blocking = hang

[quininer]

Version

├── tokio v0.1.15
│   ├── tokio-codec v0.1.1
│   │   └── tokio-io v0.1.11
│   ├── tokio-current-thread v0.1.4
│   │   └── tokio-executor v0.1.6
│   ├── tokio-executor v0.1.6 (*)
│   ├── tokio-fs v0.1.5
│   │   ├── tokio-io v0.1.11 (*)
│   │   └── tokio-threadpool v0.1.11
│   │       └── tokio-executor v0.1.6 (*)
│   │   └── tokio-io v0.1.11 (*)
│   ├── tokio-io v0.1.11 (*)
│   ├── tokio-reactor v0.1.8
│   │   ├── tokio-executor v0.1.6 (*)
│   │   └── tokio-io v0.1.11 (*)
│   ├── tokio-sync v0.1.2
│   ├── tokio-tcp v0.1.3
│   │   ├── tokio-io v0.1.11 (*)
│   │   └── tokio-reactor v0.1.8 (*)
│   ├── tokio-threadpool v0.1.11 (*)
│   ├── tokio-timer v0.2.10
│   │   └── tokio-executor v0.1.6 (*)
│   ├── tokio-udp v0.1.3
│   │   ├── tokio-codec v0.1.1 (*)
│   │   ├── tokio-io v0.1.11 (*)
│   │   └── tokio-reactor v0.1.8 (*)
│   └── tokio-uds v0.2.5
│       ├── tokio-codec v0.1.1 (*)
│       ├── tokio-io v0.1.11 (*)
│       └── tokio-reactor v0.1.8 (*)
└── tokio-threadpool v0.1.11 (*)

Platform

Linux btw 4.20.8-arch1-1-ARCH #1 SMP PREEMPT Wed Feb 13 00:06:58 UTC 2019 x86_64 GNU/Linux

Subcrates

tokio-threadpool

Description

Unable to release blocking thread when a timeout occurs.

Sometimes blocking will go into a bad state. Even if there is no blocking task is running, it is still always NoCapacity.

https://gist.github.com/quininer/691caf86ec734dadc9d8590893825284

Note that this happens in hyper TokioThreadpoolGaiResolver @seanmonstar , which causes dns response to never return.

[quininer]

Related #726 .

[carllerche]

This is kind of expected... a blocking call (right now at least) cannot be interrupted. You set the max number of blocking threads to 10, so you can get 10 concurrent sleeps. Could you clarify what you would expect would happen in this case?

[quininer]

You are right... I misunderstood what happened, the blocking behind was never executed because it was canceled by timeout and not because of NoCapacity.

I think I encountered the same problem with #726 on tokio-threadpool 0.1.11.