[ruby-core:110200] [Ruby master Feature#18982] Add an `exception: false` argument for Queue#push, Queue#pop, SizedQueue#push and SizedQueue#pop

["byroot (Jean Boussier)" <noreply@ruby-lang.org>]

Issue #18982 has been updated by byroot (Jean Boussier).


Works for me. I'll leave this ticket open until I add some more spec and documentation to the existing method.

----------------------------------------
Feature #18982: Add an `exception: false` argument for Queue#push, Queue#pop, SizedQueue#push and SizedQueue#pop
https://bugs.ruby-lang.org/issues/18982#change-99482

* Author: byroot (Jean Boussier)
* Status: Open
* Priority: Normal
----------------------------------------
This replaces [Feature #18965]

Currently these methods raise in three occasions:

  - `ThreadError(queue empty)` for `#pop` in `nonblock=true` mode, and the operation would block.
  - `ThreadError(queue full)` for `SizedQueue#push` in `nonblock=true` mode, and the operation would block.
  - `ClosedQueueError` if trying to `#push` in a closed queue.

I see several reasons to prefer a `nil` return value.

- Queue is often used in conjunction with threads, so you have to be very careful not to rescue an unrelated `ThreadError`.
- Queue if often used for low level code, deep in the stack, so exceptions are costly.

I propose that passing `exception: false` would cause the method to return `nil` instead of raising in the three cases listed above.

The argument `exception: true` is consistent with various other methods such as `IO#read_nonblock(exception: false)`.



-- 
https://bugs.ruby-lang.org/