RFR: 8309200: java/net/httpclient/ExecutorShutdown fais intermittently, if connection closed during upgrade [v2]

[Jaikiran Pai]

On Thu, 1 Jun 2023 11:09:37 GMT, Daniel Fuchs <dfuchs at openjdk.org> wrote:

>> The ExecutorShutdown test has been observed failing intermittently, notably if by misfortune the shutdown sequence causes a connection to get aborted while upgrading. The issue is that the `ConnectionAborter` class that allows to mark the connection as being scheduled for closing before a handle to the connection is actually available isn't forwarding the original exception for which closing the connection was requested. When the connection is eventually closed, a generic `IOException: connection closed locally` is raised at the `SocketTube` level, which unfortunately can race with the original cause. 
>> 
>> The fix makes it possible to relay the original cause to the place where the IOException is raised, in order to set it as the cause of the new exception.
>
> Daniel Fuchs has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Review feedback

The changes look fine to me. I have a minor comment about the code in the ConnectionAborter, which I've added inline. It's OK with me if you prefer to maintain it in its current form in the PR.

src/java.net.http/share/classes/jdk/internal/net/http/Exchange.java line 176:

> 174:                 } else {
> 175:                     this.connection = null;
> 176:                     this.cause = null;

Hello Daniel, I had to read this a few times to understand why we are resetting `this.cause`, which we potentially set a few lines above, to `null` here. From what I understand, we only want to set `this.cause` when the `connection` is `null`. Do you think this code could instead of written as:


Throwable cause;
synchronized (this) {
 cause = this.cause;
 if (cause == null) {
     cause = error;
 }
 connection = this.connection;
 if (connection == null) {
     closeRequested = true;
     this.cause = cause;
 } else {
     this.connection = null;
     this.cause = null;
 }
}

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

Marked as reviewed by jpai (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/14251#pullrequestreview-1456894820
PR Review Comment: https://git.openjdk.org/jdk/pull/14251#discussion_r1214079485