feat: support events is zero for uv_poll

uudiin commented 6 months ago

As the poll() manual says that events field may be specified as zero, in which case the only events that can be returned in revents are POLLHUP, POLLERR, and POLLNVAL. This patch allows luv to support this call method with events equal zero. When the parameters in the lua is an empty string, it means that events is zero.

zhaozg commented 2 weeks ago

LGTM, please @squeek502 give suggestion

squeek502 commented 2 weeks ago

I'm not sure the changes in this PR would have the intended effect judging by the Libuv implementation of uv_poll_start. In both win and unix implementations, events == 0 is an early return:

https://github.com/libuv/libuv/blob/d4ab6fbba4669935a6bc23645372dfe4ac29ab39/src/win/poll.c#L498-L501

https://github.com/libuv/libuv/blob/d4ab6fbba4669935a6bc23645372dfe4ac29ab39/src/unix/poll.c#L137-L138

Other minor things:

Not sure why the CI was failing, will likely want to rebase the PR
This API currently doesn't have any tests in Luv, would be nice to add at least one (not necessarily a blocker for this PR, but would at least allow us to test that these changes work as intended)

zhaozg commented 1 week ago

Please rebase, wait CI pass to merge the PR.

zhaozg commented 6 days ago

I don't think this should be merged until it's proven that passing 0 for events has the intended effect.

sure

luvit / luv

feat: support events is zero for uv_poll #702