Changeset 31640 for main/trunk/greenstone3/src

Timestamp:

2017-05-01T20:26:27+12:00 (7 years ago)

Author:

ak19

Message:

Porting across changes made to GLI's SafeProcess: 1. correct interrupt handling for when a process is cancelled; 2. Process object is now a member var; 3. Better way of swapping btw logging with logger in GS3 code versus in GLI which can use System.err or DebugStream; 4. Static helper methods including logging methods, and processRunning method ported from GLI's GShell.

File:

• main/trunk/greenstone3/src/java/org/greenstone/util/SafeProcess.java (modified) (41 diffs)

main/trunk/greenstone3/src/java/org/greenstone/util/SafeProcess.java

@@ -10 +10 @@
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
-
 import java.util.Arrays;
 
 import org.apache.log4j.*;
+
+//import org.greenstone.gatherer.DebugStream;
 
 // Use this class to run a Java Process. It follows the good and safe practices at
@@ -20 +21 @@
 
 public class SafeProcess {
-    
+    //public static int DEBUG = 0;
+
     public static final int STDERR = 0;
     public static final int STDOUT = 1;
-    public static final int STDIN = 2;    
+    public static final int STDIN = 2;
+
+    // charset for reading process stderr and stdout streams
+    //public static final String UTF8 = "UTF-8";    
 
     static Logger logger = Logger.getLogger(org.greenstone.util.SafeProcess.class.getName());
@@ -33 +38 @@
     private File dir = null;
     private String inputStr = null;
+    private Process process = null;
 
     // output from running SafeProcess.runProcess()
@@ -38 +44 @@
     private String errorStr = "";
     private int exitValue = -1;
+    //private String charset = null;
 
     // allow callers to process exceptions of the main process thread if they want
@@ -74 +81 @@
     public int getExitValue() { return exitValue; }
 
-    
+    //public void setStreamCharSet(String charset) { this.charset = charset; } 
+
     // set any string to send as input to the process spawned by SafeProcess
     public void setInputString(String sendStr) {
@@ -99 +107 @@
     
     if(this.command != null) {
+        log("SafeProcess running: " + command);
         prcs = rt.exec(this.command);
     }
@@ -104 +113 @@
         
         // http://stackoverflow.com/questions/5283444/convert-array-of-strings-into-a-string-in-java
-        logger.info("SafeProcess running: " + Arrays.toString(command_args));
-        //System.err.println("SafeProcess running: " + Arrays.toString(command_args));
+        log("SafeProcess running: " + Arrays.toString(command_args));
         
         if(this.envp == null) { 
@@ -112 +120 @@
         
         if(this.dir == null) {
-            ///logger.info("\twith: " + Arrays.toString(this.envp));
-            ///System.err.println("\twith: " + Arrays.toString(this.envp));
+            //log("\twith: " + Arrays.toString(this.envp));
             prcs = rt.exec(this.command_args, this.envp);
         } else {
-            ///logger.info("\tfrom directory: " + this.dir);
-            ///logger.info("\twith: " + Arrays.toString(this.envp));
-            ///System.err.println("\tfrom directory: " + this.dir);
-            ///System.err.println("\twith: " + Arrays.toString(this.envp));
-            prcs = rt.exec(this.command_args, this.envp, this.dir);
+            //log("\tfrom directory: " + this.dir);
+            //log("\twith: " + Arrays.toString(this.envp));         
+            prcs = rt.exec(this.command_args, this.envp, this.dir);
         }
         }
@@ -129 +134 @@
 
     // Copied from gli's gui/FormatConversionDialog.java
-    private int waitForWithStreams(Process prcs,
-                   SafeProcess.OutputStreamGobbler inputGobbler,
+    private int waitForWithStreams(SafeProcess.OutputStreamGobbler inputGobbler,
                    SafeProcess.InputStreamGobbler outputGobbler,
                    SafeProcess.InputStreamGobbler errorGobbler)
@@ -136 +140 @@
     {
 
