> From: Igor Stasenko <
[hidden email]>
> Date: April 18, 2010 3:00:02 AM GMT+02:00
> To: Squeak Virtual Machine Development Discussion <
[hidden email]>
> Subject: Re: [Vm-dev] InputSemaphore on Windows
> Reply-To: Squeak Virtual Machine Development Discussion <
[hidden email]>
>
>
> On 16 April 2010 02:07, Andreas Raab <
[hidden email]> wrote:
>>
>> On 4/15/2010 3:18 PM, Henrik Sperre Johansen wrote:
>>>
>>> Is there a reason why this isn't signalled when inputSemaphoreIndex > 0?
>>
>> None. It just doesn't bite me. If it did I would've fixed it already. Got
>> patch?
>>
>>> In sqWin32Window.c, the comment for synchronizedSignalSemaphoreWithIndex
>>> looks somewhat scary...
>>> But looking at the svn logs, it seems it never was used in the
>>> record...Event() functions at all, so I wondered if a problem was
>>> encountered before svn was in use that lead to its removal, or if it's
>>> just not done by default?
>>
>> The short answer is that there are so many potential issues with handling
>> semaphore signals properly that at some point I just gave up. At this point,
>> there is no reliable way to deliver semaphore signals, they can and they
>> *do* get dropped (we've proven that).
>>
> Wait.. lets us separate the issues.
> 1) synchronizedSignalSemaphoreWithIndex() & friends, for signaling an
> arbitrary semaphore
> 2) an input semaphore, which should be signaled if there are any
> events pending for delivery into language side.
>
> For (2) , i remember you promised to fix that in no time (a fix is
> quite trivial) , so then newer images could finally
> stop using polling and use an input semaphore instead.
> Usually, it is not a big problem with dropping an input semaphore
> signals ( if that's ever possible),
> because events tend to come at a regular basis, so even if image-side
> missed a signal, it can catch up later,
> when next event will come by.
>
>> Cheers,
>> - Andreas
>>
>
> --
> Best regards,
> Igor Stasenko AKA sig.
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