RFR: 8253440: serviceability/sa/TestJhsdbJstackLineNumbers.java failed with "Didn't find enough line numbers"

[Kevin Walls]

On Thu, 14 Nov 2024 19:20:55 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

> The test is checking to make sure SA will use what is in the bcp register to determine the current line number rather than just use frame->bcp, which often is not up to date. It spawns a debuggee that sits in a loop that is 10 lines of source. The test executes jstack on the debuggee and determines the current line number from the output. It does this 25 times and expectesto see at least 5 of the 10 line numbers being hit. There's no guarantee it will hit at least five. The chances of this not happening are very very low, but apparently the test has failed a couple of times because only 4 unique lines were hit. I decided to do the simple fix and just lower the threshhold to 4 lines.
> 
> Ran locally on linux-x64. Tier1 in progress.

aha yes that test is a bit of a gamble, we want to see n different numbers, with a range of 10 or less. If the line number is not being reported correctly, it seems unlikely we will see 4 different values, unless they just become random...  8-)

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Marked as reviewed by kevinw (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/22117#pullrequestreview-2438244558