Bug 34028 - NetworkStream.Close() had better be usable under multithreading async scenario
Summary: NetworkStream.Close() had better be usable under multithreading async scenario
Status: NEW
Alias: None
Product: Class Libraries
Classification: Mono
Component: System (show other bugs)
Version: unspecified
Hardware: PC Linux
: --- enhancement
Target Milestone: Untriaged
Assignee: Bugzilla
URL:
Depends on:
Blocks:
 
Reported: 2015-09-17 01:43 UTC by Atsushi Eno
Modified: 2015-09-17 07:50 UTC (History)
2 users (show)

Tags:
Is this bug a regression?: ---
Last known good build:

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Status:
NEW

Description Atsushi Eno 2015-09-17 01:43:58 UTC
This guy (@melponn at twitter) reported on his some session talk that NetworkStream.Close() causes native crash, when it is used under multithreading circumstance.
http://www.slideshare.net/melpon/mono-is-dead/64

(The slides title is in quite nasty words, but skip that, we Japanese don't know English well in general...)

Here is excerpt of repro code, should be called about 100000 times to reproduce the crash.

static async Task TestConnect() {
  try {
    var client = new TcpClient();
    var task = Task.Run( () => client.ConnectAsync("localhost", 8080));
    client.Close();
    await task.ConfigureAwait(false);
  } catch (Exception) { 
  } 
}

So far the native crash output is not provided as useful text, only image, at:
http://www.slideshare.net/melpon/mono-is-dead/63

Since NetworkStream.Close() is not supported in multithreading use, it should rather be called by design, but there are some general? expectation on such usage [*1], so maybe we'd rather want this to have thread-safe.

[*1] http://stackoverflow.com/questions/12421989/networkstream-readasync-with-a-cancellation-token-never-cancels
Comment 1 INOMATA Kentaro 2015-09-17 07:50:03 UTC
the whole repro code and native stack traces are provided at:
http://melpon.org/wandbox/permlink/mP7uNt7u8xwXsImw