edu.wisc.ssec.mcidasv.jython

Class Runner

java.lang.Object

java.lang.Thread

edu.wisc.ssec.mcidasv.jython.Runner

All Implemented Interfaces:

Runnable

public final class Runner
extends Thread

This class represents a specialized Thread that creates and executes Commands. A BlockingQueue is used to maintain thread safety and to cause a Runner to wait when the queue is at capacity or has no Commands to execute.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields

Modifier and Type	Field and Description
private Console	console Console that created this Runner instance.
private Interpreter	interpreter The Jython interpreter that will actually run the queued commands.
private boolean	interrupted Not in use yet.
private static org.slf4j.Logger	logger
private BlockingQueue<Command>	queue Queue of Commands awaiting execution.
private static int	QUEUE_CAPACITY The maximum number of Commands that can be queued.
private OutputStreamDemux	STD_ERR Acts like a global error stream that redirects data to whichever Console matches the current thread name.
private OutputStreamDemux	STD_OUT Acts like a global output stream that redirects data to whichever Console matches the current thread name.
private org.python.core.PySystemState	systemState

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor and Description
Runner(Console console) Creates a new "console runner thread" for a given Console.
Runner(Console console, List<String> commands) Creates a new "console runner thread" for a given Console and supplies a List of initial "commands" to be executed.

Method Summary

Modifier and Type	Method and Description
(package private) org.python.core.PyStringMap	copyLocals() Fetches, copies, and returns the interpreter's local namespace.
void	queueBatch(String source, List<String> batch) Queues up a series of Jython statements.
private void	queueCommand(Command command) Queues up a command for execution.
void	queueFile(String name, String path) Queues up a Jython file to be run by interpreter.
void	queueLine(String line) Queues up a line of Jython for execution.
void	queueObject(String name, Object object) Queues the addition of an object to interpreter's local namespace.
void	queueRemoval(String name) Queues the removal of an object from interpreter's local namespace.
void	run() Takes commands out of the queue and executes them.
(package private) void	setCallbackHandler(ConsoleCallback newCallback) Registers a new callback handler.
String	toString()

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, yield

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

logger

private static final org.slf4j.Logger logger

QUEUE_CAPACITY

private static final int QUEUE_CAPACITY

The maximum number of Commands that can be queued.

See Also:

Constant Field Values

STD_OUT

private final OutputStreamDemux STD_OUT

Acts like a global output stream that redirects data to whichever Console matches the current thread name.

STD_ERR

private final OutputStreamDemux STD_ERR

Acts like a global error stream that redirects data to whichever Console matches the current thread name.

queue

private final BlockingQueue<Command> queue

Queue of Commands awaiting execution.

console

private final Console console

Console that created this Runner instance.

systemState

private final org.python.core.PySystemState systemState

interpreter

private final Interpreter interpreter

The Jython interpreter that will actually run the queued commands.

interrupted

private boolean interrupted

Not in use yet.

Constructor Detail

Runner

public Runner(Console console)

Creates a new "console runner thread" for a given Console.

Parameters:

console - Console responsible for adding user input and displaying output. Cannot be null.

Runner

public Runner(Console console,
              List<String> commands)

Creates a new "console runner thread" for a given Console and supplies a List of initial "commands" to be executed.

Parameters:

console - Console responsible for adding user input and displaying output. Cannot be null.

commands - Lines to be run right away. Cannot be null.

Method Detail

setCallbackHandler

void setCallbackHandler(ConsoleCallback newCallback)

Registers a new callback handler. Currently this only forwards the new handler to Interpreter.setCallbackHandler(ConsoleCallback).

Parameters:

newCallback - The callback handler to register.

copyLocals

org.python.core.PyStringMap copyLocals()

Fetches, copies, and returns the interpreter's local namespace.

Returns:

Copy of the interpreter's local namespace.

run

public void run()

Takes commands out of the queue and executes them. We get a lot of mileage out of BlockingQueue; it's thread-safe and will block if the queue is at capacity or empty.

Please note that this method needs to be the first method that gets called after creating a Runner.

Specified by:

run in interface Runnable

Overrides:

run in class Thread

queueBatch

public void queueBatch(String source,
                       List<String> batch)

Queues up a series of Jython statements. Currently each command is treated as though the current user just entered it; the command appears in the input along with whatever output the command generates.

Parameters:

source - Batched command source. Anything but null is acceptable.

batch - The actual commands to execute.

queueLine

public void queueLine(String line)

Queues up a line of Jython for execution.

Parameters:

line - Text of the command.

queueObject

public void queueObject(String name,
                        Object object)

Queues the addition of an object to interpreter's local namespace.

Parameters:

name - Object name as it will appear to interpreter.

object - Object to put in interpreter's local namespace.

queueRemoval

public void queueRemoval(String name)

Queues the removal of an object from interpreter's local namespace.

Parameters:

name - Name of the object to be removed, as it appears to Jython.

See Also:

queueObject(String, Object)

queueFile

public void queueFile(String name,
                      String path)

Queues up a Jython file to be run by interpreter.

Parameters:

name - __name__ attribute to use for loading path.

path - The path to the Jython file.

queueCommand

private void queueCommand(Command command)

Queues up a command for execution.

Parameters:

command - Command to place in the execution queue.

toString

public String toString()

Overrides:

toString in class Thread