Don't block the event loop when reading inputstream.

http-server-netty/src/main/java/io/micronaut/http/server/netty/binders/InputStreamBodyBinder.java

@@ -73,62 +73,80 @@ public BindingResult<InputStream> bind(ArgumentConversionContext<InputStream> co
             NettyHttpRequest nettyHttpRequest = (NettyHttpRequest) source;
             io.netty.handler.codec.http.HttpRequest nativeRequest = nettyHttpRequest.getNativeRequest();
             if (nativeRequest instanceof StreamedHttpRequest) {
-                HttpContentProcessor<ByteBufHolder> processor = (HttpContentProcessor<ByteBufHolder>) processorResolver.resolve(nettyHttpRequest, context.getArgument());
                 PipedOutputStream outputStream = new PipedOutputStream();
                 try {
-                    PipedInputStream inputStream = new PipedInputStream(outputStream);
-                    processor.subscribe(new CompletionAwareSubscriber<ByteBufHolder>() {
+                    PipedInputStream inputStream = new PipedInputStream(outputStream) {
+                        private volatile HttpContentProcessor<ByteBufHolder> processor;
 
-                        @Override
-                        protected void doOnSubscribe(Subscription subscription) {
-                            subscription.request(1);
-                        }
+                        private void init() {
+                            if (processor == null) {
+                                processor = (HttpContentProcessor<ByteBufHolder>) processorResolver.resolve(nettyHttpRequest, context.getArgument());
+                                processor.subscribe(new CompletionAwareSubscriber<ByteBufHolder>() {
 
-                        @Override
-                        protected void doOnNext(ByteBufHolder message) {
-                            if (LOG.isTraceEnabled()) {
-                                LOG.trace("Server received streaming message for argument [{}]: {}", context.getArgument(), message);
-                            }
-                            ByteBuf content = message.content();
-                            if (!(content instanceof EmptyByteBuf)) {
-                                try {
-                                    byte[] bytes = ByteBufUtil.getBytes(content);
-                                    outputStream.write(bytes, 0, bytes.length);
-                                } catch (IOException e) {
-                                    subscription.cancel();
-                                    return;
-                                } finally {
-                                    content.release();
-                                }
+                                    @Override
+                                    protected void doOnSubscribe(Subscription subscription) {
+                                        subscription.request(1);
+                                    }
+
+                                    @Override
+                                    protected synchronized void doOnNext(ByteBufHolder message) {
+                                        if (LOG.isTraceEnabled()) {
+                                            LOG.trace("Server received streaming message for argument [{}]: {}", context.getArgument(), message);
+                                        }
+                                        ByteBuf content = message.content();
+                                        if (!(content instanceof EmptyByteBuf)) {
+                                            try {
+                                                byte[] bytes = ByteBufUtil.getBytes(content);
+                                                outputStream.write(bytes, 0, bytes.length);
+                                            } catch (IOException e) {
+                                                subscription.cancel();
+                                                return;
+                                            } finally {
+                                                content.release();
+                                            }
+                                        }
+                                        subscription.request(1);
+                                    }
+
+                                    @Override
+                                    protected synchronized void doOnError(Throwable t) {
+                                        if (LOG.isTraceEnabled()) {
+                                            LOG.trace("Server received error for argument [" + context.getArgument() + "]: " + t.getMessage(), t);
+                                        }
+                                        try {
+                                            outputStream.close();
+                                        } catch (IOException ignored) {
+                                        } finally {
+                                            subscription.cancel();
+                                        }
+                                    }
+
+                                    @Override
+                                    protected synchronized void doOnComplete() {
+                                        if (LOG.isTraceEnabled()) {
+                                            LOG.trace("Done receiving messages for argument: {}", context.getArgument());
+                                        }
+                                        try {
+                                            outputStream.close();
+                                        } catch (IOException ignored) {
+                                        }
+                                    }
+                                });
                             }
-                            subscription.request(1);
                         }
 
                         @Override
-                        protected void doOnError(Throwable t) {
-                            if (LOG.isTraceEnabled()) {
-                                LOG.trace("Server received error for argument [" + context.getArgument() + "]: " + t.getMessage(), t);
-                            }
-                            try {
-                                outputStream.close();
-                            } catch (IOException ignored) {
-                            } finally {
-                                subscription.cancel();
-                            }
+                        public synchronized int read(byte[] b, int off, int len) throws IOException {
+                            init();
+                            return super.read(b, off, len);
                         }
 
                         @Override
-                        protected void doOnComplete() {
-                            if (LOG.isTraceEnabled()) {
-                                LOG.trace("Done receiving messages for argument: {}", context.getArgument());
-                            }
-                            try {
-                                outputStream.close();
-                            } catch (IOException ignored) {
-                            }
+                        public synchronized int read() throws IOException {
+                            init();
+                            return super.read();
                         }
-
-                    });
+                    };
 
                     return () -> Optional.of(inputStream);
                 } catch (IOException e) {

http-server-netty/src/test/groovy/io/micronaut/http/server/netty/stream/InputStreamBodySpec.groovy

