Promptly freeing the per-thread cached direct buffers when a thread exits

Tony Printezis tprintezis at
Fri Apr 6 17:11:39 UTC 2018

Tony Printezis | @TonyPrintezis | tprintezis at

On April 6, 2018 at 12:16:10 PM, David Lloyd (david.lloyd at wrote:

On Fri, Apr 6, 2018 at 8:57 AM, Tony Printezis <tprintezis at>
>> ThreadLocal clearing
> Could you clarify what you mean by ThreadLocal clearing?

I mean calling ThreadLocal#remove().

I see. So, anyone who subclasses ThreadLocal can override remove(). And if
remove() is called by Thread::exit, it can be used as an exit hook. (David
Holmes, if this is what you meant in your e-mail: apologies; I

> I like the suggestion to add an overridable exit() method to ThreadLocal.
> you want to avoid calling user code by Thread::exit, would adding
> ThreadLocals (which are tagged appropriately) to a queue for later
> processing a better approach (similar to the mechanism used for
References /
> ReferencesQueues)? The user can of course create a memory leak by not
> polling the queue frequently enough. But, that’s also the case for
> References. And at least user code cannot block Thread::exit.

It's more complexity, and at some point you have to ask: is it better
to block thread A or thread B? At least blocking thread A is somewhat

I agree re: it’d add complexity. #simplify :-)



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