The current `NettyRpcEndpointRef.send` can be interrupted because it uses `LinkedBlockingQueue.put`, which may hang the application.
Image the following execution order:
| thread 1: TaskRunner.kill | thread 2: TaskRunner.run
------------- | ------------- | -------------
1 | killed = true |
2 | | if (killed) {
3 | | throw new TaskKilledException
4 | | case _: TaskKilledException _: InterruptedException if task.killed =>
5 | task.kill(interruptThread): interruptThread is true |
6 | | execBackend.statusUpdate(taskId, TaskState.KILLED, ser.serialize(TaskKilled))
7 | | localEndpoint.send(StatusUpdate(taskId, state, serializedData)): in LocalBackend
Then `localEndpoint.send(StatusUpdate(taskId, state, serializedData))` will throw `InterruptedException`. This will prevent the executor from updating the task status and hang the application.
An failure caused by the above issue here: https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/44062/consoleFull
Since `receivers` is an unbounded `LinkedBlockingQueue`, we can just use `LinkedBlockingQueue.offer` to resolve this issue.
Author: zsxwing <zsxwing@gmail.com>
Closes#9198 from zsxwing/dont-interrupt-send.
7bb6d31cff