TaskManager (GigaSpaces XAP 12.1.0 API)

java.lang.Object
- com.sun.jini.thread.TaskManager

public class TaskManager
extends Object

A task manager manages a single queue of tasks, and some number of worker threads. New tasks are added to the tail of the queue. Each thread loops, taking a task from the queue and running it. Each thread looks for a task by starting at the head of the queue and taking the first task (that is not already being worked on) that is not required to run after any of the tasks that precede it in the queue (including tasks that are currently being worked on).

This class uses the Logger named com.sun.jini.thread.TaskManager to log information at the following logging levels:

**`com.sun.jini.thread.TaskManager`**
Level	Description
`SEVERE`	failure to create a worker thread when no other worker threads exist
`WARNING`	exceptions thrown by `TaskManager.Task` methods, and failure to create a worker thread when other worker threads exist

Author:: Sun Microsystems, Inc.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static interface TaskManager.Task
The interface that tasks must implement

Nested Classes
Modifier and Type	Class and Description
`static interface`	`TaskManager.Task` The interface that tasks must implement

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`firstPending` Index of the first pending task; all earlier tasks are active
`protected float`	`loadFactor` Threshold for creating new threads
`protected static Logger`	`logger` Logger
`protected int`	`maxThreads` Maximum number of threads allowed
`protected List`	`roTasks` Read-only view of tasks
`protected ArrayList<TaskManager.Task>`	`tasks` Active and pending tasks
`protected boolean`	`terminated` True if manager has been terminated
`protected List<com.sun.jini.thread.TaskManager.TaskThread>`	`threads` Active threads
`protected long`	`timeout` Idle time before a thread should exit

Constructor Summary

Constructors
Constructor and Description
`TaskManager()` Create a task manager with maxThreads = 10, timeout = 15 seconds, and loadFactor = 3.0.
`TaskManager(int maxThreads, long timeout, float loadFactor)` Create a task manager.
`TaskManager(int maxThreads, long timeout, float loadFactor, String threadName, int retriesOnIdle)`
`TaskManager(int maxThreads, long timeout, float loadFactor, String threadName, int retriesOnIdle, int threadPriority)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`add(TaskManager.Task t)` Add a new task.
`void`	`addAll(Collection c)` Add all tasks in a collection, in iterator order.
`void`	`addIfNew(TaskManager.Task t)` Add a new task if it is not equal to (using the equals method) to any existing active or pending task.
`int`	`getMaxThreads()` Return the maximum number of threads to use on tasks.
`List<TaskManager.Task>`	`getPending()` Return all pending tasks.
`String`	`getThreadName()`
`int`	`getTotalTasks()` Returns the total number of tasks to be executed and currently executing.
`boolean`	`isTerminated()`
`protected boolean`	`needThread()` Return true if a new thread should be created (ignoring maxThreads).
`boolean`	`remove(TaskManager.Task t)`
`boolean`	`removeIfPending(TaskManager.Task t)` Remove a task if it is pending (not active).
`void`	`setThreadName(String threadName)`
`void`	`terminate()` Interrupt all threads, and stop processing tasks.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - logger
```
protected static final Logger logger
```
    Logger
  - tasks
```
protected final ArrayList<TaskManager.Task> tasks
```
    Active and pending tasks
  - firstPending
```
protected int firstPending
```
    Index of the first pending task; all earlier tasks are active
  - roTasks
```
protected final List roTasks
```
    Read-only view of tasks
  - threads
```
protected final List<com.sun.jini.thread.TaskManager.TaskThread> threads
```
    Active threads
  - maxThreads
```
protected final int maxThreads
```
    Maximum number of threads allowed
  - timeout
```
protected final long timeout
```
    Idle time before a thread should exit
  - loadFactor
```
protected final float loadFactor
```
    Threshold for creating new threads
  - terminated
```
protected boolean terminated
```
    True if manager has been terminated
- Constructor Detail
  - TaskManager
```
public TaskManager()
```
    Create a task manager with maxThreads = 10, timeout = 15 seconds, and loadFactor = 3.0.
  - TaskManager
```
public TaskManager(int maxThreads,
                   long timeout,
                   float loadFactor)
```
    Create a task manager.
    
    Parameters:
    
    maxThreads - maximum number of threads to use on tasks
    
    timeout - idle time before a thread exits
    
    loadFactor - threshold for creating new threads. A new thread is created if the total number of runnable tasks (both active and pending) exceeds the number of threads times the loadFactor, and the maximum number of threads has not been reached.
  - TaskManager
```
public TaskManager(int maxThreads,
                   long timeout,
                   float loadFactor,
                   String threadName,
                   int retriesOnIdle)
```
  - TaskManager
```
public TaskManager(int maxThreads,
                   long timeout,
                   float loadFactor,
                   String threadName,
                   int retriesOnIdle,
                   int threadPriority)
```
- Method Detail
  - addIfNew
```
public void addIfNew(TaskManager.Task t)
```
    Add a new task if it is not equal to (using the equals method) to any existing active or pending task.
  - add
```
public void add(TaskManager.Task t)
```
    Add a new task.
  - setThreadName
```
public void setThreadName(String threadName)
```
  - getThreadName
```
public String getThreadName()
```
  - addAll
```
public void addAll(Collection c)
```
    Add all tasks in a collection, in iterator order.
  - needThread
```
protected boolean needThread()
```
    Return true if a new thread should be created (ignoring maxThreads).
  - removeIfPending
```
public boolean removeIfPending(TaskManager.Task t)
```
    Remove a task if it is pending (not active). Object identity (==) is used, not the equals method. Returns true if the task was removed.
  - remove
```
public boolean remove(TaskManager.Task t)
```
  - terminate
```
public void terminate()
```
    Interrupt all threads, and stop processing tasks. Only getPending should be used afterwards.
  - isTerminated
```
public boolean isTerminated()
```
  - getPending
```
public List<TaskManager.Task> getPending()
```
    Return all pending tasks. A new list is returned each time.
  - getTotalTasks
```
public int getTotalTasks()
```
    Returns the total number of tasks to be executed and currently executing.
  - getMaxThreads
```
public int getMaxThreads()
```
    Return the maximum number of threads to use on tasks.

Class TaskManager

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

logger

tasks

firstPending

roTasks

threads

maxThreads

timeout

loadFactor

terminated

Constructor Detail

TaskManager

TaskManager

TaskManager

TaskManager

Method Detail

addIfNew

add

setThreadName

getThreadName

addAll

needThread

removeIfPending

remove

terminate

isTerminated

getPending

getTotalTasks

getMaxThreads