Pulp

It is likely just the incrementing feature that needs to be thread-safe. The pattern will probably be:

• create a progress object
• create a Queue or similar
• create some threads and give them a reference to the queue, and probably the incrementor that comes with the progress object
• each thread runs in a loop: grab a job from the queue, do it, call queue.task_done(), and increment the progress object
• the main thread calls queue.join() and waits for the work to finish

It's worth considering if there's a way to either wrap or somehow hook into the queue's task_done method, but that's optional. There may not be a reasonable way to do so.

Yes item 1 is likely as simple as the increment() method only being updated. I think most of the work is in the docs.

https://github.com/pulp/pulp/pull/2871#issuecomment-264014822

Based on the conversation on the above PR, it sounds like we only need to add some documentation that states that a single instance of a ProgressBar or ProgressSpinner objects should be used by all threads when processing items in parallel.