I posted a bug report for this a few days ago (2890). I got as far as finding out that it is a file locking problem caused by what looks like a compiler bug re calling the destructor of a struct. The following patch to std.stdio works around the problem, but is hardly a fix.

$ diff dmd/src/phobos/std/stdio.d stdio.d
922c922
<         //return LockingTextWriter(this);
---
>         return LockingTextWriter(this);
925,926c925,926
<         auto result = LockingTextWriter(this);
<         return result;
---
>         //auto result = LockingTextWriter(this);
>         //return result;




On Mon, 27 Apr 2009 22:53:04 +0000, dsimcha wrote:

> The following small test program seems to have a weird deadlock or
> something:
>  It should keep printing the phrase "Doing stuff." forever, but it only
>  gets
> through maybe two iterations before its CPU usage does to zero and it
> stops printing, at least on my computer.  Has anyone noticed any bad
> behavior with std.stdio and multithreading?
> 
> import core.thread, std.stdio;
> 
> void main() {
>     Thread[] myThreads;
>     foreach(i; 0..4) {
>         myThreads ~= new Thread( { doStuff(); }); myThreads[$ -
>         1].start;
>     }
> }
> 
> 
> 
> void doStuff() {
>     while(true) {
>         synchronized {
>             writeln("Doing stuff.");
>         }
>     }
> }
> 
> 
> If the writeln line is commented out, this thing keeps executing the empty loop with measurable CPU usage.

Graham St Jack wrote:
> I posted a bug report for this a few days ago (2890). I got as far as finding out that it is a file locking problem caused by what looks like a compiler bug re calling the destructor of a struct. The following patch to std.stdio works around the problem, but is hardly a fix.
> 
> $ diff dmd/src/phobos/std/stdio.d stdio.d
> 922c922
> <         //return LockingTextWriter(this);
> ---
>>         return LockingTextWriter(this);
> 925,926c925,926
> <         auto result = LockingTextWriter(this);
> <         return result;
> ---
>>         //auto result = LockingTextWriter(this);
>>         //return result;

Thanks! I checked in your fix. As you saw, std.stdio is full of commented-out code that I wrote in desperation. The copy construction bugs are killing me.


Andrei