Daemon example - Revision history

JAL: add category

2018-04-20T19:18:13Z

add category

← Older revision		Revision as of 19:18, 20 April 2018
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	~~Sirius~~ '''Daemons''' are a class of objects that run on a thread other than the user that launched them. The thread that launches the <var>Daemon</var> is called the "parent." The <var>Daemon</var> responds to requests from the parent and may optionally pass back to the parent thread the results of commands and <var class="product">[[User Language]]</var> programs.		SOUL '''Daemons''' are a class of objects that run on a thread other than the user that launched them. The thread that launches the <var>Daemon</var> is called the "parent." The <var>Daemon</var> responds to requests from the parent and may optionally pass back to the parent thread the results of commands and <var class="product">[[User Language]]</var> programs.

	See the [[Daemon class\|Daemon class]] and its method pages for detailed information about <var>Daemon</var> behaviors.		See the [[Daemon class\|Daemon class]] and its method pages for detailed information about <var>Daemon</var> behaviors.
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	==See also==		==See also==
	<ul>		<ul>
	<li>[[Daemon class]]		<li>[[Daemon class]] </li>

	<li>[[List of Daemon methods]]		<li>[[List of Daemon methods]] </li>

	<li>[[Stringlist class]]		<li>[[Stringlist class]] </li>

	<li>[[Recordset class]]		<li>[[Recordset class]] </li>
	</ul>		</ul>

			[[Category:SOUL object-oriented programming topics]]

JAL at 23:17, 7 December 2012

2012-12-07T23:17:24Z

← Older revision		Revision as of 23:17, 7 December 2012
Line 1:		Line 1:
	Sirius '''Daemons''' are a class of objects that run on a thread other than the user that launched them. The thread that launches the <var>Daemon</var> is called the "parent". The <var>Daemon</var> responds to requests from the parent and may optionally pass back to the parent thread the results of commands and <var class="product">[[User Language]]</var> programs.		Sirius '''Daemons''' are a class of objects that run on a thread other than the user that launched them. The thread that launches the <var>Daemon</var> is called the "parent." The <var>Daemon</var> responds to requests from the parent and may optionally pass back to the parent thread the results of commands and <var class="product">[[User Language]]</var> programs.

	See the [[Daemon class\|Daemon class]] and its method pages for detailed information about <var>Daemon</var> behaviors.		See the [[Daemon class\|Daemon class]] and its method pages for detailed information about <var>Daemon</var> behaviors.

	==Why use a Daemon?==		==Why use a Daemon?==
	<var>Daemon</var> objects make it easy to capture command output and <var class="product">User Language</var> output to <var>Stringlist</var> objects. They make it easy to keep server sizes low by splitting work between a parent and daemon. The use of Asynchronous daemons allows work to be discharged in "fire and forget" mode, where the <var>Daemon</var> completes a task while the parent thread moves on to other processes.		<var>Daemon</var> objects make it easy to capture command output and <var class="product">User Language</var> output to <var>Stringlist</var> objects. They make it easy to keep server sizes low by splitting work between a parent and daemon. The use of [[Daemon class#Asynchronous and Independent daemons\|Asynchronous and Independent daemons]] allows work to be discharged in "fire and forget" mode, where the <var>Daemon</var> completes a task while the parent thread moves on to other processes.

	==Variable Find conditions==		==Variable Find conditions==

JAL at 23:14, 7 December 2012

2012-12-07T23:14:18Z

← Older revision		Revision as of 23:14, 7 December 2012
Line 1:		Line 1:
	Sirius '''Daemons''' are a class of objects that run on a thread other than the user that launched them. The thread that launches the Daemon is called the "parent". The Daemon responds to requests from the parent and may optionally pass back to the parent thread the results of commands and [[User Language]] programs.		Sirius '''Daemons''' are a class of objects that run on a thread other than the user that launched them. The thread that launches the <var>Daemon</var> is called the "parent". The <var>Daemon</var> responds to requests from the parent and may optionally pass back to the parent thread the results of commands and <var class="product">[[User Language]]</var> programs.

	See the [[Daemon class]] and ~~[[Daemon methods]]~~ pages for detailed information ~~on Daemons and~~ Daemon behaviors.		See the [[Daemon class\|Daemon class]] and its method pages for detailed information about <var>Daemon</var> behaviors.

	=Why use a Daemon?=		==Why use a Daemon?==
			<var>Daemon</var> objects make it easy to capture command output and <var class="product">User Language</var> output to <var>Stringlist</var> objects. They make it easy to keep server sizes low by splitting work between a parent and daemon. The use of Asynchronous daemons allows work to be discharged in "fire and forget" mode, where the <var>Daemon</var> completes a task while the parent thread moves on to other processes.

	~~Daemons make it easy to capture command output and~~ User Language ~~output to Stringlist objects~~. ~~They make it easy~~ to ~~keep server sizes low by splitting work between~~ a ~~parent and daemon~~. ~~The use of Asynchronous daemons allows work to be discharged in~~ "~~fire and forget~~" ~~mode, where the Daemon completes a task while the parent thread moves on~~ to ~~other processes~~.		==Variable Find conditions==
			One problem often encountered in <var class="product">User Language</var> is that <var>Find</var> conditions are bound at compile time. Variable input to a fixed number of conditions, with an unchanging set of field names, is handled well in ordinary <var class="product">User Language</var>. But <var class="product">User Language</var> has no clean mechanism to programmatically set up and execute dynamically generated <var>Find</var>s.

