Android example source code file (BinderThreadPriorityTest.java)

This example Android source code file (BinderThreadPriorityTest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, androidtestcase, binderthreadprioritytest, can't, content, exception, file, ibinderthreadpriorityservice, interruptedexception, io, override, runtimeexception, serviceconnection, servicestub, string, tag, test, unknown, util, utilities

The BinderThreadPriorityTest.java Android example source code

/*
 * Copyright (C) 2010 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.
 */

package android.os;

import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.test.AndroidTestCase;
import android.test.suitebuilder.annotation.MediumTest;
import android.util.Log;

import java.io.File;
import java.io.IOException;

/**
 * Test whether Binder calls inherit thread priorities correctly.
 */
public class BinderThreadPriorityTest extends AndroidTestCase {
    private static final String TAG = "BinderThreadPriorityTest";
    private IBinderThreadPriorityService mService;
    private int mSavedPriority;

    private ServiceConnection mConnection = new ServiceConnection() {
        public void onServiceConnected(ComponentName name, IBinder service) {
            synchronized (BinderThreadPriorityTest.this) {
                mService = IBinderThreadPriorityService.Stub.asInterface(service);
                BinderThreadPriorityTest.this.notifyAll();
            }
        }

        public void onServiceDisconnected(ComponentName name) {
            mService = null;
        }
    };

    private static class ServiceStub extends IBinderThreadPriorityService.Stub {
        public int getThreadPriority() { fail(); return -999; }
        public String getThreadSchedulerGroup() { fail(); return null; }
        public void setPriorityAndCallBack(int p, IBinderThreadPriorityService cb) { fail(); }
        public void callBack(IBinderThreadPriorityService cb) { fail(); }
        private static void fail() { throw new RuntimeException("unimplemented"); }
    }

    @Override
    protected void setUp() throws Exception {
        super.setUp();

        getContext().bindService(
                new Intent(getContext(), BinderThreadPriorityService.class),
                mConnection, Context.BIND_AUTO_CREATE);

        synchronized (this) {
            if (mService == null) {
                try {
                    wait(30000);
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
                assertNotNull("Gave up waiting for BinderThreadPriorityService", mService);
            }
        }

        mSavedPriority = Process.getThreadPriority(Process.myTid());
        Process.setThreadPriority(mSavedPriority);  // To realign priority & cgroup, if needed
        assertEquals(expectedSchedulerGroup(mSavedPriority), getSchedulerGroup());
        Log.i(TAG, "Saved priority: " + mSavedPriority);
    }

    @Override
    protected void tearDown() throws Exception {
        // HACK -- see bug 2665914 -- setThreadPriority() doesn't always set the
        // scheduler group reliably unless we start out with background priority.
        Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
        Process.setThreadPriority(mSavedPriority);
        assertEquals(mSavedPriority, Process.getThreadPriority(Process.myTid()));
        assertEquals(expectedSchedulerGroup(mSavedPriority), getSchedulerGroup());

        getContext().unbindService(mConnection);
        super.tearDown();
    }

    public static String getSchedulerGroup() {
        String fn = "/proc/" + Process.myPid() + "/task/" + Process.myTid() + "/cgroup";
        try {
            String cgroup = FileUtils.readTextFile(new File(fn), 1024, null);
            for (String line : cgroup.split("\n")) {
                String fields[] = line.trim().split(":");
                    if (fields.length == 3 && fields[1].equals("cpu")) return fields[2];
            }
        } catch (IOException e) {
            Log.e(TAG, "Can't read: " + fn, e);
        }
        return null;  // Unknown
    }

    public static String expectedSchedulerGroup(int prio) {
        return prio < Process.THREAD_PRIORITY_BACKGROUND ? "/" : "/bg_non_interactive";
    }

    public void testPassPriorityToService() throws Exception {
        for (int prio = 19; prio >= -20; prio--) {
            Process.setThreadPriority(prio);

            // Local
            assertEquals(prio, Process.getThreadPriority(Process.myTid()));
            assertEquals(expectedSchedulerGroup(prio), getSchedulerGroup());

            // Remote
            assertEquals(prio, mService.getThreadPriority());
            assertEquals(expectedSchedulerGroup(prio), mService.getThreadSchedulerGroup());
        }
    }

    public void testCallBackFromServiceWithPriority() throws Exception {
        for (int prio = -20; prio <= 19; prio++) {
            final int expected = prio;
            mService.setPriorityAndCallBack(prio, new ServiceStub() {
                public void callBack(IBinderThreadPriorityService cb) {
                    assertEquals(expected, Process.getThreadPriority(Process.myTid()));
                    assertEquals(expectedSchedulerGroup(expected), getSchedulerGroup());
                }
            });

            assertEquals(mSavedPriority, Process.getThreadPriority(Process.myTid()));

            // BROKEN -- see bug 2665954 -- scheduler group doesn't get reset
            // properly after a back-call with a different priority.
            // assertEquals(expectedSchedulerGroup(mSavedPriority), getSchedulerGroup());
        }
    }
}