blob: 50e8c098de4a188a8b492ab12df604a839798a7e [file] [log] [blame]
/*
* Copyright (C) 2014 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.reflect.Field;
import java.util.Map;
public class Main implements Runnable {
static final int NUMBER_OF_THREADS = 5;
static final int TOTAL_OPERATIONS = 900;
public static void main(String[] args) throws Exception {
final Thread[] threads = new Thread[NUMBER_OF_THREADS];
for (int t = 0; t < threads.length; t++) {
threads[t] = new Thread(new Main());
threads[t].start();
}
for (Thread t : threads) {
t.join();
}
// Do this test after the other part to leave some time for the heap task daemon to start
// up.
test_getStackTraces();
System.out.println("Finishing");
}
static Thread getHeapTaskDaemon() throws Exception {
Field f = ThreadGroup.class.getDeclaredField("systemThreadGroup");
f.setAccessible(true);
ThreadGroup systemThreadGroup = (ThreadGroup) f.get(null);
while (true) {
int activeCount = systemThreadGroup.activeCount();
Thread[] array = new Thread[activeCount];
systemThreadGroup.enumerate(array);
for (Thread thread : array) {
if (thread.getName().equals("HeapTaskDaemon") &&
thread.getState() != Thread.State.NEW) {
return thread;
}
}
// Yield to eventually get the daemon started.
Thread.sleep(10);
}
}
static void test_getStackTraces() throws Exception {
Thread heapDaemon = getHeapTaskDaemon();
// Force a GC to ensure the daemon truly started.
Runtime.getRuntime().gc();
// Check all the current threads for positive IDs.
Map<Thread, StackTraceElement[]> map = Thread.getAllStackTraces();
for (Map.Entry<Thread, StackTraceElement[]> pair : map.entrySet()) {
Thread thread = pair.getKey();
// Expect empty stack trace since we do not support suspending the GC thread for
// obtaining stack traces. See b/28261069.
if (thread == heapDaemon) {
System.out.println(thread.getName() + " depth " + pair.getValue().length);
}
}
}
public void test_getId() {
if (Thread.currentThread().getId() <= 0) {
System.out.println("current thread's ID is not positive");
}
// Check all the current threads for positive IDs.
Map<Thread, StackTraceElement[]> stMap = Thread.getAllStackTraces();
for (Thread thread : stMap.keySet()) {
if (thread.getId() <= 0) {
System.out.println("thread's ID is not positive: " + thread.getName());
}
}
}
public void run() {
for (int i = 0; i < TOTAL_OPERATIONS; ++i) {
test_getId();
}
}
}