[MEXEC-mojohausGH-128] - <timeout> configuration parameter

Fixes mojohaus#128.

A new `<timeout>` configuration parameter (default: 0, which means
"none") allows to explicitly terminate a process running for longer that the given time in
minutes, and will fail the build.

Signed-off-by: Markus KARG <[email protected]>

src/it/projects/mexec-gh-128/invoker.properties

@@ -0,0 +1,3 @@
+invoker.goals = clean package
+invoker.buildResult = failure
+invoker.debug = true

src/it/projects/mexec-gh-128/pom.xml

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>org.codehaus.mojo.exec.it</groupId>
+    <artifactId>parent</artifactId>
+    <version>0.1</version>
+  </parent>
+
+  <artifactId>mexec-gh-128</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <version>@pom.version@</version>
+        <executions>
+          <execution>
+            <phase>process-classes</phase>
+            <goals>
+              <goal>exec</goal>
+            </goals>
+            <configuration>
+              <timeout>1000</timeout>
+              <executable>${JAVA_HOME}/bin/java</executable>
+              <arguments>
+                <argument>-cp</argument>
+                <argument>target/classes</argument>
+                <argument>Main</argument>
+              </arguments>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>

src/it/projects/mexec-gh-128/src/main/java/Main.java

@@ -0,0 +1,15 @@
+import java.io.FileWriter;
+import java.io.Writer;
+import java.net.URL;
+
+public class Main
+{
+    public static void main( String[] args ) throws Exception
+    {
+        /*
+         * Intentionally hangs for "very long" time to simulate a completely stuck executable,
+         * but let the time be so short that the IT would break "quickly" in any case.
+         */
+        Thread.sleep( 10000 );
+    }
+}

src/it/projects/mexec-gh-128/verify.groovy

@@ -0,0 +1,29 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.io.*
+import java.util.*
+
+t = new IntegrationBase()
+
+def buildLog = new File( basedir, "build.log" )
+
+t.checkExistenceAndContentOfAFile(buildLog, [
+  "[ERROR] Timeout. Process runs longer than 1000 ms."
+])

src/main/java/org/codehaus/mojo/exec/ExecMojo.java

@@ -46,6 +46,7 @@
 import org.apache.commons.exec.DefaultExecutor;
 import org.apache.commons.exec.ExecuteException;
 import org.apache.commons.exec.ExecuteResultHandler;
+import org.apache.commons.exec.ExecuteWatchdog;
 import org.apache.commons.exec.Executor;
 import org.apache.commons.exec.OS;
 import org.apache.commons.exec.ProcessDestroyer;
@@ -103,6 +104,21 @@ public class ExecMojo
     @Parameter( property = "exec.executable" )
     private String executable;
 
+    /**
+     * <p>
+     * Timeout in full milliseconds, default is {@code 0}.
+     * <p>
+     * <p>
+     * When set to a value larger than zero, the executable is forcefully
+     * terminated if it did not finish within this time, and the build will
+     * fail.
+     * </p>
+     *
+     * @since 3.0.0
+     */
+    @Parameter( property = "exec.timeout", defaultValue = "0" )
+    private int timeout;
+
     /**
      * <p>
      * The toolchain. If omitted, <code>"jdk"</code> is assumed.
@@ -148,7 +164,7 @@ public class ExecMojo
      */
     @Parameter( readonly = true, required = true, defaultValue = "${basedir}" )
     private File basedir;
-    
+
     /**
      * @since 3.0.0
      */
@@ -226,7 +242,7 @@ public class ExecMojo
     private boolean asyncDestroyOnShutdown = true;
 
     public static final String CLASSPATH_TOKEN = "%classpath";
-    
+
     public static final String MODULEPATH_TOKEN = "%modulepath";
 
     /**
@@ -293,6 +309,10 @@ else if ( !StringUtils.isEmpty( argsProp ) )
             commandLine.addArguments( args, false );
 
             Executor exec = new DefaultExecutor();
+            if ( this.timeout > 0 )
+            {
+                exec.setWatchdog( new ExecuteWatchdog( this.timeout ) );
+            }
             exec.setWorkingDirectory( workingDirectory );
             fillSuccessCodes( exec );
 
@@ -334,8 +354,17 @@ else if ( !StringUtils.isEmpty( argsProp ) )
             }
             catch ( ExecuteException e )
             {
-                getLog().error( "Command execution failed.", e );
-                throw new MojoExecutionException( "Command execution failed.", e );
+                if ( exec.getWatchdog() != null && exec.getWatchdog().killedProcess() )
+                {
+                    final String message = "Timeout. Process runs longer than " + this.timeout + " ms.";
+                    getLog().error( message );
+                    throw new MojoExecutionException( message, e );
+                }
+                else
+                {
+                    getLog().error( "Command execution failed.", e );
+                    throw new MojoExecutionException( "Command execution failed.", e );
+                }
             }
             catch ( IOException e )
             {
@@ -471,7 +500,7 @@ private void handleArguments( List<String> commandArguments )
         throws MojoExecutionException, IOException
     {
         String specialArg = null;
-        
+
         for ( int i = 0; i < arguments.size(); i++ )
         {
             Object argument = arguments.get( i );
@@ -972,12 +1001,12 @@ private File createJar( List<String> classPath, String mainClass )
 
         return file;
     }
-    
+
     private void createArgFile( String filePath, List<String> lines )
         throws IOException
     {
         final String EOL = System.getProperty( "line.separator", "\\n" );
-        
+
         FileWriter writer = null;
         try
         {