1 files changed, 83 insertions, 0 deletions
diff --git a/test/2044-get-stack-traces/src/Main.java b/test/2044-get-stack-traces/src/Main.java
new file mode 100644
index 0000000000..d17e7c18f4
--- /dev/null
+++ b/test/2044-get-stack-traces/src/Main.java
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.lang.ref.Reference;
+import java.lang.ref.WeakReference;
+import java.lang.ref.SoftReference;
+import java.math.BigInteger;
+import java.util.ArrayList;
+
+/**
+ * We construct a main thread and worker threads, each retrieving stack traces
+ * from the other. Since there are multiple workers, we may get a large number
+ * of simultaneous stack trace attempts.
+ */
+public class Main {
+    static final int NUM_THREADS = 5;
+    static Thread mainThread;
+    static volatile boolean pleaseStop = false;
+
+    private static void getTrace(Thread t) {
+      StackTraceElement trace[] = t.getStackTrace();
+      if (trace.length < 1 || trace.length > 20) {
+        System.out.println("Stack trace for " + t.getName() + " has size " + trace.length);
+        for (StackTraceElement e : trace) {
+          System.out.println(e.toString());
+        }
+      }
+    }
+
+    /**
+     * Repeatedly get and minimally check stack trace of main thread.
+     */
+    static Runnable traceGetter = new Runnable() {
+        public void run() {
+          System.out.println("Starting helper");
+          while (!pleaseStop) {
+            getTrace(mainThread);
+          }
+        }
+    };
+
+    public static void main(String[] args) throws Exception {
+        System.out.println("Starting");
+        Thread[] t = new Thread[NUM_THREADS];
+        mainThread = Thread.currentThread();
+        for (int i = 0; i < NUM_THREADS; ++i) {
+          t[i] = new Thread(traceGetter);
+          t[i].start();
+        }
+        try {
+          Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            System.out.println("Unexpectedly interrupted");
+        }
+        for (int i = 0; i < NUM_THREADS; ++i) {
+          getTrace(t[i]);
+        }
+        System.out.println("Finished worker stack traces");
+        long now = System.currentTimeMillis();
+        while (System.currentTimeMillis() - now < 2000) {
+          try {
+            Thread.sleep(1);
+          } catch (InterruptedException e) {
+            System.out.println("Unexpectedly interrupted");
+          }
+        }
+        pleaseStop = true;
+        System.out.println("Finished");
+    }
+}