RFR: 8352568: Test gtest/AsyncLogGtest.java failed at droppingMessage_vm

[David Holmes]

On Tue, 8 Apr 2025 12:41:58 GMT, Johan Sjölen <jsjolen at openjdk.org> wrote:

> Hi,
> 
> The test for dropping messages have started to fail on aarch64 fast debug on Linux only when run as part of a test group. This seems to be a multi-threading issue with the `BufferUpdater`. When the `BufferUpdater` is removed, the issue disappears. This PR changes the code in a few other ways as well:
> 
> 1. Fail if the asynchronous mode isn't "drop" (the test makes no sense with stalling mode)
> 2. Print the entirety of the log file produced if no missing messages are found
> 3. If the thread running the test is unattached, then async UL will emit log messages in synchronous mode. Therefore, if the thread is unattached, the test now fails with an error message.
> 
> If the test fails in the future, then these will give important diagnostic information regarding the state of the test.
> 
> This is a re-worked version of https://github.com/openjdk/jdk/pull/24411

Can you elaborate on what the issue with BufferUpdater was. I admit I'm not clear what it was doing.

test/hotspot/gtest/logging/test_asynclog.cpp line 271:

> 269:     }
> 270: 
> 271:     // The thread is null and deattached.

How does this come about when we control the test execution??

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PR Review: https://git.openjdk.org/jdk/pull/24508#pullrequestreview-2755606003
PR Review Comment: https://git.openjdk.org/jdk/pull/24508#discussion_r2036676598