Tag: race-condition

why there is no race condition using global python variable

I have the following code: What I don’t understand is why I do not have a race condition here? We have global variable, two threads, it suppose to give different values when subtracting and adding, but for me it’s always giving 0. How to make race condition in this example? Is the global variable protected with some synchronisation primitive? Answer

competing regular expressions (race condition)

parsing ply python race-condition regex

I’m trying to use python PLY (lex/yacc) to parse a language called ‘GRBL’. GRBL looks something like this: The ‘G’ Codes tell a machine to ‘go’ (or move) and the coordinates say where. LEX requires us to specify a unique regular expression for every possible ‘token’. So in this case I need a regex that will clearly define ‘G00’ and

Atomic increment of a counter in django

django python race-condition transactions

I’m trying to atomically increment a simple counter in Django. My code looks like this: If I understand Django correctly, this should wrap the function in a transaction and make the increment atomic. But it doesn’t work and there is a race condition in the counter update. How can this code be made thread-safe? Answer Use an F expression: either