"{ Package: 'stx:libbasic2' }"

"{ NameSpace: Smalltalk }"

AbstractBackgroundJob subclass:#BackgroundJob

	instanceVariableNames:''

	classVariableNames:''

	poolDictionaries:''

	category:'System-Support'

!

!BackgroundJob class methodsFor:'documentation'!

documentation

"

    A BackgroundJob for one-shot computation. When started, it performs it job

    and terminates. User have to explicitly ask job to start again to 

    perform new computation.

    [author:]

        Jan Vrany <jan.vrany@fit.cvut.cz>

    [instance variables:]

    [class variables:]

    [see also:]

        BackgroundJob

"

!

examples

"

    | job text |

    job :=  BackgroundJob named: 'example job' on:[

                Delay waitForSeconds: 3.

                Transcript showCR:'One guy said: ', text

            ].

    text := 'Hello world'.

    job restart.

    Delay waitForSeconds: 5.

    text := 'Ahoj Svete!!'.

    job restart.

    Delay waitForSeconds: 1.

    text := 'Haya, I''m talking fast, you should not see the czech greeting'.

    job restart.

"

! !

!BackgroundJob methodsFor:'processing'!

process

    "Actually perform the job. This method is called from the background worker thread"               

    self process:job

    "Created: / 21-02-2015 / 10:14:04 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

process: aBlock

    aBlock value

    "Created: / 21-02-2015 / 10:19:09 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!BackgroundJob methodsFor:'start & stop'!

restart: aBlock

    "Restart the job, evaluationg aBlock instead of pre-configured job"

    running ifTrue:[

        self stop.

    ].

    self start: aBlock

    "Created: / 21-02-2015 / 10:16:39 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

start: aBlock

    "Start the job, evaluating aBlock instead of pre-configured `job`."

    self start: aBlock withPriority: priority

    "Created: / 21-02-2015 / 10:17:34 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

start: block withPriority: prio

    | t |

    ((t := thread) isNil or:[t isDead]) ifTrue:[

        thread := [

            [

                running := true.

                self process: block.

            ] ensure: [

                running := false.

                thread := nil

            ]

        ] newProcess.

        self setupThread: thread priority: prio.

        thread resume.

    ]

    "Created: / 21-02-2015 / 10:18:47 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!BackgroundJob class methodsFor:'documentation'!

version

    ^ '$Header: /cvs/stx/stx/libbasic2/BackgroundJob.st,v 1.15 2015-02-21 22:42:34 vrany Exp $'

!

version_CVS

    ^ '$Header: /cvs/stx/stx/libbasic2/BackgroundJob.st,v 1.15 2015-02-21 22:42:34 vrany Exp $'

!

version_SVN

    ^ '$Id: BackgroundJob.st,v 1.15 2015-02-21 22:42:34 vrany Exp $'

! !