Integrated: 8309305: sun/security/ssl/SSLSocketImpl/BlockedAsyncClose.java fails with jtreg test timeout

[Matthew Donovan]

On Thu, 8 Jun 2023 14:25:26 GMT, Matthew Donovan <mdonovan at openjdk.org> wrote:

> This PR improves the reliability of the BlockedAsyncClose test by addressing an edge case/race condition between the two test threads. The purpose of the test is to verify that an SSLSocket can be closed if a thread is blocked in a write operation. 
> 
> The test starts a "write" thread that writes data to a socket until the output buffer was filled, causing the write operation to block. The main thread then calls `SSLSocket.close()`. The original code used `Thread.sleep(1000)` to wait for the write-thread to block. However, 1 second isn't always long enough and if the write-thread isn't blocked and the output buffer is full (or almost full), the `socket.close()` call may block when it tries to send the close_notify alert. This is the condition that caused this bug.
> 
> My change uses a Lock to determine if the write thread is blocked. In the write thread, the lock creates a critical section around the `write()` call. The main thread uses `tryLock()` with a timeout to determine that the write() call is taking too long and thus likely blocked. 
> 
> While there, I also updated the test to use the SSLContextTemplate class.

This pull request has now been integrated.

Changeset: 8042a50b
Author:    Matthew Donovan <mdonovan at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/8042a50b99a671390910afa5f816894f77255429
Stats:     57 lines in 1 file changed: 20 ins; 24 del; 13 mod

8309305: sun/security/ssl/SSLSocketImpl/BlockedAsyncClose.java fails with jtreg test timeout

Reviewed-by: djelinski

-------------

PR: https://git.openjdk.org/jdk/pull/14378