boot.loader.data.RandomAccessDataFile$DataInputStream.read(RandomAccessDataFile.java:155)
    at java.base/java.util.zip.InflaterInputStream.fill(InflaterInputStream.java:243)
    at org.springframework.boot.loader.jar.ZipInflaterInputStream.fill(ZipInflaterInputStream.java:68)
    at java.base/java.util.zip.InflaterInputStream.read(InflaterInputStream.java:159)
    at org.springframework.boot.loader.jar.ZipInflaterInputStream.read(ZipInflaterInputStream.java:52)
    at org.springframework.asm.ClassReader.readStream(ClassReader.java:306)
    at org.springframework.asm.ClassReader.<init>(ClassReader.java:273)
    at org.springframework.core.LocalVariableTableParameterNameDiscoverer.inspectClass(LocalVariableTableParameterNameDiscoverer.java:114)
    at org.springframework.core.LocalVariableTableParameterNameDiscoverer.getParameterNames(LocalVariableTableParameterNameDiscoverer.java:74)
    at org.springframework.core.PrioritizedParameterNameDiscoverer.getParameterNames(PrioritizedParameterNameDiscoverer.java:55)
    at org.springframework.core.MethodParameter.getParameterName(MethodParameter.java:622)
    at org.springframework.web.reactive.result.method.annotation.AbstractNamedValueArgumentResolver.updateNamedValueInfo(AbstractNamedValueArgumentResolver.java:145)
    at org.springframework.web.reactive.result.method.annotation.AbstractNamedValueArgumentResolver.getNamedValueInfo(AbstractNamedValueArgumentResolver.java:123)
    at org.springframework.web.reactive.result.method.annotation.AbstractNamedValueArgumentResolver.resolveArgument(AbstractNamedValueArgumentResolver.java:92)
    at org.springframework.web.reactive.result.method.annotation.AbstractNamedValueSyncArgumentResolver.resolveArgument(AbstractNamedValueSyncArgumentResolver.java:64)
    at org.springframework.web.reactive.result.method.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:123)
    at org.springframework.web.reactive.result.method.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:190)
    at org.springframework.web.reactive.result.method.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:133)
    at org.springframework.web.reactive.result.method.annotation.RequestMappingHandlerAdapter.lambda$handle$1(RequestMappingHandlerAdapter.java:200)
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:44)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:153)
    at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoPeekFuseable.subscribe(MonoPeekFuseable.java:74)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoPeekFuseable.subscribe(MonoPeekFuseable.java:74)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:345)
    at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:345)
    at reactor.core.publisher.MonoNext$NextSubscriber.onNext(MonoNext.java:76)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:345)
    at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.innerNext(FluxConcatMap.java:275)
    at reactor.core.publisher.FluxConcatMap$ConcatMapInner.onNext(FluxConcatMap.java:849)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:345)
    at reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:114)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:345)
    at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2071)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.request(FluxOnAssembly.java:442)
    at reactor.core.publisher.FluxMap$MapSubscriber.request(FluxMap.java:155)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.request(FluxOnAssembly.java:442)
    at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.set(Operators.java:1879)
    at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onSubscribe(Operators.java:1753)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onSubscribe(FluxOnAssembly.java:426)
    at reactor.core.publisher.FluxMap$MapSubscriber.onSubscribe(FluxMap.java:86)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onSubscribe(FluxOnAssembly.java:426)
    at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:54)
    at reactor.core.publisher.MonoCallableOnAssembly.subscribe(MonoCallableOnAssembly.java:82)
    at reactor.core.publisher.MonoMap.subscribe(MonoMap.java:55)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.Mono.subscribe(Mono.java:3858)
    at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.drain(FluxConcatMap.java:442)
    at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.onSubscribe(FluxConcatMap.java:212)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onSubscribe(FluxOnAssembly.java:426)
    at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:139)
    at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:63)
    at reactor.core.publisher.FluxOnAssembly.subscribe(FluxOnAssembly.java:122)
    at reactor.core.publisher.FluxConcatMap.subscribe(FluxConcatMap.java:121)
    at reactor.core.publisher.FluxOnAssembly.subscribe(FluxOnAssembly.java:122)
    at reactor.core.publisher.MonoNext.subscribe(MonoNext.java:40)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoSwitchIfEmpty.subscribe(MonoSwitchIfEmpty.java:44)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoFlatMap.subscribe(MonoFlatMap.java:60)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoFlatMap.subscribe(MonoFlatMap.java:60)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:345)
    at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1515)
    at reactor.core.publisher.MonoZip$ZipCoordinator.signal(MonoZip.java:247)
    at reactor.core.publisher.MonoZip$ZipInner.onNext(MonoZip.java:329)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:345)
    at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2071)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.request(FluxOnAssembly.java:442)
    at reactor.core.publisher.MonoZip$ZipInner.onSubscribe(MonoZip.java:318)
    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onSubscribe(FluxOnAssembly.java:426)
    at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:54)
    at reactor.core.publisher.MonoCallableOnAssembly.subscribe(MonoCallableOnAssembly.java:82)
    at reactor.core.publisher.Mono.subscribe(Mono.java:3858)
    at reactor.core.publisher.MonoZip.subscribe(MonoZip.java:128)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoFlatMap.subscribe(MonoFlatMap.java:60)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:56)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:56)
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:56)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:56)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:56)
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:56)
    at reactor.core.publisher.MonoPeekTerminal.subscribe(MonoPeekTerminal.java:61)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoPeekFuseable.subscribe(MonoPeekFuseable.java:74)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:56)
    at reactor.core.publisher.MonoPeekTerminal.subscribe(MonoPeekTerminal.java:61)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.Mono.subscribe(Mono.java:3858)
    at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:172)
    at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:56)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:56)
    at reactor.core.publisher.MonoPeekFuseable.subscribe(MonoPeekFuseable.java:70)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:56)
    at reactor.core.publisher.MonoPeekTerminal.subscribe(MonoPeekTerminal.java:61)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:61)
    at reactor.netty.http.server.HttpServerHandle.onStateChange(HttpServerHandle.java:64)
    at reactor.netty.tcp.TcpServerBind$ChildObserver.onStateChange(TcpServerBind.java:226)
    at reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:442)
    at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:91)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
    at reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:161)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
    at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438)
    at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:328)
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:302)
    at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
    at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1421)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
    at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:930)
    at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:794)
    at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:424)
    at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:326)
    at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:918)
    at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
    at java.base/java.lang.Thread.run(Thread.java:834)

Comment From: rstoyanchev

This is trying to resolve names of controller method parameters by reading the LocalVariableTable (available with debug info) in the class file via ASM, and the class info is read from the Boot jar. Once the parameter info is read, it is then cached in AbstractNamedValueArgumentResolver and is not looked up again. Hence I'm not sure that this is an issue in practice that's worth addressing (e.g. by accessing method parameters on startup in order to force resolution and caching).

On Java 8+, it is possible to get the method parameter names via reflection when the -parameter flag is used. Can you try using that? You read more about it in the Boot docs and also this SO answer.

Comment From: spring-projects-issues

If you would like us to look at this issue, please provide the requested information. If the information is not provided within the next 7 days this issue will be closed.

Comment From: spring-projects-issues

Closing due to lack of requested feedback. If you would like us to look at this issue, please provide the requested information and we will re-open the issue.

Comment From: rstoyanchev

This is essentially the same issue as #24247.