	~~=Variable Find Conditions=~~		Daemons handle this situation very elegantly. In the following program, a <var>Daemon</var> is instantiated, and a small program is built to <var>Find</var> a set of records. The program is submitted to the <var>Daemon</var> in a <var>[[Stringlist class\|Stringlist]]</var>, and the resulting set of found records is returned to the parent thread in a <var>[[Recordset class#SortedRecordSet\|SortedRecordSet]]</var> object.
			<p class="code">Begin
	One problem often encountered in [[Model 204]] [[User Language]] is that FIND conditions are bound at compile time. Variable input to a fixed number of conditions, with an unchanging set of field names, is handled well in ordinary User Language. But User Language has no clean mechanism to programmatically set up and execute dynamically generated FINDs.

	Daemons handle this situation very elegantly. In the following program, a Daemon is instantiated, and a small program is built to ~~FIND~~ a set of records. The program is submitted to the Daemon in a [[Stringlist class\|~~StringList~~]], and the resulting set of found records is returned to the parent thread in a [[Recordset class#SortedRecordSet\|SortedRecordSet]] object.


	Begin

	%FindCriteria is string len 255		%FindCriteria is string len 255
	%Pazuzu is object Daemon		%Pazuzu is object Daemon
	%Sorted is object SortedRecordSet in file CUSTOMER		%Sorted is object SortedRecordSet in file CUSTOMER
	%SubList is object stringList		%SubList is object stringList

	* Any of a variety of FIND conditions can be submitted to the Daemon.		* Any of a variety of FIND conditions can be submitted to the Daemon.
	* In a full application, these conditions could be selected by the user through		* In a full application, these conditions could be selected by the user through
	* a screen or browser interface.		* a screen or browser interface.

	* %FindCriteria = 'RECTYPE = ''C'' '		* %FindCriteria = 'RECTYPE = ''C'' '
	* %FindCriteria = 'NICKNAME IS LIKE ''SI*'' '		* %FindCriteria = 'NICKNAME IS LIKE ''SI*'' '
	%FindCriteria = 'RECTYPE = ''C'' AND LAST_MODIFIED=20101225'		%FindCriteria = 'RECTYPE = ''C'' AND LAST_MODIFIED=20101225'

	%SubList = new		%SubList = new
	Text to %SubList		Text to %SubList
	Begin		Begin
	%BasicSet is object RecordSet in file CUSTOMER		%BasicSet is object RecordSet in file CUSTOMER
	%Sorted is object SortedRecordSet in file CUSTOMER		%Sorted is object SortedRecordSet in file CUSTOMER
	%BasicSet = New		%BasicSet = New
	Find Records to %BasicSet		Find Records to %BasicSet
	{%FindCriteria}		{%FindCriteria}
	End Find		End Find
	Sort records in %BasicSet to %Sorted by NICKNAME		Sort records in %BasicSet to %Sorted by NICKNAME
	%(daemon):returnObject(%Sorted)		%(daemon):returnObject(%Sorted)
	End		End
	End Text		End Text

	%Pazuzu = New		%Pazuzu = New
	%Pazuzu:open('CUSTOMER')		%Pazuzu:open('CUSTOMER')
	%Pazuzu:run(%SubList,,%Sorted)		%Pazuzu:run(%SubList,,%Sorted)

	* Process the returned sorted list		* Process the returned sorted list
	For each record in %Sorted		For each record in %Sorted
	feoname: feo NAME		feoname: feo NAME
	print NICKNAME and NAME(occurrence in feoname) and TCPADDR(occurrence in feoname)		print NICKNAME and NAME(occurrence in feoname) and TCPADDR(occurrence in feoname)
	End For		End For
	End For		End For
			End
	End		</p>

	~~=References=~~

	[[Daemon class]]		==See also==
			<ul>
			<li>[[Daemon class]]

	[[Daemon methods]]		<li>[[List of Daemon methods]]

	[[Stringlist class]]		<li>[[Stringlist class]]

	[[Recordset class]]		<li>[[Recordset class]]
			</ul>

Alan at 15:24, 17 September 2010

2010-09-17T15:24:02Z

← Older revision		Revision as of 15:24, 17 September 2010
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	Sirius '''Daemons''' are a class of objects that run on a thread ~~independent from~~ the user ~~who~~ launched them. The thread that launches the Daemon is called the "~~master~~". The Daemon responds to requests from the ~~master~~ and may optionally pass back to the ~~master~~ thread the results of commands and [[User Language]] programs.		Sirius '''Daemons''' are a class of objects that run on a thread other than the user that launched them. The thread that launches the Daemon is called the "parent". The Daemon responds to requests from the parent and may optionally pass back to the parent thread the results of commands and [[User Language]] programs.

