| /* |
| * Copyright (C) 2016 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.util.Arrays; |
| import java.util.concurrent.CountDownLatch; |
| |
| public class Main { |
| public static void main(String[] args) throws Exception { |
| System.loadLibrary(args[1]); |
| |
| doTest(); |
| doTestOtherThreadWait(); |
| doTestOtherThreadBusyLoop(); |
| } |
| |
| public static void doTest() throws Exception { |
| System.out.println("###################"); |
| System.out.println("### Same thread ###"); |
| System.out.println("###################"); |
| System.out.println("From top"); |
| Recurse.foo(4, 0, 25, null); |
| Recurse.foo(4, 1, 25, null); |
| Recurse.foo(4, 0, 5, null); |
| Recurse.foo(4, 2, 5, null); |
| |
| System.out.println("From bottom"); |
| Recurse.foo(4, -1, 25, null); |
| Recurse.foo(4, -5, 5, null); |
| Recurse.foo(4, -7, 5, null); |
| } |
| |
| public static void doTestOtherThreadWait() throws Exception { |
| System.out.println(); |
| System.out.println("################################"); |
| System.out.println("### Other thread (suspended) ###"); |
| System.out.println("################################"); |
| final ControlData data = new ControlData(); |
| data.waitFor = new Object(); |
| Thread t = new Thread() { |
| public void run() { |
| Recurse.foo(4, 0, 0, data); |
| } |
| }; |
| t.start(); |
| data.reached.await(); |
| Thread.yield(); |
| Thread.sleep(500); // A little bit of time... |
| |
| System.out.println("From top"); |
| print(t, 0, 25); |
| print(t, 1, 25); |
| print(t, 0, 5); |
| print(t, 2, 5); |
| |
| System.out.println("From bottom"); |
| print(t, -1, 25); |
| print(t, -5, 5); |
| print(t, -7, 5); |
| |
| // Let the thread make progress and die. |
| synchronized(data.waitFor) { |
| data.waitFor.notifyAll(); |
| } |
| t.join(); |
| } |
| |
| public static void doTestOtherThreadBusyLoop() throws Exception { |
| System.out.println(); |
| System.out.println("###########################"); |
| System.out.println("### Other thread (live) ###"); |
| System.out.println("###########################"); |
| final ControlData data = new ControlData(); |
| Thread t = new Thread() { |
| public void run() { |
| Recurse.foo(4, 0, 0, data); |
| } |
| }; |
| t.start(); |
| data.reached.await(); |
| Thread.yield(); |
| Thread.sleep(500); // A little bit of time... |
| |
| System.out.println("From top"); |
| print(t, 0, 25); |
| print(t, 1, 25); |
| print(t, 0, 5); |
| print(t, 2, 5); |
| |
| System.out.println("From bottom"); |
| print(t, -1, 25); |
| print(t, -5, 5); |
| print(t, -7, 5); |
| |
| // Let the thread stop looping and die. |
| data.stop = true; |
| t.join(); |
| } |
| |
| public static void print(String[] stack) { |
| System.out.println("---------"); |
| for (int i = 0; i < stack.length; i += 2) { |
| System.out.print(' '); |
| System.out.print(stack[i]); |
| System.out.print(' '); |
| System.out.println(stack[i + 1]); |
| } |
| } |
| |
| public static void print(Thread t, int start, int max) { |
| print(getStackTrace(t, start, max)); |
| } |
| |
| // Wrap generated stack traces into a class to separate them nicely. |
| public static class Recurse { |
| |
| public static int foo(int x, int start, int max, ControlData data) { |
| bar(x, start, max, data); |
| return 0; |
| } |
| |
| private static long bar(int x, int start, int max, ControlData data) { |
| baz(x, start, max, data); |
| return 0; |
| } |
| |
| private static Object baz(int x, int start, int max, ControlData data) { |
| if (x == 0) { |
| printOrWait(start, max, data); |
| } else { |
| foo(x - 1, start, max, data); |
| } |
| return null; |
| } |
| |
| private static void printOrWait(int start, int max, ControlData data) { |
| if (data == null) { |
| print(Thread.currentThread(), start, max); |
| } else { |
| if (data.waitFor != null) { |
| synchronized (data.waitFor) { |
| data.reached.countDown(); |
| try { |
| data.waitFor.wait(); // Use wait() as it doesn't have a "hidden" Java call-graph. |
| } catch (Throwable t) { |
| throw new RuntimeException(t); |
| } |
| } |
| } else { |
| data.reached.countDown(); |
| while (!data.stop) { |
| // Busy-loop. |
| } |
| } |
| } |
| } |
| } |
| |
| public static class ControlData { |
| CountDownLatch reached = new CountDownLatch(1); |
| Object waitFor = null; |
| volatile boolean stop = false; |
| } |
| |
| public static native String[] getStackTrace(Thread thread, int start, int max); |
| } |