[Backport] 8229209: [TESTBUG] test for cross-process JFR event streaming

Summary:

Test Plan: jdk/jfr

Reviewed-by: yuleil

Issue: https://github.com/alibaba/dragonwell8/issues/112

test/jdk/jfr/api/consumer/streaming/TestCrossProcessStreaming.java

+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.jfr.api.consumer.streaming;
+
+import static jdk.test.lib.Asserts.assertTrue;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import com.sun.tools.attach.VirtualMachine;
+import jdk.jfr.Event;
+import jdk.jfr.Recording;
+import jdk.jfr.consumer.EventStream;
+import jdk.test.lib.Asserts;
+import jdk.test.lib.process.ProcessTools;
+
+/**
+ * @test
+ * @summary Test scenario where JFR event producer is in a different process
+ *          with respect to the JFR event stream consumer.
+ * @key jfr
+ * @library /lib /
+ * @modules jdk.attach
+ *          jdk.jfr
+ * @run main jdk.jfr.api.consumer.streaming.TestCrossProcessStreaming
+ */
+
+public class TestCrossProcessStreaming {
+    static String MAIN_STARTED_TOKEN = "MAIN_STARTED";
+
+    public static class TestEvent extends Event {
+    }
+
+    public static class ResultEvent extends Event {
+        int nrOfEventsProduced;
+    }
+
+    public static class EventProducer {
+        public static void main(String... args) throws Exception {
+            Path pidPath = Paths.get(args[1]);
+            writeString(pidPath, ProcessTools.getProcessId() + "@");
+
+            CrossProcessSynchronizer sync = new CrossProcessSynchronizer();
+            log(MAIN_STARTED_TOKEN);
+
+            long pid = ProcessTools.getProcessId();
+            int nrOfEvents = 0;
+            boolean exitRequested = false;
+            while (!exitRequested) {
+                TestEvent e = new TestEvent();
+                e.commit();
+                nrOfEvents++;
+                if (nrOfEvents % 1000 == 0) {
+                    Thread.sleep(100);
+                    exitRequested = CrossProcessSynchronizer.exitRequested(pid);
+                }
+            }
+
+            ResultEvent re = new ResultEvent();
+            re.nrOfEventsProduced = nrOfEvents;
+            re.commit();
+
+            log("Number of TestEvents generated: " + nrOfEvents);
+        }
+    }
+
+
+    static class CrossProcessSynchronizer {
+        static void requestExit(long pid) throws Exception {
+            Files.createFile(file(pid));
+       }
+
+        static boolean exitRequested(long pid) throws Exception {
+            return Files.exists(file(pid));
+        }
+
+        static Path file(long pid) {
+            return Paths.get(".", "exit-requested-" + pid);
+        }
+    }
+
+
+    static class ConsumedEvents {
+        AtomicInteger total = new AtomicInteger(0);
+        AtomicInteger whileProducerAlive = new AtomicInteger(0);
+        AtomicInteger produced = new AtomicInteger(-1);
+    }
+
+    private static String readString(Path path) throws IOException {
+        try (InputStream in = new FileInputStream(path.toFile())) {
+            byte[] bytes = new byte[32];
+            int length = in.read(bytes);
+            assertTrue(length < bytes.length, "bytes array to small");
+            if (length == -1) {
+                return null;
+            }
+            return new String(bytes, 0, length);
+        }
+    }
+
+    private static void writeString(Path path, String content) throws IOException {
+        try (OutputStream out = new FileOutputStream(path.toFile())) {
+            out.write(content.getBytes());
+        }
+    }
+
+    public static void main(String... args) throws Exception {
+        Process p = startProducerProcess("normal");
+        String repo = getJfrRepository(p);
+
+        ConsumedEvents ce = consumeEvents(p, repo);
+
+        p.waitFor();
+        Asserts.assertEquals(p.exitValue(), 0,
+                             "Process exited abnormally, exitValue = " + p.exitValue());
+
+        Asserts.assertEquals(ce.total.get(), ce.produced.get(), "Some events were lost");
+
+        // Expected that some portion of events emitted by the producer are delivered
+        // to the consumer while producer is still alive, at least one event for certain.
+        Asserts.assertLTE(1, ce.whileProducerAlive.get(),
+                           "Too few events are delivered while producer is alive");
+    }
+
+    private static long pid;
+
+    static Process startProducerProcess(String extraParam) throws Exception {
+        Path pidPath = Paths.get("pid-" + System.currentTimeMillis()).toAbsolutePath();
+        ProcessBuilder pb =
+            ProcessTools.createJavaProcessBuilder(false,
+                                                  "-XX:StartFlightRecording",
+                                                  EventProducer.class.getName(),
+                                                  extraParam,
+                                                  pidPath.toString());
+        Process p = ProcessTools.startProcess("Event-Producer", pb,
+                                              line -> line.equals(MAIN_STARTED_TOKEN),
+                                              0, TimeUnit.SECONDS);
+
+        do {
+            Thread.sleep(10);
+        } while (!pidPath.toFile().exists());
+
+        String pidStr;
+        do {
+            pidStr = readString(pidPath);
+        } while (pidStr == null || !pidStr.endsWith("@"));
+
+        pid = Long.valueOf(pidStr.substring(0, pidStr.length()-1));
+        return p;
+    }
+
+    static String getJfrRepository(Process p) throws Exception {
+        String repo = null;
+
+        // It may take little bit of time for the observed process to set the property after
+        // the process starts, therefore read the property in a loop.
+        while (repo == null) {
+            VirtualMachine vm = VirtualMachine.attach(String.valueOf(pid));
+            repo = vm.getSystemProperties().getProperty("jdk.jfr.repository");
+            vm.detach();
+        }
+
+        log("JFR repository = " + repo);
+        return repo;
+    }
+
+    static ConsumedEvents consumeEvents(Process p, String repo) throws Exception {
+        ConsumedEvents result = new ConsumedEvents();
+
+        // wait for couple of JFR stream flushes before concluding the test
+        CountDownLatch flushed = new CountDownLatch(2);
+
+        // consume events produced by another process via event stream
+        try (EventStream es = EventStream.openRepository(Paths.get(repo))) {
+                es.onEvent(TestEvent.class.getName(),
+                           e -> {
+                               result.total.incrementAndGet();
+                               if (p.isAlive()) {
+                                   result.whileProducerAlive.incrementAndGet();
+                               }
+                           });
+
+                es.onEvent(ResultEvent.class.getName(),
+                           e -> result.produced.set(e.getInt("nrOfEventsProduced")));
+
+                es.onFlush( () -> flushed.countDown() );
+
+                // Setting start time to the beginning of the Epoch is a good way to start
+                // reading the stream from the very beginning.
+                es.setStartTime(Instant.EPOCH);
+                es.startAsync();
+
+                // await for certain number of flush events before concluding the test case
+                flushed.await();
+                CrossProcessSynchronizer.requestExit(pid);
+
+                es.awaitTermination();
+            }
+
+        return result;
+    }
+
+    private static final void log(String msg) {
+        System.out.println(msg);
+    }
+}