How Does LabVIEW Handle Multiprocessing and Multithreading?

Question

INTRO

multiprocessing = using multiple CPU cores to complete a task (each core has separate memory, thus requires pipes and data structures for each core to "talk" to each other")

multithreading = using multiple threads (that are on a single CPU core) with a task scheduler to complete a task (all threads share same memory on CPU core)

static (temporal) multithreading - take advantage of idle I/O time by scheduling tasks to occur sequentially without pause during cache misses (i.e. waiting to read/write to an I/O device); used for I/O-bound tasks
dynamic (simultaneous) multithreading - take advantage of instructions that can happen at the same time (on Intel chips, this is called "Hyperthreading"); used for CPU-bound tasks
- e.g.

a = b*c //Task 1
d = e*f //Task 2
g = a*d //Task 3

// Task 1 and 2 don't depend on each other, and hence can be run in parallel

QUESTION

Given the above, how can I control in LabVIEW which cores I use to multiprocess a task (not multithread)?

srm srm · Accepted Answer · 2019-11-18T21:07:13

LabVIEW inherently parses the dataflow out to multiple processors and multiple threads to as much parallelism as the system is analyzed to stand. THERE ARE ALMOST ZERO CASES WHERE YOU SHOULD SPECIFY THE THREADING MODEL OF THE CODE. The Timed Loop and Timed Structure capabilities should be considered strictly for real-time systems, not for execution on the desktop systems (Windows, Mac, or Linux). If you attempt to specify the threading model, you will almost certainly get less performance than the sophisticated model already computed by the compiler and run-time engine.

How Does LabVIEW Handle Multiprocessing and Multithreading?

2 Answers