Are subvi of reentrant vi need to be specified as rentrant?

[ben64]

It's the first time I need to use reentrant VIs so I'm not familiar with this. I want to test four unit in parallel, so I have 4 clones of the test engine vi (not called dynamically). The test engine vi contains a lot of subVIs, should they also be made reentrant?

Ben64

[P@Anand]

It depends on the need. If you are using USR (Uninitialized Shift Register - More info ) in those sub vi's and want to use the data differently for the different units then make those vi's clone but generally its not required to make the sub vi's clone.

[ben64]

I'm not using any AE in the subs, I will try without making the subVI reentrant.

Thanks.

Ben64

[P@Anand]

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@ben64 wrote:

I'm not using any AE in the subs

Ben64

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But I am Damn sure you will use it in the future.

[ben64]

I've already been using AE a lot for a while, but not in this case.

Ben64

[Ben]

You can use non-rentrant in a re-entrant VI but if both instances are trying to use the same non-reentrant sub-VI, the second will hang waiting fo rthe first to finish using the sub-VI.

If you are talking LVOOP and recursive classes... then it appears everything has to be re-entrant. Well at least I LV insisted I make them all re-entrant.

Ben

[ben64]

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@Ben wrote:

You can use non-rentrant in a re-entrant VI but if both instances are trying to use the same non-reentrant sub-VI, the second will hang waiting fo rthe first to finish using the sub-VI.

If you are talking LVOOP and recursive classes... then it appears everything has to be re-entrant. Well at least I LV insisted I make them all re-entrant.

Ben

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Thanks Ben,

In this case it is not LVOOP and recursive classes. I want to test 4 units in parallel so I have 4 copies of my test engine VIs. From what you're saying it seems I should made some of the subVIs reentrant to avoid the other instances to hang. One of the sub is a test state machine so probably this one also will have subVIS to be made reentrant.

Ben64

[Ben]

Sounds right.

Here are a couple of tip if you run into a situation where you you would love to use an AE in that scenario but can't because the two different re-entrant instances would interfere with each other.

Option 1

Use Call by Ref nodes to invoke the AE and open a new instance of the Ae for each top-level re-entrant VI.

Option 2

Use a DVR to store the data (one for each top-Level) and pass the RDV ref to a pseudo-AE and let act on the DVR data instance instead of data from its internal SR.

Option 3

Use LVOOP methods instead of an AE, and keep the Class data in the Top-level re-entrant.

Ben

[ben64]

Thanks Ben