[fpc-pascal] Strange issue with threads

[Jonas Maebe]

On 22 May 2009, at 17:03, Luca Olivetti wrote:

> While I was testing an unrelated issue, I discovered this: under
> windows, with fpc 2.2.4, I try to start 10000 thread (I know it's  
> absurd
> but it's just a test) and have all of them linger around for 10  
> seconds.
> The thread actually started are 121. The problem is that no  
> exception is
> raised, so how can I be sure that a thread is really started in a more
> normal scenario?

You can obtain the "handle" property of the tthread instance and check  
it against whatever "invalid handle" CreateThread returns under  
Windows when it fails (although that will obviously not be portable).

> Is there a hard limit on the number of threads under
> windows?

I'm pretty sure there is one for every OS.

> If so, why no exception when I try to create more?

Because the Windows version of tthread.create does not check for any  
errors. You can submit a bug report about this.

> If I run the same program under Linux, an "EThread: failed to create  
> new
> thread" exception is raised after around 300 threads.

The unix version does check for errors.


Jonas