Re: notifying from inside or outside

On 5/12/2025 1:52 PM, Kaz Kylheku wrote:

On 2025-05-09, Bonita Montero <Bonita.Montero@gmail.com> wrote:

So for Windows it's the best to notify individually while holding the
mutex.
All tests are with 31 threads waiting for a notification and one thread
which is notifying.

 When you hit a condition variable while holding the mutex, you're
including, in the mutex's critical region, all those instructions needed
to perform that operation, possibly requiring a trip to the kernel.
 There have to be conditions (no pun intended) under which that causes
a problem; you're just not hitting them in your test case.
 

Signalling from outside vs inside is a pretty old debate. I say signal from outside. Wait morphing aside for a moment...
He made a "correction" over in comp.lang.c++:
_______________
The Windows-times were summed-up times where each iteration included
the former iterations. Now it's corrected:
10000 rounds
inside:
         one:
                 2.04687 seconds
         all:
                 4 seconds
outside:
         one:
                 1.03125 seconds
         all:
                 1.14062 seconds
Am 09.05.2025 um 15:06 schrieb Bonita Montero:
[...]
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