Bump tokio from 0.1.22 to 0.2.19

[dependabot-preview]

Bumps tokio from 0.1.22 to 0.2.19.

Release notes

Sourced from tokio's releases.

Tokio v0.2.19

Fixes

• docs: misc improvements (#2400, #2405, #2414, #2420, #2423, #2426, #2427, #2434, #2436, #2440).
• rt: support block_in_place in more contexts (#2409, #2410).
• stream: no panic in merge() and chain() when using size_hint() (#2430).
• task: include visibility modifier when defining a task-local (#2416).

Added

• rt: runtime::Handle::block_on (#2437).
• sync: owned Semaphore permit (#2421).
• tcp: owned split (#2270).

Tokio v0.2.18

Fixes a regression with LocalSet that allowed !Send futures to cross threads.

This change makes LocalSet !Send. The Send implementation was accidentally added in v0.2.14. Removing the Send implementation is not considered a breaking change as it fixes a soundness bug and the implementation was accidental.

Fixes

• task: LocalSet was incorrectly marked as Send (#2398)
• io: correctly report WriteZero failure in write_int (#2334)

Tokio 0.2.17

This release fixes a bug in the threaded scheduler that could result in panics under load (see #2382). Additionally, the default number of worker threads now uses the logical CPU count, so it will now respect scheduler affinity and cgroups CPU quotas.

Fixes

• rt: bug in work-stealing queue (#2387)

Changes

• rt: threadpool uses logical CPU count instead of physical by default (#2391)

Tokio 0.2.16

This release fixes a regression in tokio::sync and a bug in tokio::fs::copy. It also adds a new APIs to tokio::time and tokio::io.

Fixes

• sync: fix a regression where Mutex, Semaphore, and RwLock futures no longer implement Sync (#2375)
• fs: fix fs::copy not copying file permissions (#2354)

Added

• time: added deadline method to delay_queue::Expired (#2300)
• io: added StreamReader (#2052)

Tokio v0.2.15

Fixes a queue regression and adds a new disarm fn to mpsc::Sender.

Fixes

... (truncated)

Commits

• ce9eabf chore: prepare v0.2.19 release (#2441)
• 894eb8b runtime: improve runtime and handle doc (#2440)
• 3572ba5 task: update doc on spawn_blocking and block_in_place (#2436)
• d8139fe Add Handle::block_on method (#2437)
• 9bcb506 docs: make it easier to discover extension traits (#2434)
• a3aab86 io: track rustfmt/clippy changes (#2431)
• 236629d stream: fix panic in Merge and Chain size_hint (#2430)
• f83f638 task: link to lib.rs in spawn_blocking documentation (#2426)
• 1397406 io: fix typo on AsyncWrite doc (#2427)
• 6349efd sync: improve mutex documentation (#2405)
• Additional commits viewable in compare view

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[dependabot-preview]

Superseded by #45.