withMonitor should provide monitor reference

[edsko]

Currently withMonitor is defined as

withMonitor :: ProcessId -> Process a -> Process a
withMonitor pid code = bracket (monitor pid) unmonitor (\_ -> code)

but it should be defined as

withMonitor :: ProcessId -> (MonitorRef -> Process a) -> Process a
withMonitor pid = bracket (monitor pid) unmonitor

Although it is possible, using the existing withMonitor, to wait for a MonitorNotification that matches the appropriate ProcessId, if another monitor exists for the same process ID then this may remove the wrong message from the process's mailbox.

[hyperthunk]

+1 - will need to trawl through the code base and fixup any occurrences that use the old API.

[qnikst]

Addressed by #279

[qnikst]

I've added a new primitive to keep code backward compatible.

[hyperthunk]

@edsko can we close this one off now? There are discussions underway about the naming of withMonitorRef or deprecating the old API (which I agree with), but either way there is now a solution that works.

[mboes]

There are discussions underway about the naming of withMonitorRef or deprecating the old API (which I agree with)

For reference, in #281.

[hyperthunk]

@qnikst there seems to be an open/closed issue loop between this and #281, but I'm pretty sure the code has been merged to master a long time ago. Can we close now?

[qnikst]

We can close this issue now, I don't easily see that #281 was merged, at least it's marked as open on github, but we can check while processing #281.