What exactly does “Run in a sub-thread” do in regards to TPS files?

[Jay Clements]

There is a check box called “Run in a sub-thread” that pops up in several places throughout cloverleaf in the context of running a tps  – on inbound tps for example.

Image of subthread option

Ive checked all the training manuals, all the docs I have, and clovertech and haven’t had any luck finding out:

 

• What exactly does it do?
• When should we use this?

 

Any feedback would be appreciated! Thanks

RJC

• This topic was modified 3 years, 7 months ago by Jay Clements. Reason: removed word "thread" was in correct usage
• This topic was modified 3 years, 7 months ago by Jay Clements.

Topic

[Jay Clements]

I found this which may be helpful to others:

 

Run in a sub-thread option

• When this option is selected on the Inbound TPS Editor by clicking Edit for TPS Inbound Data, a sub-thread is created under the protocol thread. This sub-thread is used only for data type messages, not those of type reply. There must be a TPS defined; there is no sub-thread if a TPS is not defined.

• There is only one thread involved with any IB/OB thread SMS (that is, TPS).
• All protocol threads have a pre-SMS queue and a post-SMS queue. If there is a TPS defined, messages go in the pre-SMS queue. The pre-SMS queue is skipped if no TPS is defined for the protocol thread. Between the two queues is the TPS that does something with the message and generates more messages.

• If a sub-thread is used, that TPS runs in it. During the time of the TPS processing, the engine is free to do other work. For example, input messages, output messages, move messages as part of the data flow. When the sub-thread has run the TPS procedure, it then signals the engine to pass the results into the post-SMS queue.

• If the defined TPS is small and fast, there is no requirement to use a sub-thread. The overhead of starting the thread would negate any gain. By “fast,” it is meant that it does not parse a message, as that can take time. It also does not access external data.

• In terms of stages, the IB pre and post queues are stages 1 and 2 and the OB queues are stages 10 and 11.

• In general, a single CPU machine gains slightly or even loses by turning on the sub-thread. This is the same as xlates.

• In the same way, a process that is lightly loaded does not gain anything using the sub-thread. There is no work for the engine to do when it runs.

• A sub-thread is helpful when there is a CPU available. It is also helpful when there is other work for the engine to do when the sub-thread is running. Parallel processing of messages is permitted if that is possible in the configuration.

• Note: When using Java TPS UPoCs, the Inbound tab shows the procedure as cljTPS. This is the Tcl interface procedure to Java TPS. When you click Edit, the Java class is shown. Java UPoCs cannot be used if Run in a Sub-thread is enabled

• This reply was modified 3 years, 7 months ago by Jay Clements.

[Jim Kosloskey]

Thanks Jay for sharing that information.

email: jim.kosloskey@jim-kosloskey.com 29+ years Cloverleaf, 59 years IT - old fart.

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