gemfire-core/src/test/java/com/gemstone/gemfire/internal/process/LocalProcessLauncherJUnitTest.java

/*=========================================================================
 * Copyright (c) 2010-2014 Pivotal Software, Inc. All Rights Reserved.
 * This product is protected by U.S. and international copyright
 * and intellectual property laws. Pivotal products are covered by
 * one or more patents listed at http://www.pivotal.io/patents.
 *=========================================================================
 */
package com.gemstone.gemfire.internal.process;

import static org.junit.Assert.*;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;

import org.junit.Before;
import org.junit.Test;
import org.junit.experimental.categories.Category;

import com.gemstone.gemfire.internal.OSProcess;
import com.gemstone.gemfire.internal.process.LocalProcessLauncher;
import com.gemstone.gemfire.test.junit.categories.UnitTest;

/**
 * Unit tests for ProcessLauncher.
 * 
 * @author Kirk Lund
 * @since 7.0
 */
@Category(UnitTest.class)
public class LocalProcessLauncherJUnitTest {

  @Before
  public void createDirectory() throws Exception {
    new File(getClass().getSimpleName()).mkdir();
  }
  
  @Test
  public void testPidAccuracy() throws PidUnavailableException {
    int pid = ProcessUtils.identifyPid();
    assertTrue(pid > 0);
    int osProcessPid = OSProcess.getId();
    if (osProcessPid > 0) {
      assertEquals(OSProcess.getId(), pid);
    } else {
      // not much to test if OSProcess native code is unusable
    }
  }
  
  @Test
  public void testPidFileIsCreated() throws Exception {
    final File pidFile = new File(getClass().getSimpleName() 
        + File.separator + "testPidFileIsCreated.pid");
    assertFalse(pidFile.exists());
    new LocalProcessLauncher(pidFile, false);
    assertTrue(pidFile.exists());
  }
  
  @Test
  public void testPidFileContainsPid() throws Exception {
    final File pidFile = new File(getClass().getSimpleName() 
        + File.separator + "testPidFileContainsPid.pid");
    final LocalProcessLauncher launcher = new LocalProcessLauncher(pidFile, false);
    assertNotNull(launcher);
    assertTrue(pidFile.exists());
    
    final FileReader fr = new FileReader(pidFile);
    final BufferedReader br = new BufferedReader(fr);
    final int pid = Integer.parseInt(br.readLine());
    br.close();
    
    assertTrue(pid > 0);
    assertEquals(launcher.getPid(), pid);
    assertEquals(ProcessUtils.identifyPid(), pid);
  }
  
  @Test
  public void testPidFileIsCleanedUp() throws Exception {
    final File pidFile = new File(getClass().getSimpleName() 
        + File.separator + "testPidFileIsCleanedUp.pid");
    final LocalProcessLauncher launcher = new LocalProcessLauncher(pidFile, false);
    assertTrue(pidFile.exists());
    launcher.close(); // TODO: launch an external JVM and then close it nicely
    assertFalse(pidFile.exists());
  }
  
  @Test
  public void testExistingPidFileThrows() throws Exception {
    final File pidFile = new File(getClass().getSimpleName() 
        + File.separator + "testExistingPidFileThrows.pid");
    assertTrue(pidFile.createNewFile());
    assertTrue(pidFile.exists());
    
    final FileWriter writer = new FileWriter(pidFile);
    // use a read pid that exists
    writer.write(String.valueOf(ProcessUtils.identifyPid()));
    writer.close();

    try {
      new LocalProcessLauncher(pidFile, false);
      fail("LocalProcessLauncher should have thrown FileAlreadyExistsException");
    } catch (FileAlreadyExistsException e) {
      // passed
    }
  }

  @Test
  public void testStalePidFileIsReplaced() throws Exception {
    final File pidFile = new File(getClass().getSimpleName() 
        + File.separator + "testStalePidFileIsReplaced.pid");
    assertTrue(pidFile.createNewFile());
    assertTrue(pidFile.exists());
    
    final FileWriter writer = new FileWriter(pidFile);
    writer.write(String.valueOf(Integer.MAX_VALUE));
    writer.close();

    try {
      new LocalProcessLauncher(pidFile, false);
    } catch (FileAlreadyExistsException e) {
      fail("LocalProcessLauncher should not have thrown FileAlreadyExistsException");
    }

    final FileReader fr = new FileReader(pidFile);
    final BufferedReader br = new BufferedReader(fr);
    final int pid = Integer.parseInt(br.readLine());
    br.close();

    assertTrue(pid > 0);
    assertEquals(ProcessUtils.identifyPid(), pid);
  }

  @Test
  public void testForceReplacesExistingPidFile() throws Exception {
    assertTrue("testForceReplacesExistingPidFile is broken if PID == Integer.MAX_VALUE", 
        ProcessUtils.identifyPid() != Integer.MAX_VALUE);
    
    final File pidFile = new File(getClass().getSimpleName() 
        + File.separator + "testForceReplacesExistingPidFile.pid");
    assertTrue(pidFile.createNewFile());
    assertTrue(pidFile.exists());
    
    final FileWriter writer = new FileWriter(pidFile);
    writer.write(String.valueOf(Integer.MAX_VALUE));
    writer.close();
    
    try {
      new LocalProcessLauncher(pidFile, true);
    } catch (FileAlreadyExistsException e) {
      fail("LocalProcessLauncher should not have thrown FileAlreadyExistsException");
    }

    final FileReader fr = new FileReader(pidFile);
    final BufferedReader br = new BufferedReader(fr);
    final int pid = Integer.parseInt(br.readLine());
    br.close();

    assertTrue(pid > 0);
    assertEquals(ProcessUtils.identifyPid(), pid);
  }
  
  @Test
  public void testPidUnavailableThrows() {
    final String name = "Name without PID";
    try {
      ProcessUtils.identifyPid(name);
      fail("PidUnavailableException should have been thrown for " + name);
    } catch (PidUnavailableException e) {
     // passed
    }
  }
}