forks/pipes and std.socket

[Nick Sabalausky]

"Steven Schveighoffer" <schveiguy at yahoo.com> wrote in message 
news:op.vipr20xfeav7ka at localhost.localdomain...
> On Tue, 07 Sep 2010 16:51:48 -0400, Nick Sabalausky <a at a.a> wrote:
>
>>
>> Ah cool, looking forward to it. I was just about ready to launch into a
>> bunch of std.process improvements myself ;) In the meantime, it seems 
>> that
>> File has an undocumented constructor that takes a file handle instead of 
>> a
>> filename, so that should work for me.
>
> Beware, it takes a file *descriptor*, which is different from a *HANDLE* 
> on windows.  In writing the updated std.process I had to write D code that 
> mimics the internals of DMC's runtime in order to translate between file 
> descriptors and handles, not a pretty sight...
>

I'm just feeding it the values I get from CreatePipe:
http://msdn.microsoft.com/en-us/library/aa365152(VS.85).aspx

Seems to be working fine, though...

> The updates are being held back right now by bug 3979.
>
>> BTW, do any of the upcoming std.process changes do anything to help work
>> around Windows's exec being broken? By that I mean, exec is supposed to
>> *reuse* the current process when launching the new one, but on Windows 
>> (and
>> I *don't* believe this is D-specific) it creates a *new* process and 
>> kills
>> the old one, which fucks up anything that waits on the original process 
>> to
>> finish (such as the command-line). spawn(OVERLAY) has the same problem.
>
> Windows' exec is a hack.  std.process will not use it, instead, we'll use 
> CreateProcess directly.
>

Yea, I've come to the conclusion, too, that exec and spawn(OVERLAY) are 
worthless on Windows. I was going to create and submit a patch that avoids 
them and uses system instead (which *does* maintain the current pid) and 
then exits. But if someone's already been doing this, and using 
CreateProcess directly, then all the better :)

> FWIW, we are not going to support fork or exec individually in 
> std.process.  We will only support creating a new process via fork+exec or 
> CreateProcess.  This is the common functionality among OSes.
>
> If you want fork or exec individually, you have to use them on posix 
> systems only, and call them directly.
>

Sounds good.