Interprocess Communication

[Marko Aschoff]

Hi ng,

on which level are the synchronization functions QUEUE and NOTIFIER
implemented - OS or LabVIEW? Does LabVIEW for Linux take advantage of
the Linux Kernel IPC / Systen V IPC (semaphores, message queues) - if
so, for which functions?

Queue -> Named Pipe ?
Event Structure -> Message Queue ?
Notifier -> Message Queue ?

Thanks in advance,
Marko

[rolfk]

Marko Aschoff wrote:

> Hi ng,
>
> on which level are the synchronization functions QUEUE and NOTIFIER
> implemented - OS or LabVIEW?

They are LabVIEW specific implementations. They may use some low level
OS features at some point to implement them but you couldn't possibly
treat a LabVIEW Queue or Notifier refnum as an OS handle to the similar
OS resources.

> Does LabVIEW for Linux take advantage of the Linux Kernel
> IPC / Systen V IPC (semaphores, message queues) - if
> so, for which functions?

No, I don't think so at all. They are supposed to work exactly the same
on all LabVIEW platforms and that can be a problem when relying on OS
resources as Windows named pipes can have quite different semantics than
*nix usually have. The same is true for al
l those listed features.

LabVIEW has some powerful internal subsystems such as occurrences and
other things, which those resources are implemented with and that
guarantees much more that those features do actually work the same on
all LabVIEW platforms than if they would rely on some OS features which
can change considerably between platforms and even versions.

Rolf Kalbermatter