AM Handler and permissible functions

[vchuravy]

Is there a set of functions that is permissible to be called from within an active message handler?

ucx/src/ucp/api/ucp_def.h

Lines 620 to 623 in 2c81364

	* The callback is always called from the progress context, therefore calling
	* @ref ucp_worker_progress() is not allowed. It is recommended to define
	* callbacks with relatively short execution time to avoid blocking of
	* communication progress.

explicitly disallows ucp_worker_progress, but are there any other?

What about concurrent accesses when the worker is initialized with UCX_THREAD_MODE_MULTI? Is it safe to call ucp_worker_progress from another thread?

I am asking since I just encountered a scenario where I called ucp_worker_progress from within the am handler because I was using concurrent tasks in Julia and I switched from the handler to the progress task...

[yosefe]

• Only ucp_worker_progress and functions which may destroy the relevant objects (ep/worker/context) are not allowed
• When the worker is initialized with UCX_THREAD_MODE_MULTI it's safe to call ucp_worker_progress from multiple threads

[vchuravy]

Thanks that helps a lot.