-            // kick off the stream gobblers
-            inputGobbler.start();
-            errorGobbler.start();
-            outputGobbler.start();
-
-            // any error???
-            this.exitValue = prcs.waitFor(); // can throw an InterruptedException if process did not terminate
-
-            ///logger.info("Process exitValue: " + exitValue); 
-        ///System.err.println("Process exitValue: " + exitValue); 
-
+    
+    // kick off the stream gobblers
+    inputGobbler.start();
+    errorGobbler.start();
+    outputGobbler.start();
+    
+    // any error???
+    try {
+        this.exitValue = process.waitFor(); // can throw an InterruptedException if process did not terminate
+    } catch(InterruptedException ie) {
+        log("*** Process interrupted (InterruptedException). Expected to be a Cancel operation.");
+            // don't print stacktrace: an interrupt here is not an error, it's expected to be a cancel action
+        if(exceptionHandler != null) {      
+        exceptionHandler.gotException(ie);
+        }           
+        
+        // propagate interrupts to worker threads here
+        // unless the interrupt emanated from any of them in any join(),
+        // which will be caught by caller's catch on InterruptedException.
+        // Only if the thread that SafeProcess runs in was interrupted
+        // should we propagate the interrupt to the worker threads.
+        // http://stackoverflow.com/questions/2126997/who-is-calling-the-java-thread-interrupt-method-if-im-not
+        // "I know that in JCiP it is mentioned that you should never interrupt threads you do not own"
+        // But SafeProcess owns the worker threads, so it has every right to interrupt them
+        // Also read http://stackoverflow.com/questions/13623445/future-cancel-method-is-not-working?noredirect=1&lq=1
+        
+        // http://stackoverflow.com/questions/3976344/handling-interruptedexception-in-java
+        // http://stackoverflow.com/questions/4906799/why-invoke-thread-currentthread-interrupt-when-catch-any-interruptexception
+        // "Only code that implements a thread's interruption policy may swallow an interruption request. General-purpose task and library code should never swallow interruption requests."
+        // Does that mean that since this code implements this thread's interruption policy, it's ok
+        // to swallow the interrupt this time and not let it propagate by commenting out the next line?
+        //Thread.currentThread().interrupt(); // re-interrupt the thread
+
+        inputGobbler.interrupt();
+        errorGobbler.interrupt();
+        outputGobbler.interrupt();
+
+        // even after the interrupts, we want to proceed to calling join() on all the worker threads
+        // in order to wait for each of them to die before attempting to destroy the process if it
+        // still hasn't terminated after all that.
+    } finally {     
+        
+        //log("Process exitValue: " + exitValue);
+        
         // From the comments of 
         // http://www.javaworld.com/article/2071275/core-java/when-runtime-exec---won-t.html?page=2
@@ -152 +189 @@
         // if there's no waiting for the threads, call join() on each Thread (StreamGobbler) object.
         // From Thread API: join() "Waits for this thread (the thread join() is invoked on) to die."
+        
+        // Wait for each of the threads to die, before attempting to destroy the process
+        // Any of these can throw InterruptedExceptions too
+        // and will be processed by the calling function's catch on InterruptedException.
+        // However, no one besides us will interrupting these threads I think...
+        // and we won't be throwing the InterruptedException from within the threads...
+        // So if any streamgobbler.join() call throws an InterruptedException, that would be unexpected
+
         outputGobbler.join(); 
         errorGobbler.join();
-        inputGobbler.join(); 
-        
-
-        // set the variables the code that created a SafeProcess object may want to inspect
+        inputGobbler.join();
+        
+        
+        // set the variables that the code which created a SafeProcess object may want to inspect
         this.outputStr = outputGobbler.getOutput();
         this.errorStr = errorGobbler.getOutput();
@@ -163 +208 @@
         // Since we didn't have an exception, process should have terminated now (waitFor blocks until then)
         // Set process to null so we don't forcibly terminate it below with process.destroy()
-        prcs = null;
-
-        return this.exitValue;
-    }
-
+        this.process = null;        
+    }
+
+    // Don't return from finally, it's considered an abrupt completion and exceptions are lost, see
+    // http://stackoverflow.com/questions/18205493/can-we-use-return-in-finally-block
+    return this.exitValue;
+    }
+
+
+    public synchronized boolean processRunning() {
+    if(process == null) return false;
+    return SafeProcess.processRunning(this.process);
+    }
 