@@ -0,0 +1,117 @@
+package io.micronaut.http.server.netty.stream
+
+import io.micronaut.context.ApplicationContext
+import io.micronaut.http.*
+import io.micronaut.http.annotation.*
+import io.micronaut.http.client.HttpClient
+import io.micronaut.http.client.annotation.Client
+import io.micronaut.http.client.exceptions.HttpClientResponseException
+import io.micronaut.http.client.multipart.MultipartBody
+import io.micronaut.runtime.server.EmbeddedServer
+import io.micronaut.scheduling.TaskExecutors
+import io.micronaut.scheduling.annotation.ExecuteOn
+import jakarta.inject.Inject
+import spock.lang.AutoCleanup
+import spock.lang.Issue
+import spock.lang.Shared
+import spock.lang.Specification
+
+import javax.annotation.Nullable
+import java.util.concurrent.ConcurrentLinkedQueue
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.ExecutorService
+import java.util.concurrent.Executors
+
+class InputStreamBodySpec extends Specification {
+
+    @Shared @AutoCleanup EmbeddedServer embeddedServer = ApplicationContext.run(EmbeddedServer)
+
+    @Issue('https://github.com/micronaut-projects/micronaut-core/issues/6100')
+    void "test apply load to InputStream read"() {
+        given:
+        HttpClient client = embeddedServer.applicationContext.createBean(HttpClient, embeddedServer.getURI())
+
+        when:
+        int max = 30
+        CountDownLatch latch = new CountDownLatch(max)
+
+        ExecutorService pool = Executors.newCachedThreadPool()
+        ConcurrentLinkedQueue<HttpStatus> responses = new ConcurrentLinkedQueue()
+        for (int i = 0; i < max; i++) {
+            pool.submit(() -> {
+                try {
+                    MultipartBody multipartBody = MultipartBody.builder()
+                            .addPart("myfile",
+                                    "largefile" * 1024)
+                            .build()
+                    HttpRequest request = HttpRequest.POST("/input-stream-test/hello", multipartBody)
+                            .contentType(MediaType.MULTIPART_FORM_DATA_TYPE)
+                    HttpResponse response = client.toBlocking()
+                            .exchange(request)
+                    responses.add(response.status())
+                    System.out.println(response.getStatus())
+                    System.out.println(response.getHeaders().asMap())
+
+                } catch (HttpClientResponseException e) {
+                    System.out.println(e.getStatus())
+                } catch (URISyntaxException e) {
+                    e.printStackTrace()
+                } finally {
+                    latch.countDown()
+                }
+
+            })
+        }
+        latch.await()
+
+        then:
+        responses.size() == 30
+        responses.every({ it == HttpStatus.OK})
+    }
+}
+
+@Controller("/input-stream-test")
+class PayloadInputStream {
+
+    @Inject
+    @Client("/")
+    private HttpClient httpClient
+
+    private String responsePayload = "<soap:Envelope xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\">\n" +
+            "   <soap:Body>\n" +
+            "      <ns2:getHelloWorldAsStringResponse xmlns:ns2=\"http://sample.soap.oracle/\">\n" +
+            "         <return>Hello World %s</return>\n" +
+            "      </ns2:getHelloWorldAsStringResponse>\n" +
+            "   </soap:Body>\n" +
+            "</soap:Envelope>"
+
+
+    @Post("/hello")
+    @Produces(MediaType.APPLICATION_JSON)
+    @Consumes(MediaType.ALL)
+    @ExecuteOn(TaskExecutors.IO)
+    MutableHttpResponse<String> stream(@Body @Nullable InputStream payload) throws IOException {
+
+        //blocking read on injected http client
+        HttpResponse<String> resp = httpClient.toBlocking().exchange(HttpRequest
+                .GET(URI.create("/input-stream-test/hello/other")), String.class)
+        System.out.println(resp.getBody(String.class).get())
+
+
+        byte[] body = payload.bytes
+        String b = new String(body)
+        int l = body.length
+
+        responsePayload = "{\n" +
+                "\t\"payload\" : {\n" +
+                "\t\t\"name\" : \"1542\"\n" +
+                "\t}\n" +
+                "}"
+        return HttpResponse.ok().body(responsePayload).contentType(MediaType.APPLICATION_JSON)
+    }
+
+    @Get("/hello/other")
+    String other() {
+        return "Some body content"
+    }
+}

inject/src/main/java/io/micronaut/context/BeanProvider.java

@@ -144,4 +144,17 @@ default void ifResolvable(@NonNull Consumer<T> consumer) {
         return (Argument) Argument.of(BeanProvider.class, Objects.requireNonNull(type, "Type cannot be null"));
     }
 
+    /**
+     * Allows selecting an alternative bean if the backing bean is not present.
+     * @param alternative The alternative, can be {@code null}
+     * @return The bean if present or else the supplied alternative
+     * @since 3.0.2
+     */
+    default @Nullable T orElse(@Nullable T alternative) {
+        if (isPresent()) {
+            return get();
+        } else {
+            return alternative;
+        }
+    }
 }