How to make a function thread safe in mc++?

[BartMan]

Greetings,

I was looking at the C#'s "lock()" statement, and I was wondering if there
was an equivalent or recommended way of doing this in MC++.

I have a thread which I am calling a function from mc++, and I was wondering
what
the recommended ways of making it thread safe within the mc++ world.

Thanks in advance for any suggestions.

[BartMan]

RE: How to make a function thread safe in mc++?

Right after I made the post I stumbled accross something that I could use for
thread safety, so I thought I would post in case someone else needs it for a
solution.

Solution:
void Foo()
{
// At the beginning of your function.
System::Threadi ng::Monitor::En ter(this);

.... Do some code work

// Add the end of your function (this has to be called)
System::Threadi ng::Monitor::Ex it(this);
}

"BartMan" wrote:
[color=blue]
> Greetings,
>
> I was looking at the C#'s "lock()" statement, and I was wondering if there
> was an equivalent or recommended way of doing this in MC++.
>
> I have a thread which I am calling a function from mc++, and I was wondering
> what
> the recommended ways of making it thread safe within the mc++ world.
>
> Thanks in advance for any suggestions.[/color]

[Carl Daniel [VC++ MVP]]

Re: How to make a function thread safe in mc++?

BartMan wrote:[color=blue]
> Right after I made the post I stumbled accross something that I could
> use for thread safety, so I thought I would post in case someone else
> needs it for a solution.
>
> Solution:
> void Foo()
> {
> // At the beginning of your function.
> System::Threadi ng::Monitor::En ter(this);
>
> ... Do some code work
>
> // Add the end of your function (this has to be called)
> System::Threadi ng::Monitor::Ex it(this);
> }[/color]

That's precisely what the C# 'lock' construct does.

-cd

[Nemanja Trifunovic]

Re: How to make a function thread safe in mc++?

I think it would be pretty easy to wrap this into a RAII __nogc class
with a little help from gcroot.

[BartMan]

Re: How to make a function thread safe in mc++?

Hello Nemanja,

Thanks for the great idea, I didn't know about gcroot which is really
usefull. :)
Here is my attempt.

public __gc class lock
{
public:
lock(System::Ob ject* obj)
{
threadObject = obj;
System::Threadi ng::Monitor::En ter(threadObjec t);
}
~lock()
{
System::Threadi ng::Monitor::Ex it(threadObject );
}
protected:
gcroot<System:: Object*> threadObject;
};


"Nemanja Trifunovic" wrote:
[color=blue]
> I think it would be pretty easy to wrap this into a RAII __nogc class
> with a little help from gcroot.
>
>[/color]

[Nemanja Trifunovic]

Re: How to make a function thread safe in mc++?

I hope you mean __nogc lock.

__gc classes don't have deterministic destructors. Take a look at an
article I wrote a while ago on the topic:

http://www.codeproject.com/managedcpp/managedraii.asp

[BartMan]

Re: How to make a function thread safe in mc++?

Oops, you are right.
Very good article, thanks for the post!



"Nemanja Trifunovic" wrote:
[color=blue]
> I hope you mean __nogc lock.
>
> __gc classes don't have deterministic destructors. Take a look at an
> article I wrote a while ago on the topic:
>
> http://www.codeproject.com/managedcpp/managedraii.asp
>
>[/color]

[Jochen Kalmbach [MVP]]

Re: How to make a function thread safe in mc++?

Hi Carl!
[color=blue][color=green]
>>Right after I made the post I stumbled accross something that I could
>>use for thread safety, so I thought I would post in case someone else
>>needs it for a solution.
>>
>>Solution:
>>void Foo()
>>{
>>// At the beginning of your function.
>>System::Threa ding::Monitor:: Enter(this);
>>
>>... Do some code work
>>
>>// Add the end of your function (this has to be called)
>>System::Threa ding::Monitor:: Exit(this);
>>}[/color]
>
> That's precisely what the C# 'lock' construct does.[/color]

Almost... the C# also does an try-finally construct..

System::Threadi ng::Monitor::En ter(this);
__try
{
// Do some code work
}
__finally
{
System::Threadi ng::Monitor::Ex it(this);
}

--
Greetings
Jochen

My blog about Win32 and .NET

http://blog.kalmbachnet.de/