RFR: JDK-8277795: ldap connection timeout not honoured under contention [v4]

[Daniel Fuchs]

On Fri, 21 Jan 2022 13:06:40 GMT, Rob McKenna <robm at openjdk.org> wrote:

>> This fix attemps to resolve an issue where threads can stack up on each other while waiting to get a connection from the ldap pool to an unreachable server. It does this by having each thread start a countdown prior to holding the pools' lock. (which has been changed to a ReentrantLock) Once the lock has been grabbed, the timeout is adjusted to take the waiting time into account and the process of getting a connection from the pool or creating a new one commences.
>> 
>> Note: this fix also changes the meaning of the connection pools initSize somewhat. In a situation where we have a large initSize and a small timeout the first thread could actually exhaust the timeout before creating all of its initial connections. Instead this fix simply creates a single connection per pool-connection-request. It continues to do so for subsequent requests regardless of whether an existing unused connection is available in the pool until initSize is exhausted. As such it may require a CSR.
>
> Rob McKenna has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains seven commits:
> 
>  - Add method to guard long to int cast
>  - Allow the test to pass on MacOSX
>  - JDK-8277795: whitespace
>  - Add test
>  - JDK-8277795: formatting
>  - JDK-8277795: whitespace cleanup
>  - JDK-8277795: ldap connection timeout not honoured under contention

Marked as reviewed by dfuchs (Reviewer).

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PR: https://git.openjdk.java.net/jdk/pull/6568