     // Run a very basic process: with no reading from or writing to the Process' iostreams,
     // this just execs the process and waits for it to return
     public int runBasicProcess() {
-    Process prcs = null;
     try {
         // 1. create the process
-        prcs = doRuntimeExec();
+        process = doRuntimeExec();
         // 2. basic waitFor the process to finish
-        this.exitValue = prcs.waitFor();
+        this.exitValue = process.waitFor();
 
         
@@ -184 +236 @@
         exceptionHandler.gotException(ioe);
         } else {
-        logger.error("IOException: " + ioe.getMessage(), ioe);
-        //System.err.println("IOException " + ioe.getMessage());
-        //ioe.printStackTrace();
+        log("IOException: " + ioe.getMessage(), ioe);
         }
     } catch(InterruptedException ie) {
@@ -192 +242 @@
         if(exceptionHandler != null) {
         exceptionHandler.gotException(ie);
-        } else {
-        logger.error("Process InterruptedException: " + ie.getMessage(), ie);
-        //System.err.println("Process InterruptedException " + ie.getMessage());
-        ///ie.printStackTrace(); // an interrupt here is not an error, it can be a cancel action
+        } else { // Unexpected InterruptedException, so printstacktrace
+        log("Process InterruptedException: " + ie.getMessage(), ie);
         }
         
@@ -201 +249 @@
     } finally { 
 
-        if( prcs != null ) {
-        prcs.destroy(); // see runProcess() below
+        if( process != null ) {
+        process.destroy(); // see runProcess() below
         }
     }
@@ -220 +268 @@
                CustomProcessHandler procErrHandler)
     {
-    Process prcs = null;
     SafeProcess.OutputStreamGobbler inputGobbler = null;
     SafeProcess.InputStreamGobbler errorGobbler = null;
@@ -227 +274 @@
     try {
         // 1. get the Process object
-        prcs = doRuntimeExec();
+        process = doRuntimeExec();
         
 
@@ -236 +283 @@
         // send inputStr to process. The following constructor can handle inputStr being null
         inputGobbler = // WriterToProcessInputStream
-            new SafeProcess.OutputStreamGobbler(prcs.getOutputStream(), this.inputStr);
+            new SafeProcess.OutputStreamGobbler(process.getOutputStream(), this.inputStr);
         } else { // user will do custom handling of process' InputStream 
-        inputGobbler = new SafeProcess.OutputStreamGobbler(prcs.getOutputStream(), procInHandler);
+        inputGobbler = new SafeProcess.OutputStreamGobbler(process.getOutputStream(), procInHandler);
         }
 
@@ -244 +291 @@
         if(procErrHandler == null) {
         errorGobbler // ReaderFromProcessOutputStream
-            = new SafeProcess.InputStreamGobbler(prcs.getErrorStream(), splitStdErrorNewLines);
+            = new SafeProcess.InputStreamGobbler(process.getErrorStream(), splitStdErrorNewLines);
         } else {
         errorGobbler
-            = new SafeProcess.InputStreamGobbler(prcs.getErrorStream(), procErrHandler);
+            = new SafeProcess.InputStreamGobbler(process.getErrorStream(), procErrHandler);
         }
 
@@ -253 +300 @@
         if(procOutHandler == null) {
         outputGobbler
-            = new SafeProcess.InputStreamGobbler(prcs.getInputStream(), splitStdOutputNewLines);
+            = new SafeProcess.InputStreamGobbler(process.getInputStream(), splitStdOutputNewLines);
         } else {
         outputGobbler
-            = new SafeProcess.InputStreamGobbler(prcs.getInputStream(), procOutHandler);
+            = new SafeProcess.InputStreamGobbler(process.getInputStream(), procOutHandler);
         }
 
 
             // 3. kick off the stream gobblers
-        this.exitValue = waitForWithStreams(prcs, inputGobbler, outputGobbler, errorGobbler);
+        this.exitValue = waitForWithStreams(inputGobbler, outputGobbler, errorGobbler);
        
