RFR: 8374862: assert(false) failed: Attempting to acquire lock MDOExtraData_lock/nosafepoint-1 out of order with lock tty_lock/tty -- possible deadlock (running with -XX:+Verbose -XX:+WizardMode -XX:+PrintDeoptimizationDetails) [v6]

[Guanqiang Han]

On Fri, 16 Jan 2026 03:57:52 GMT, Dean Long <dlong at openjdk.org> wrote:

>> No - sorry I forgot that you have to add override to all methods.
>
> My understanding is that we need at least one stringStream, and the code is trying to avoid having two stacked stringStreams, which would mean extra memory footprint and copying.  So I agree the proposed is_buffered() is really a proxy for "do I have a stringStream?" because bufferedStream does not guarantee coherent output by itself.  What if we just live with the inefficiency of having two stringStreams for now?

Thanks, ok, I’ll drop the is_buffered() change. Would it be acceptable to go back to my earlier proposal: pass an explicit “buffering/coherent-output” parameter at the call site so we can use an existing stringStream and avoid double buffering?

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PR Review Comment: https://git.openjdk.org/jdk/pull/29186#discussion_r2697031873