tree 1e17b0c8cd751397038ed41640b94a95eb861003
parent 489c9bbd3d69eb09794f1b8e8a3a894d442ca409
author Roman Elizarov <elizarov@gmail.com> 1567872412 +0300
committer Roman Elizarov <elizarov@gmail.com> 1568110448 +0300

Fixes linearizability of Channel.close in advanced receive+send case

We cannot resume closed receives until all receivers are removed from the list.
Consider channel state: head -> [receive_1] -> [receive_2] -> head
 - T1 called receive_2, and will call send() when it's receive call resumes
 - T2 calls close()

Now if T2's close resumes T1's receive_2 then it's receive gets
"closed for receive" exception, but its subsequent attempt to send
successfully rendezvous with receive_1, producing non-linearizable
execution.