ProcessUtil cleanup

- possible resource leak closed
- file content read uses now commons-lang FileUtils
- Added unit tests

utils/src/com/cloud/utils/ProcessUtil.java

@@ -16,24 +16,20 @@
 // under the License.
 package com.cloud.utils;
 
-import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileInputStream;
-import java.io.FileOutputStream;
 import java.io.IOException;
-import java.io.InputStreamReader;
+import java.util.Properties;
 
 import javax.naming.ConfigurationException;
 
+import org.apache.commons.io.FileUtils;
 import org.apache.log4j.Logger;
 
-import com.cloud.utils.PropertiesUtil;
 import com.cloud.utils.exception.CloudRuntimeException;
 import com.cloud.utils.script.OutputInterpreter;
 import com.cloud.utils.script.Script;
 
-import java.util.Properties;
-
 public class ProcessUtil {
     private static final Logger s_logger = Logger.getLogger(ProcessUtil.class.getName());
 
@@ -68,10 +64,8 @@ public class ProcessUtil {
 	                throw new ConfigurationException("Unable to write to " + pidFile.getAbsolutePath() + ".  Are you sure you're running as root?");
 	            }
 
-	            final FileInputStream is = new FileInputStream(pidFile);
+	            final String pidLine = FileUtils.readFileToString(pidFile).trim();
-	            final BufferedReader reader = new BufferedReader(new InputStreamReader(is));
+	            if (pidLine.isEmpty()) {
-	            final String pidLine = reader.readLine();
-	            if (pidLine == null) {
 	                throw new ConfigurationException("Java process is being started twice.  If this is not true, remove " + pidFile.getAbsolutePath());
 	            }
 	            try {
@@ -101,9 +95,7 @@ public class ProcessUtil {
 	
 	        final String pid = parser.getLine();
 	
-	        final FileOutputStream strm = new FileOutputStream(pidFile);
+	        FileUtils.writeStringToFile(pidFile, pid + "\n");
-	        strm.write((pid + "\n").getBytes());
-	        strm.close();
 	    } catch (final IOException e) {
 	        throw new CloudRuntimeException("Unable to create the " + pidFile.getAbsolutePath() + ".  Are you running as root?", e);
 	    }

utils/test/com/cloud/utils/ProcessUtilTest.java

@@ -0,0 +1,57 @@
+package com.cloud.utils;
+
+import java.io.File;
+import java.io.IOException;
+
+import javax.naming.ConfigurationException;
+
+import junit.framework.Assert;
+
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.lang.SystemUtils;
+import org.junit.After;
+import org.junit.Assume;
+import org.junit.Before;
+import org.junit.Test;
+
+public class ProcessUtilTest {
+
+    File pidFile;
+
+    @Before
+    public void setup() throws IOException {
+        pidFile = File.createTempFile("test", ".pid");
+    }
+
+    @After
+    public void cleanup() {
+        FileUtils.deleteQuietly(pidFile);
+    }
+
+    @Test
+    public void pidCheck() throws ConfigurationException, IOException {
+        Assume.assumeTrue(SystemUtils.IS_OS_LINUX);
+        FileUtils.writeStringToFile(pidFile, "123456\n");
+        ProcessUtil.pidCheck(pidFile.getParent(), pidFile.getName());
+        String pidStr = FileUtils.readFileToString(pidFile);
+        Assert.assertFalse("pid can not be blank", pidStr.isEmpty());
+        int pid = Integer.parseInt(pidStr.trim());
+        int maxPid = Integer.parseInt(FileUtils.readFileToString(new File("/proc/sys/kernel/pid_max")).trim());
+        Assert.assertTrue(pid <= maxPid);
+    }
+
+    @Test(expected = ConfigurationException.class)
+    public void pidCheckBadPid() throws ConfigurationException, IOException {
+        Assume.assumeTrue(SystemUtils.IS_OS_LINUX);
+        FileUtils.writeStringToFile(pidFile, "intentionally not number");
+        ProcessUtil.pidCheck(pidFile.getParent(), pidFile.getName());
+    }
+
+    @Test(expected = ConfigurationException.class)
+    public void pidCheckEmptyPid() throws ConfigurationException, IOException {
+        Assume.assumeTrue(SystemUtils.IS_OS_LINUX);
+        FileUtils.writeStringToFile(pidFile, "intentionally not number");
+        ProcessUtil.pidCheck(pidFile.getParent(), pidFile.getName());
+    }
+
+}