同时使用读取和写入文件运行Python和C ++

Question

So this one is a doozie, and a little too specific to find an answer online.

I am writing to a file in C++ and reading that file in Python at the same time to move a robot. Or trying to.

When I try running both programs at the same time, the C++ one runs first and then the Python one runs.

Here's the command I use:

./ColorFollow & python fileToHex.py

This happens even if I switch the order of commands. Even if I run them in different terminals (which is the same thing, just covering all bases).

Both the Python and C++ code read / write in 'infinite' loops, so these two should run until I say stop.

The code works fine; when the Python script finally runs the robot moves as intended. It's just that the code doesn't run at the same time.

Is there a way to make this happen, or is this impossible?

If you need more information, lemme know, but the code is pretty much what you'd expect it to be.

Answer 1

If you are using Linux, & will release bash session and in this case, CollorFlow and fileToXex.py will run in different bash sessions.
At the same time, composition ./ColorFollow | python fileToHex.py ./ColorFollow | python fileToHex.py looks interesting, cause you redirect stdout of ColorFollow to fileToHex.py stdin - it can syncronize scripts by printing some code string upon exit, then reading it by fileToHex.py and exit as well.
I would create some empty file like /var/run/ColorFollow.flag and write there 1 when one of processes exit. Not a pipe - cause we do not care which process will start first. So, if next loop step of ColorFollow sees 1 in the file, it deletes it and exits (means that fileToHex already exited). The same - for fileToHex - check flag file each loop step and exit if it exists, after deleting flag file.