tree cb7321e5fd11ab808b0aa3eae760338eb13abf4a
parent 4b7b09e44f828a2a6b105960835b6439fcfaf829
author Wyatt Hepler <hepler@google.com> 1641491718 -0800
committer CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com> 1641502063 +0000

pw_rpc: Handle replacing a call with an acquired ChannelOutput buffer

- When a pending RPC is called again, move its ChannelOutput buffer to
  the new call object. Previously, the ChannelOutput buffer was left
  active in the original call, which caused crashes.

  Moving the ChannelOutput buffer rather than closing it prevents code
  working with the original call object in another thread from sending a
  stale buffer if the call object is replaced. This is an incomplete
  solution, though, and more thought is needed. If the RPC body uses the
  OutputBuffer before passing it off to the other thread, that thread
  will use a stale buffer reference.
- Rearrange the code that replaces the old call to avoid unlocking and
  relocking, which could cause problems if another call arrived while
  the lock wasn't held.
- Expand tests to cover replacing a call with a ChannelOutput buffer
  acquired.

Bug: 591
Change-Id: Iecb6be66d76a248683319c73fd806896d0a93be1
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/76920
Pigweed-Auto-Submit: Wyatt Hepler <hepler@google.com>
Reviewed-by: Alexei Frolov <frolv@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>