	See the [[Daemon class]] and [[Daemon methods]] pages for detailed information on Daemons and Daemon behaviors.		See the [[Daemon class]] and [[Daemon methods]] pages for detailed information on Daemons and Daemon behaviors.
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	=Why use a Daemon?=		=Why use a Daemon?=

	Daemons make it easy to capture command output and User Language output to Stringlist objects. They make it easy to keep server sizes low by splitting work between a ~~master~~ and daemon. The use of Asynchronous daemons allows work to be discharged in "fire and forget" mode, where the Daemon completes a task while the ~~master~~ thread ~~performs~~ other processes.		Daemons make it easy to capture command output and User Language output to Stringlist objects. They make it easy to keep server sizes low by splitting work between a parent and daemon. The use of Asynchronous daemons allows work to be discharged in "fire and forget" mode, where the Daemon completes a task while the parent thread moves on to other processes.

	=Variable Find Conditions=		=Variable Find Conditions=
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	One problem often encountered in [[Model 204]] [[User Language]] is that FIND conditions are bound at compile time. Variable input to a fixed number of conditions, with an unchanging set of field names, is handled well in ordinary User Language. But User Language has no clean mechanism to programmatically set up and execute dynamically generated FINDs.		One problem often encountered in [[Model 204]] [[User Language]] is that FIND conditions are bound at compile time. Variable input to a fixed number of conditions, with an unchanging set of field names, is handled well in ordinary User Language. But User Language has no clean mechanism to programmatically set up and execute dynamically generated FINDs.

	Daemons handle this situation very elegantly. In the following program, a Daemon is instantiated, and a small program is built to FIND a set of records. The program is submitted to the Daemon in a [[Stringlist class\|StringList]], and the resulting set of found records is returned to the ~~master~~ thread in a [[Recordset class#SortedRecordSet\|SortedRecordSet]] object.		Daemons handle this situation very elegantly. In the following program, a Daemon is instantiated, and a small program is built to FIND a set of records. The program is submitted to the Daemon in a [[Stringlist class\|StringList]], and the resulting set of found records is returned to the parent thread in a [[Recordset class#SortedRecordSet\|SortedRecordSet]] object.

Alan: Created page with "Sirius '''Daemons''' are a class of objects that run on a thread independent from the user who launched them. The thread that launches the Daemon is called the "master". The Da..."

2010-09-17T14:46:53Z

Created page with "Sirius '''Daemons''' are a class of objects that run on a thread independent from the user who launched them. The thread that launches the Daemon is called the "master". The Da..."

New page

Sirius '''Daemons''' are a class of objects that run on a thread independent from the user who launched them. The thread that launches the Daemon is called the "master". The Daemon responds to requests from the master and may optionally pass back to the master thread the results of commands and [[User Language]] programs.

See the [[Daemon class]] and [[Daemon methods]] pages for detailed information on Daemons and Daemon behaviors.

=Why use a Daemon?=

Daemons make it easy to capture command output and User Language output to Stringlist objects. They make it easy to keep server sizes low by splitting work between a master and daemon. The use of Asynchronous daemons allows work to be discharged in "fire and forget" mode, where the Daemon completes a task while the master thread performs other processes.

=Variable Find Conditions=

One problem often encountered in [[Model 204]] [[User Language]] is that FIND conditions are bound at compile time. Variable input to a fixed number of conditions, with an unchanging set of field names, is handled well in ordinary User Language. But User Language has no clean mechanism to programmatically set up and execute dynamically generated FINDs.

Daemons handle this situation very elegantly. In the following program, a Daemon is instantiated, and a small program is built to FIND a set of records. The program is submitted to the Daemon in a [[Stringlist class|StringList]], and the resulting set of found records is returned to the master thread in a [[Recordset class#SortedRecordSet|SortedRecordSet]] object.

Begin

%FindCriteria is string len 255
%Pazuzu is object Daemon
%Sorted is object SortedRecordSet in file CUSTOMER
%SubList is object stringList

* Any of a variety of FIND conditions can be submitted to the Daemon.
* In a full application, these conditions could be selected by the user through
* a screen or browser interface.

* %FindCriteria = 'RECTYPE = ''C'' '
* %FindCriteria = 'NICKNAME IS LIKE ''SI*'' '
%FindCriteria = 'RECTYPE = ''C'' AND LAST_MODIFIED=20101225'

%SubList = new
Text to %SubList
Begin
%BasicSet is object RecordSet in file CUSTOMER
%Sorted is object SortedRecordSet in file CUSTOMER
%BasicSet = New
Find Records to %BasicSet
{%FindCriteria}
End Find
Sort records in %BasicSet to %Sorted by NICKNAME
%(daemon):returnObject(%Sorted)
End
End Text

%Pazuzu = New
%Pazuzu:open('CUSTOMER')
%Pazuzu:run(%SubList,,%Sorted)

* Process the returned sorted list
For each record in %Sorted
feoname: feo NAME
print NICKNAME and NAME(occurrence in feoname) and TCPADDR(occurrence in feoname)
End For
End For

End

=References=

[[Daemon class]]

[[Daemon methods]]

[[Stringlist class]]

[[Recordset class]]