RFR: 8324668: JDWP process management needs more efficient file descriptor handling [v2]

[Gerard Ziemski]

On Fri, 26 Jan 2024 15:57:57 GMT, Jaikiran Pai <jpai at openjdk.org> wrote:

>> Can I please get a review of this change which proposes to address https://bugs.openjdk.org/browse/JDK-8324668?
>> 
>> This change proposes to fix the issue in jdwp where when launching a child process (for the `launch=<cmd>` option), it iterates over an extremely large number of file descriptors to close each one of those. Details about the issue and the proposed fixed are added in a subsequent comment in this PR https://github.com/openjdk/jdk/pull/17588#issuecomment-1912256075. tier1, tier2 and tier3 testing is currently in progress with this change.
>
> Jaikiran Pai has updated the pull request incrementally with one additional commit since the last revision:
> 
>   use the right include for rlim_t - <sys/resource.h>

src/jdk.jdwp.agent/unix/native/libjdwp/exec_md.c line 135:

> 133:         for (; i < max_fd; i++) {
> 134:             (void)close(i);
> 135:         }

I think I'd prefer to see standard:


        rlim_t i;
         for (STDERR_FILENO + 1; i < max_fd; i++) {
             (void)close(i);
         }

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PR Review Comment: https://git.openjdk.org/jdk/pull/17588#discussion_r1467922003