Are the Set and Reset method of ManualResetEvent class ato..

Look at this

http://stackoverflow.com/questions/265026/is-setevent-atomic

HTH,
Onkar
http://www.42gears.com

On Aug 14, 10:32 am, "Tony" <z... DeleteThis @263.net> wrote:
> OK, thanks!
> But I still have some doubt whether multi-threads call the Set method of the
> same ManualRestEvent simultaneously.
>
> "Chris Tacke, MVP" <ctacke.at.opennetcf.dot.com>
> wrote:3F2502AF-AD2C-4971-A1B0-C879C12DD...@microsoft.com...
>
> > Atomicity of them shouldn't matter.  When Set is called, an exact, defined
> > behavior will occur for what wait objects get released.  The behavior
> > changes whether Set or Pulse is called and whether it is an auto or manual
> > reset type of event.  IIRC, the CF doesn't support Pulse, but you can look
> > at the API docs for CreateEvent to see ecaxtly what happens for each type
> > in each case.
>
> > --
>
> > Chris Tacke, Embedded MVP
> > OpenNETCF Consulting
> > Giving back to the embedded community
> >http://community.OpenNETCF.com
>
> > "Tony" <z... DeleteThis @263.net> wrote in message
> >news:%23IXQKuIHKHA.4168@TK2MSFTNGP05.phx.gbl...
> >>I have many threads in my C# program, and I used ManualResetEvent for
> >>suspending the working thread which could be waked by other threads.
> >> Since many threads can calling the Set method, I would ask whether the
> >> Set and Reset method of ManualResetEvent are atomic?
>
> >> Thanks!

OK, thanks!
But I still have some doubt whether multi-threads call the Set method of the
same ManualRestEvent simultaneously.

"Chris Tacke, MVP" <ctacke.at.opennetcf.dot.com>
wrote:3F2502AF-AD2C-4971-A1B0-C879C12DD2B6@microsoft.com...
> Atomicity of them shouldn't matter. When Set is called, an exact, defined
> behavior will occur for what wait objects get released. The behavior
> changes whether Set or Pulse is called and whether it is an auto or manual
> reset type of event. IIRC, the CF doesn't support Pulse, but you can look
> at the API docs for CreateEvent to see ecaxtly what happens for each type
> in each case.
>
>
> --
>
> Chris Tacke, Embedded MVP
> OpenNETCF Consulting
> Giving back to the embedded community
> http://community.OpenNETCF.com
>
>
> "Tony" <zmc.DeleteThis@263.net> wrote in message
> news:%23IXQKuIHKHA.4168@TK2MSFTNGP05.phx.gbl...
>>I have many threads in my C# program, and I used ManualResetEvent for
>>suspending the working thread which could be waked by other threads.
>> Since many threads can calling the Set method, I would ask whether the
>> Set and Reset method of ManualResetEvent are atomic?
>>
>> Thanks!
>>
>

There is no such thing as "simultaneous". The processor is executing one
and only one instruction at a time, so if two threads call Set, only one of
them will change its state from non-signalled to signalled. The second one
there becomes a no-op (as it's already signalled). Now *if* you have two
threads waiting on it, and it's an auto-reset event, then both threads will
get released. Which particular caller release which listener would be
non-deterministic, but if that's relevent then you shouldn't be using a
single event anyway.


--

Chris Tacke, Embedded MVP
OpenNETCF Consulting
Giving back to the embedded community
http://community.OpenNETCF.com


"Tony" <zmc.RemoveThis@263.net> wrote in message
news:O9wx1CKHKHA.4024@TK2MSFTNGP02.phx.gbl...
> OK, thanks!
> But I still have some doubt whether multi-threads call the Set method of
> the same ManualRestEvent simultaneously.
>
> "Chris Tacke, MVP" <ctacke.at.opennetcf.dot.com>
> wrote:3F2502AF-AD2C-4971-A1B0-C879C12DD2B6@microsoft.com...
>> Atomicity of them shouldn't matter. When Set is called, an exact,
>> defined behavior will occur for what wait objects get released. The
>> behavior changes whether Set or Pulse is called and whether it is an auto
>> or manual reset type of event. IIRC, the CF doesn't support Pulse, but
>> you can look at the API docs for CreateEvent to see ecaxtly what happens
>> for each type in each case.
>>
>>
>> --
>>
>> Chris Tacke, Embedded MVP
>> OpenNETCF Consulting
>> Giving back to the embedded community
>> http://community.OpenNETCF.com
>>
>>
>> "Tony" <zmc.RemoveThis@263.net> wrote in message
>> news:%23IXQKuIHKHA.4168@TK2MSFTNGP05.phx.gbl...
>>>I have many threads in my C# program, and I used ManualResetEvent for
>>>suspending the working thread which could be waked by other threads.
>>> Since many threads can calling the Set method, I would ask whether the
>>> Set and Reset method of ManualResetEvent are atomic?
>>>
>>> Thanks!
>>>
>>
>
>