Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Allow block_on inside block_in_place inside block_on #2645

Merged
merged 1 commit into from
Jul 15, 2020

Conversation

bdonlan
Copy link
Contributor

@bdonlan bdonlan commented Jul 7, 2020

A fast path in block_on_place was failing to call exit() in the case where we
were in a block_on call.

Fixes: #2639

Motivation

Often synchronous library APIs can be implemented in terms of a private tokio runtime. While it would be preferable to structure calls into these libraries as async calls, this isn't always possible, and so it should be possible to enter a blocking context using block_in_place and then block_on a different runtime. This works on spawned tasks, but fails in block_on calls due to a bug in block_in_place.

Solution

This ensures that exit is called from within block_on contexts, allowing us to enter a different runtime.

A fast path in block_on_place was failing to call exit() in the case where we
were in a block_on call.

Fixes: tokio-rs#2639
@Darksonn Darksonn requested a review from carllerche July 7, 2020 15:55
@Darksonn Darksonn added A-tokio Area: The main tokio crate C-maintenance Category: PRs that clean code up or issues documenting cleanup. M-runtime Module: tokio/runtime labels Jul 7, 2020
Copy link
Member

@carllerche carllerche left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks 👍

@carllerche carllerche merged commit fc63fa2 into tokio-rs:master Jul 15, 2020
hawkw added a commit that referenced this pull request Jul 20, 2020
- docs: misc improvements (#2572, #2658, #2663, #2656, #2647, #2630, #2487, #2621,
  #2624, #2600, #2623, #2622, #2577, #2569, #2589, #2575, #2540, #2564, #2567,
  #2520, #2521, #2572, #2493)
- rt: allow calls to `block_on` inside calls to `block_in_place` that are
  themselves inside `block_on` (#2645)
- net: fix non-portable behavior when dropping `TcpStream` `OwnedWriteHalf` (#2597)
- io: improve stack usage by allocating large buffers on directly on the heap
  (#2634)
- io: fix unsound pin projection in `AsyncReadExt::read_buf` and
  `AsyncWriteExt::write_buf` (#2612)
- io: fix unnecessary zeroing for `AsyncRead` implementors (#2525)
- io: Fix `BufReader` not correctly forwarding `poll_write_buf` (#2654)

- coop: returning `Poll::Pending` no longer decrements the task budget (#2549)

- io: little-endian variants of `AsyncReadExt` and `AsyncWriteExt` methods
  (#1915)
- io: fix panic in `AsyncReadExt::read_line` (#2541)
- task: add [`tracing`] instrumentation to spawned tasks (#2655)
- sync: allow unsized types in `Mutex` and `RwLock` (via `default` constructors)
  (#2615)
- net: add `ToSocketAddrs` implementation for `&[SocketAddr]` (#2604)
- fs: add `OpenOptionsExt` for `OpenOptions` (#2515)
- fs: add `DirBuilder` (#2524)

[`tracing`]: https://crates.io/crates/tracing

Signed-off-by: Eliza Weisman <eliza@buoyant.io>
hawkw added a commit that referenced this pull request Jul 22, 2020
# 0.2.22 (July 2!, 2020)

### Fixes
- docs: misc improvements (#2572, #2658, #2663, #2656, #2647, #2630, #2487, #2621,
  #2624, #2600, #2623, #2622, #2577, #2569, #2589, #2575, #2540, #2564, #2567,
  #2520, #2521, #2493)
- rt: allow calls to `block_on` inside calls to `block_in_place` that are
  themselves inside `block_on` (#2645)
- net: fix non-portable behavior when dropping `TcpStream` `OwnedWriteHalf` (#2597)
- io: improve stack usage by allocating large buffers on directly on the heap
  (#2634)
- io: fix unsound pin projection in `AsyncReadExt::read_buf` and
  `AsyncWriteExt::write_buf` (#2612)
- io: fix unnecessary zeroing for `AsyncRead` implementors (#2525)
- io: Fix `BufReader` not correctly forwarding `poll_write_buf` (#2654)
- io: fix panic in `AsyncReadExt::read_line` (#2541)

### Changes
- coop: returning `Poll::Pending` no longer decrements the task budget (#2549)

### Added
- io: little-endian variants of `AsyncReadExt` and `AsyncWriteExt` methods
  (#1915)
- task: add [`tracing`] instrumentation to spawned tasks (#2655)
- sync: allow unsized types in `Mutex` and `RwLock` (via `default` constructors)
  (#2615)
- net: add `ToSocketAddrs` implementation for `&[SocketAddr]` (#2604)
- fs: add `OpenOptionsExt` for `OpenOptions` (#2515)
- fs: add `DirBuilder` (#2524)

[`tracing`]: https://crates.io/crates/tracing

Signed-off-by: Eliza Weisman <eliza@buoyant.io>
jonhoo added a commit that referenced this pull request Jul 28, 2020
Previously, we would fail to reset the coop budget in this case, making
it so that `coop::poll_proceed` would perpetually yield `Poll::Pending`
in nested executers even when run in `block_in_place`.

This is also a further improvement on #2645.
jonhoo added a commit that referenced this pull request Jul 28, 2020
Previously, we would fail to reset the coop budget in this case, making
it so that `coop::poll_proceed` would perpetually yield `Poll::Pending`
in nested executers even when run in `block_in_place`.

This is also a further improvement on #2645.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
A-tokio Area: The main tokio crate C-maintenance Category: PRs that clean code up or issues documenting cleanup. M-runtime Module: tokio/runtime
Projects
None yet
Development

Successfully merging this pull request may close these issues.

Can't block on a runtime from within a block_in_place call
3 participants