     } catch(IOException ioe) {
@@ -267 +314 @@
         exceptionHandler.gotException(ioe);
         } else {
-        logger.error("IOexception: " + ioe.getMessage(), ioe);
-        //System.err.println("IOexception " + ioe.getMessage());
-        //ioe.printStackTrace();
-        }
-    } catch(InterruptedException ie) {
-
+        log("IOexception: " + ioe.getMessage(), ioe);
+        }
+    } catch(InterruptedException ie) { // caused during any of the gobblers.join() calls, this is unexpected so print stack trace
+        
         if(exceptionHandler != null) {
         exceptionHandler.gotException(ie);
+        log("@@@@ Unexpected InterruptedException when waiting for process stream gobblers to die");
         } else {
-        logger.error("Process InterruptedException: " + ie.getMessage(), ie);
-        //System.err.println("Process InterruptedException " + ie.getMessage());
-        ///ie.printStackTrace(); // an interrupt here is not an error, it can be a cancel action
-        }
-
-        // propagate interrupts to worker threads here?
-        // unless the interrupt emanated from any of them in any join()...
-        // Only if the thread SafeProcess runs in was interrupted
-        // do we propagate the interrupt to the worker threads.
-        // http://stackoverflow.com/questions/2126997/who-is-calling-the-java-thread-interrupt-method-if-im-not
-        // "I know that in JCiP it is mentioned that you should never interrupt threads you do not own"
-        // But SafeProcess owns the worker threads, so it have every right to interrupt them
-        // Also read http://stackoverflow.com/questions/13623445/future-cancel-method-is-not-working?noredirect=1&lq=1
-        if(Thread.currentThread().isInterrupted()) {
-        inputGobbler.interrupt();
-        errorGobbler.interrupt();
-        outputGobbler.interrupt();      
-        }
-
-        // On catchingInterruptedException, re-interrupt the thread.
-        // This is just how InterruptedExceptions tend to be handled
-        // See also http://stackoverflow.com/questions/4906799/why-invoke-thread-currentthread-interrupt-when-catch-any-interruptexception
-        // and https://praveer09.github.io/technology/2015/12/06/understanding-thread-interruption-in-java/
-
-        // http://stackoverflow.com/questions/3976344/handling-interruptedexception-in-java
-        // http://stackoverflow.com/questions/4906799/why-invoke-thread-currentthread-interrupt-when-catch-any-interruptexception
-        // "Only code that implements a thread's interruption policy may swallow an interruption request. General-purpose task and library code should never swallow interruption requests."
-        // Does that mean that since this code implements this thread's interruption policy, it's ok
-        // to swallow the interrupt this time and not let it propagate by commenting out the next line?
-        Thread.currentThread().interrupt(); // re-interrupt the thread - which thread? Infinite loop?
+        log("*** Unexpected InterruptException when waiting for process stream gobblers to die:" + ie.getMessage(), ie);
+        }
+
+        // see comments in other runProcess()
+        Thread.currentThread().interrupt();
+    
     } finally { 
-
-        // Moved into here from GS2PerlConstructor which said
-        // "I need to somehow kill the child process. Unfortunately Thread.stop() and Process.destroy() both fail to do this. But now, thankx to the magic of Michaels 'close the stream suggestion', it works fine."
-        // http://steveliles.github.io/invoking_processes_from_java.html
-        // http://www.javaworld.com/article/2071275/core-java/when-runtime-exec---won-t.html?page=2
-        // http://mark.koli.ch/leaky-pipes-remember-to-close-your-streams-when-using-javas-runtimegetruntimeexec        
-        if( prcs != null ) {        
-        prcs.destroy();
-        }
+        //String cmd = (this.command == null) ? Arrays.toString(this.command_args) : this.command;
+        //log("*** In finally of SafeProcess.runProcess(3 params): " + cmd);
+
+        if( process != null ) {
+        log("*** Going to call process.destroy 2");
+        process.destroy();
+        process = null;
+        log("*** Have called process.destroy 2");
+        }
+        
     }
     
@@ -323 +346 @@
     public int runProcess(LineByLineHandler outLineByLineHandler, LineByLineHandler errLineByLineHandler)
     {
-    Process prcs = null;
     SafeProcess.OutputStreamGobbler inputGobbler = null;
     SafeProcess.InputStreamGobbler errorGobbler = null;
@@ -330 +352 @@
     try {
         // 1. get the Process object
-        prcs = doRuntimeExec();
+        process = doRuntimeExec();
         
