RFR: 8267140: Support closing the HttpClient by making it auto-closable [v11]

[Jaikiran Pai]

On Wed, 22 Mar 2023 11:15:38 GMT, Daniel Fuchs <dfuchs at openjdk.org> wrote:

>> Please find here an RFE that makes the `java.net.HttpClient` auto-closeable.
>> 
>> The API has been modeled on `ExecutorService`.
>> 
>> HttpClient::close() is a graceful shutdown and will wait until all operations are terminated before returning.
>> If a request is in progress, and the caller doesn't pull the corresponding data (for instance, the request was sent with a BodyHandler.ofInputStream(), but the caller stopped reading the input stream) then close() may never return.
>> 
>> Therefore, additional methods similar to those present in `ExecutorService` are also proposed. In summary:
>> 
>> - `shutdown()`: initiate a graceful shutdown, but doesn't wait for termination. 
>> - `shutdownNow()`:  initiate an immediate shutdown, attempting to cancel all operations in progress. Doesn't wait for termination.
>> - `awaitTermination(Duration)`: await for termination within the given delay
>> - `isTerminated()` tells whether the client is terminated
>> 
>> New tests have been added to test the proposed behaviors.
>> 
>> HttpClient tests (new and old) are still stable.
>
> Daniel Fuchs has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Minor updates. Added some links
>  - Define operations. Clarify some of the things that may stall an orderly shutdown

test/jdk/java/net/httpclient/AsyncShutdownNow.java line 405:

> 403:                     String msg = "Incorrect uuid header values:[" + uuids + "]";
> 404:                     (new RuntimeException(msg)).printStackTrace();
> 405:                     t.sendResponseHeaders(500, -1);

Given that we are writing out a response body (on the next line), should the second param here be the size of those bytes, instead of `-1`?

test/jdk/java/net/httpclient/HttpClientBuilderTest.java line 42:

> 40: import java.util.List;
> 41: import java.util.Map;
> 42: import java.util.Objects;

The copyright year on this `HttpClientBuilderTest.java` file needs an update.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/13019#discussion_r1145764471
PR Review Comment: https://git.openjdk.org/jdk/pull/13019#discussion_r1145771633