Re: gspawn(-win32): why helper?

[muppet <scott asofyet org>]

On Nov 24, 2006, at 2:29 PM, Felix Kater wrote:

> when glib spawns processes it starts a helper process first which
> itself then starts the wanted process.
>
> I've studied the gspawn(-win32).c and the win32 helper code, too,
> however, I simply don't understand the need of the helper process. :-/

This comment, at the top of gspawn-win32.c, says that it's basically  
because win32 sucks.  Er, i mean, because win32 doesn't have a proper  
fork().

/*
* Implementation details on Win32.
*
* - There is no way to set the no-inherit flag for
*   a "file descriptor" in the MS C runtime. The flag is there,
*   and the dospawn() function uses it, but unfortunately
*   this flag can only be set when opening the file.
* - As there is no fork(), we cannot reliably change directory
*   before starting the child process. (There might be several threads
*   running, and the current directory is common for all threads.)
*
* Thus, we must in most cases use a helper program to handle closing
* of (inherited) file descriptors and changing of directory. The
* helper process is also needed if the standard input, standard
* output, or standard error of the process to be run are supposed to
* be redirected somewhere.
*
* The structure of the source code in this file is a mess, I know.
*/


The simple tests you mentioned don't involve changing directories or  
inheriting file descriptors.