 
@@ -338 +360 @@
         // send inputStr to process. The following constructor can handle inputStr being null
         inputGobbler = // WriterToProcessInputStream
-        new SafeProcess.OutputStreamGobbler(prcs.getOutputStream(), this.inputStr);
+        new SafeProcess.OutputStreamGobbler(process.getOutputStream(), this.inputStr);
 
         // PROC ERR STREAM to monitor for any error messages or expected output in the process' stderr    
         errorGobbler // ReaderFromProcessOutputStream
-            = new SafeProcess.InputStreamGobbler(prcs.getErrorStream(), splitStdErrorNewLines);     
+            = new SafeProcess.InputStreamGobbler(process.getErrorStream(), splitStdErrorNewLines);      
             // PROC OUT STREAM to monitor for the expected std output line(s)
         outputGobbler
-        = new SafeProcess.InputStreamGobbler(prcs.getInputStream(), splitStdOutputNewLines);
+        = new SafeProcess.InputStreamGobbler(process.getInputStream(), splitStdOutputNewLines);
 
 
@@ -358 +380 @@
 
             // 4. kick off the stream gobblers
-        this.exitValue = waitForWithStreams(prcs, inputGobbler, outputGobbler, errorGobbler);
+        this.exitValue = waitForWithStreams(inputGobbler, outputGobbler, errorGobbler);
        
     } catch(IOException ioe) {
@@ -364 +386 @@
         exceptionHandler.gotException(ioe);
         } else {
-        logger.error("IOexception: " + ioe.getMessage(), ioe);
-        //System.err.println("IOexception " + ioe.getMessage());
-        //ioe.printStackTrace();
-        }
-    } catch(InterruptedException ie) {
-
+        log("IOexception: " + ioe.getMessage(), ioe);       
+        }
+    } catch(InterruptedException ie) { // caused during any of the gobblers.join() calls, this is unexpected so log it
+        
         if(exceptionHandler != null) {
         exceptionHandler.gotException(ie);
+        log("@@@@ Unexpected InterruptedException when waiting for process stream gobblers to die");
         } else {
-        logger.error("Process InterruptedException: " + ie.getMessage(), ie);
-        //System.err.println("Process InterruptedException " + ie.getMessage());
-        ///ie.printStackTrace(); // an interrupt here is not an error, it can be a cancel action
-        }
-
-        // propagate interrupts to worker threads here?
-        // unless the interrupt emanated from any of them in any join()...
-        // Only if the thread SafeProcess runs in was interrupted
-        // do we propagate the interrupt to the worker threads.
-        // http://stackoverflow.com/questions/2126997/who-is-calling-the-java-thread-interrupt-method-if-im-not
-        // "I know that in JCiP it is mentioned that you should never interrupt threads you do not own"
-        // But SafeProcess owns the worker threads, so it have every right to interrupt them
-        // Also read http://stackoverflow.com/questions/13623445/future-cancel-method-is-not-working?noredirect=1&lq=1
-        if(Thread.currentThread().isInterrupted()) {
-        inputGobbler.interrupt();
-        errorGobbler.interrupt();
-        outputGobbler.interrupt();      
-        }
-
-        // On catchingInterruptedException, re-interrupt the thread.
+        log("*** Unexpected InterruptException when waiting for process stream gobblers to die: " + ie.getMessage(), ie);
+        }
+        // We're not causing any interruptions that may occur when trying to stop the worker threads
+        // So resort to default behaviour in this catch?
+        // "On catching InterruptedException, re-interrupt the thread."
         // This is just how InterruptedExceptions tend to be handled
         // See also http://stackoverflow.com/questions/4906799/why-invoke-thread-currentthread-interrupt-when-catch-any-interruptexception
         // and https://praveer09.github.io/technology/2015/12/06/understanding-thread-interruption-in-java/
-
-        // http://stackoverflow.com/questions/3976344/handling-interruptedexception-in-java
-        // http://stackoverflow.com/questions/4906799/why-invoke-thread-currentthread-interrupt-when-catch-any-interruptexception
-        // "Only code that implements a thread's interruption policy may swallow an interruption request. General-purpose task and library code should never swallow interruption requests."
-        // Does that mean that since this code implements this thread's interruption policy, it's ok
-        // to swallow the interrupt this time and not let it propagate by commenting out the next line?
         Thread.currentThread().interrupt(); // re-interrupt the thread - which thread? Infinite loop?
+    
     } finally { 
 
