tree 3d1a8358d9f82581f7f3c5cdaaf89c4d95bace18
parent c3cec48b4f63c1bb7fdb7250bfcab51c106156ed
author Bor Kae Hwang <borkaehw@lucidchart.com> 1571056664 -0700
committer Copybara-Service <copybara-worker@google.com> 1571056714 -0700

Send and receive work requests via proxy and multiplexer

This is the attempt to solve issue #2832.
The design doc has been approved [Multiplex persistent worker](https://docs.google.com/document/d/1OC0cVj1Y1QYo6n-wlK6mIwwG7xS2BJX7fuvf1r5LtnU/edit?usp=sharing).

Two minor design changes from design doc
- Number of WorkerProxy is still limited by `--worker_max_instances`.
- We merge worker multiplexer sender and receiver to one WorkerMultiplxer, WorkerProxy sends request to worker process directly.

Closes #6857.

PiperOrigin-RevId: 274560006