Switch proxy zip thread-locking to use process-locking instead because "-n=NUM" adds parallel processes (not threads) #872
Description
Switch proxy zip thread-locking to use process-locking instead because -n=NUM adds parallel processes (not threads)
This is for a very specific edge case when running tests using parallel process that require the use of a proxy server that requires authentication. One way to handle proxy server authentication on Chrome is by creating a Chrome Extension zip file at runtime with the necessary proxy credentials. I've already done this by implementing https://stackoverflow.com/a/35293284 in realtime by creating the zip file after a user launches tests with proxy settings (--proxy=USER:PASS@SERVER:PORT). Currently, I'm using thread-locking to make sure that two parallel tests don't try to create the same zip file at the same time. I've recently learned that -n=NUM actually uses multiple parallel processes, which is different from using multiple parallel threads. Therefore, I should update the locking mechanism to use process-locking instead of thread-locking. I haven't encountered any issues with this yet (the probability is small of that overlap window happening), but I better play it safe to make sure that issues with file writing can never happen here.