-        // Moved into here from GS2PerlConstructor which said
-        // "I need to somehow kill the child process. Unfortunately Thread.stop() and Process.destroy() both fail to do this. But now, thankx to the magic of Michaels 'close the stream suggestion', it works fine."
+        // Moved into here from GS2PerlConstructor and GShell.runLocal() which said
+        // "I need to somehow kill the child process. Unfortunately Thread.stop() and Process.destroy() both fail to do this. But now, thankx to the magic of Michaels 'close the stream suggestion', it works fine (no it doesn't!)"
         // http://steveliles.github.io/invoking_processes_from_java.html
         // http://www.javaworld.com/article/2071275/core-java/when-runtime-exec---won-t.html?page=2
         // http://mark.koli.ch/leaky-pipes-remember-to-close-your-streams-when-using-javas-runtimegetruntimeexec        
-        if( prcs != null ) {        
-        prcs.destroy();
+        
+        //String cmd = (this.command == null) ? Arrays.toString(this.command_args) : this.command;
+        //log("*** In finally of SafeProcess.runProcess(2 params): " + cmd);
+
+        if( process != null ) {
+        log("*** Going to call process.destroy 1");
+        process.destroy();
+        process = null;
+        log("*** Have called process.destroy 1");
         }
     }
@@ -451 +459 @@
     this.source = src; // STDERR or STDOUT or STDIN
     }
+
+    public String getThreadNamePrefix() {
+    return SafeProcess.streamToString(this.source); 
+    }
     
     public abstract void run(Closeable stream); //InputStream or OutputStream
@@ -465 +477 @@
     }
 
+    public String getThreadNamePrefix() {
+    return SafeProcess.streamToString(this.source); 
+    }
+
     public abstract void gotLine(String line); // first non-null line
     public abstract void gotException(Exception e); // for when an exception occurs instead of getting a line
 }
+
 
 //**************** StreamGobbler Inner class definitions (stream gobblers copied from GLI) **********//
@@ -482 +499 @@
     private LineByLineHandler lineByLineHandler = null;
 
+    protected InputStreamGobbler() {
+    super("InputStreamGobbler");
+    }
+
     public InputStreamGobbler(InputStream is)
     {
+    this(); // sets thread name
     this.is = is;
     this.split_newlines = false;
@@ -490 +512 @@
     public InputStreamGobbler(InputStream is, boolean split_newlines)
     {
+    this(); // sets thread name
     this.is = is;
     this.split_newlines = split_newlines;
@@ -496 +519 @@
     public InputStreamGobbler(InputStream is, CustomProcessHandler customHandler)
     {
+    this(); // thread name
     this.is = is;
     this.customHandler = customHandler;
+    this.adjustThreadName(customHandler.getThreadNamePrefix());
+    }
+
+    
+    private void adjustThreadName(String prefix) {  
+    this.setName(prefix + this.getName());
     }
 
     public void setLineByLineHandler(LineByLineHandler lblHandler) {
     this.lineByLineHandler = lblHandler;
+    this.adjustThreadName(lblHandler.getThreadNamePrefix());
     }
 
@@ -511 +542 @@
         br = new BufferedReader(new InputStreamReader(is, "UTF-8"));
         String line=null;
-        while ( (line = br.readLine()) != null ) {
-
-        if(this.isInterrupted()) { // should we not instead check if SafeProcess thread was interrupted?
-            logger.info("Got interrupted when reading lines from process err/out stream.");
-            //System.err.println("InputStreamGobbler.runDefault() Got interrupted when reading lines from process err/out stream.");
-            break; // will go to finally block
-        }
-
-        //System.out.println("@@@ GOT LINE: " + line);
+        while ( !this.isInterrupted() && (line = br.readLine()) != null ) {
+
+        //log("@@@ GOT LINE: " + line);
         outputstr.append(line);
         if(split_newlines) {
@@ -529 +554 @@
         }
         }
+
     } catch (IOException ioe) {
         if(lineByLineHandler != null) {
         lineByLineHandler.gotException(ioe);
         } else {
-        logger.error("Exception when reading from a process' stdout/stderr stream: ", ioe);
-        //System.err.println("Exception when reading from a process' stdout/stderr stream: ");
-        //ioe.printStackTrace();  
+        log("Exception when reading process stream with " + this.getName() + ": ", ioe);
         }
     } finally {
+        if(this.isInterrupted()) {
+        log("@@@ Successfully interrupted " + this.getName() + ".");
+        }
         SafeProcess.closeResource(br);
     }
@@ -569 +596 @@
     private CustomProcessHandler customHandler = null;
 
