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| veeru_hyd |
 Posted: Fri Oct 29, 2010 9:10 am Post subject: Delay 20 Milliseconds |
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Novice
Joined: 28 Oct 2010
Posts: 23
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Hi,
I am working on esql coding to write the code for delaying for 20milliseconds to repost the message in retry mechanism without using timer nodes.
I have written the piece of code below in esql to hold the control in a loop for 20 milli secods, but i am getting a problem. I am providing comment to the result of each statement, what i am getting. Could any one let me know, where or what is the problem?.
DECLARE startTimeStamp TIME;
DECLARE curTimeStamp TIME;
DECLARE outTime TIME;
SET startTimeStamp = CURRENT_TIME; -- Result of this statement: 10:34:22:124
SET outTime = EVAL('startTimeStamp + INTERVAL ''0.02'' SECOND');-- Result of this statement: 10:34:22:144(Incremented with 20 Milli seconds)
SET curTimeStamp = CURRENT_TIME;-- Result of this statement: 10:34:22:124(Getting the same result 'startTimeStamp')
WHILE outTime >= curTimeStamp DO
SET curTimeStamp = CURRENT_TIME;-- Result of this statement: 10:34:22:124(Getting the same result 'startTimeStamp', Its going to infinite loop. Because CURRENT_TIME is not returning the correct value from second time onwards.)
END WHILE;
Thanks,
Veera Kumar |
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| Vitor |
| Posted: Fri Oct 29, 2010 9:22 am Post subject: Re: Delay 20 Milliseconds |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| veeru_hyd wrote: |
| Could any one let me know, where or what is the problem?. |
The problem is you're not reading this, which clearly says:
| Quote: |
| All calls to CURRENT_TIME within the processing of one node are guaranteed to return the same value |
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Insanity is the best defence. |
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| mgk |
| Posted: Fri Oct 29, 2010 9:23 am Post subject: |
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Padawan
Joined: 31 Jul 2003
Posts: 1647
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CURRENT_TIME (and friends) always return the same value through the entire node. This is documented behaviour...
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MGK
The postings I make on this site are my own and don't necessarily represent IBM's positions, strategies or opinions. |
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| veeru_hyd |
| Posted: Fri Oct 29, 2010 9:36 am Post subject: |
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Novice
Joined: 28 Oct 2010
Posts: 23
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Oh!! 
Thank you very much for your valuable reply.
Regards,
Veera |
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| rekarm01 |
| Posted: Fri Oct 29, 2010 9:54 am Post subject: Re: Delay 20 Milliseconds |
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Grand Master
Joined: 25 Jun 2008
Posts: 1415
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| veeru_hyd wrote: |
| Code: |
WHILE outTime >= curTimeStamp DO
SET curTimeStamp = CURRENT_TIME;
END WHILE; |
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One other point: a busy-wait loop is probably the worst way to delay processing within a thread. Other threads might want some CPU time too.
Use the Timer nodes, or perhaps write a wrapper function to call Java's Thread.sleep(). |
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| zpat |
| Posted: Fri Oct 29, 2010 9:56 am Post subject: |
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Jedi Council
Joined: 19 May 2001
Posts: 5867
Location: UK
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| Vitor |
| Posted: Fri Oct 29, 2010 10:46 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| zpat wrote: |
| Do NOT loop like this, you will cause the CPU % to hit 100% and turn a multitasking system into a looping single tasking system. |
Does it have this below v7?
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| mgk |
| Posted: Fri Oct 29, 2010 10:48 am Post subject: |
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Padawan
Joined: 31 Jul 2003
Posts: 1647
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| Quote: |
| Does it have this below v7? |
No, SLEEP is new in 7.0.0.1
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The postings I make on this site are my own and don't necessarily represent IBM's positions, strategies or opinions. |
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