jmx-dev RFR: 8350939: Revisit Windows PDH buffer size calculation for OperatingSystemMXBean

Leonid Mesnik lmesnik at openjdk.org
Wed Mar 5 19:28:52 UTC 2025


On Mon, 3 Mar 2025 12:22:01 GMT, Kevin Walls <kevinw at openjdk.org> wrote:

> Following on from JDK-8350820, which backed out the _snprintf to snprintf change (JDK-8336289) in OperatingSystemImpl.c on Windows, because the counter names were being truncated (so CPU monitoring was not possible).
> 
> This change moves to snprintf again, but the counter names are not truncated.
> 
> snprintf must need the null terminator to fit inside the buffer length given.  It does not, and snprintf truncates (and always add the null terminator).

I assume you tested the changes, even tests are problemlisted now.

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

Marked as reviewed by lmesnik (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23861#pullrequestreview-2662279073


More information about the jmx-dev mailing list