+    protected OutputStreamGobbler() {
+    super("stdinOutputStreamGobbler"); // thread name
+    }
+
     public OutputStreamGobbler(OutputStream os) {
+    this(); // set thread name
     this.os = os;
     }
@@ -575 +607 @@
     public OutputStreamGobbler(OutputStream os, String inputstr)
     {
+    this(); // set thread name
     this.os = os;
     this.inputstr = inputstr;
@@ -580 +613 @@
 
     public OutputStreamGobbler(OutputStream os, CustomProcessHandler customHandler) {
+    this(); // set thread name
     this.os = os;
     this.customHandler = customHandler;
@@ -589 +623 @@
     if (inputstr == null) {
         return;
+    }
+
+    // also quit if the process was interrupted before we could send anything to its stdin
+    if(this.isInterrupted()) {
+        log(this.getName() + " thread was interrupted.");
+        return;
     }
     
@@ -612 +652 @@
         */
     } catch (IOException ioe) {
-        logger.error("Exception writing to SafeProcess' inputstream: ", ioe);
-        //System.err.println("Exception writing to SafeProcess' inputstream: ");
-        //ioe.printStackTrace();    
+        log("Exception writing to SafeProcess' inputstream: ", ioe);
     } finally {
         SafeProcess.closeResource(osw);
@@ -632 +670 @@
         runCustom();
     }
-
     }   
 } // end static inner class OutputStreamGobbler
 
+//**************** Static methods **************//
+
+
+    // logger and DebugStream print commands are synchronized, therefore thread safe.
+    public static void log(String msg) {
+    logger.info(msg);
+
+    //System.err.println(msg);
+
+    //DebugStream.println(msg);
+    }
+
+    public static void log(String msg, Exception e) { // Print stack trace on the exception
+    logger.error(msg, e);
+
+    //System.err.println(msg);
+    //e.printStackTrace();
+
+    //DebugStream.println(msg);
+    //DebugStream.printStackTrace(e);
+    }
+
+    public static void log(Exception e) {
+    logger.error(e);
+
+    //e.printStackTrace();
+
+    //DebugStream.printStackTrace(e);
+    }
+
+    public static void log(String msg, Exception e, boolean printStackTrace) {
+    if(printStackTrace) { 
+        log(msg, e);
+    } else {
+        log(msg);
+    }
+    }
+
+    public static String streamToString(int src) {
+    String stream;
+    switch(src) {
+    case STDERR:
+        stream = "stderr"; 
+        break;
+    case STDOUT:
+        stream = "stdout";
+        break;
+    default:
+        stream = "stdin";
+    }
+    return stream;
+    }
 
 //**************** Useful static methods. Copied from GLI's Utility.java ******************
@@ -651 +740 @@
         }
     } catch(Exception e) {
-        logger.error("Exception closing resource: ", e);
-        //System.err.println("Exception closing resource: " + e.getMessage());
-        //e.printStackTrace();
+        log("Exception closing resource: " + e.getMessage(), e);
         resourceHandle = null;
         success = false;
@@ -672 +759 @@
     }
 
+// Moved from GShell.java
+    /** Determine if the given process is still executing. It does this by attempting to throw an exception - not the most efficient way, but the only one as far as I know
+     * @param process the Process to test
+     * @return true if it is still executing, false otherwise
+     */
+    static public boolean processRunning(Process process) {
+    boolean process_running = false;
+
+    try {
+        process.exitValue(); // This will throw an exception if the process hasn't ended yet.
+    }
+    catch(IllegalThreadStateException itse) {
+        process_running = true;
+    }
+    catch(Exception exception) {
+        log(exception); // DebugStream.printStackTrace(exception);
+    }
+    return process_running;
+    }
+
 } // end class SafeProcess