Global variable mutex when more than one front panel object in VI

[Les__Bartel]

Hi GerdW,

I understand your points and they are well taken. Sometimes I don't need to capture intermediate values, only need the latest value at the current moment. If I need to capture all value changes, I would probably use a queue to read/write.

User tst provided an answer to my question. Based on his/her answer, it would appear that a global variable access IS wrapped with a mutex.

If I need to do a read/modify/write to a global, even an FGV, I would need to implement my own mutex. Though an AE could be written to do this without an explicit mutex (the VI provides its own mutex).

[GerdW]

Hi Les,

tst and me essentially told you the same…

even an FGV, I would need to implement my own mutex.

You didn't understand: with an FGV you get your "mutex" for free as it encapsulates access to "global" data…

[Yamaeda]

Mutex or not, you'd still have race conditions if you have several concurrent writers.

/Y

[crossrulz]

I recommend having a good look at an example I put together: A Look At Race Conditions

[Ben]

Look at my nugget on Action Engines.

I suspect that is the answer you are trying to find.

Ben