mdns server restarts can chew up UDP endpoints quickly

[bzbarsky-apple]

Problem

On LwIP systems, freeing a UDP endpoint is an async process.

Every time we start the mdns server, it frees all its existing endpoints and starts listening again. We probably do need to do this, in case our set of live interfaces changed....

But this means that we synchronously start using more endpoints, but free the existing ones async. Several calls in a row to StartServer can chew up all our available endpoints.

Proposed Solution

• Option 1: Figure out whether we can stop doing the async release for UDP endpoints.
• Option 2: Figure out whether we can somehow reuse endpoints in the mdns server
• Option 3: Figure out whether we can make fewer StartServer calls
• Option 4: Figure out whether the work of StartServer can happen async. This way if we have two calls in a row to it, the second one would not run until the endpoints freed by the first one are actually free.

Or some combination thereof....

@andy31415 @sagar-apple @msandstedt @tcarmelveilleux

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.