Re: [boost] [interprocess][process] Synchronizing libraries and efforts (+ bugs)

From: Boris (boriss_at_[hidden])
Date: 2008-08-31 17:07:18

On Sun, 31 Aug 2008 18:23:30 +0200, Ion Gaztañaga <igaztanaga_at_[hidden]>  
wrote:

> [...]-> main thread handle returned by CreateProcess in  
> PROCESS_INFORMATION structure the must be closed and I can't find this  
> in the code.

Changed (I've added a couple of CloseHandle() calls).

> -> child::wait function returns sporadic errors when multiple children  
> are launched and waited. I changed the code from:
>       do
>       {
>            ::GetExitCodeProcess(handle_, &code);
>            ::Sleep(500);
>        } while (code == STILL_ACTIVE);
>        ::WaitForSingleObject(handle_, 0);
>        ::CloseHandle(handle_);
>
> with
>
>        ::WaitForSingleObject(handle_, INFINITE);
>        ::GetExitCodeProcess(handle_, &code);
>        ::CloseHandle(handle_);

Changed.

> ->environment::set does not correctly overwrite existing variables):
>
> void set(const std::string &var, const std::string &value)
> {
>     insert(value_type(var, value);
> }
>
> should be
>
> void set(const std::string &var, const std::string &value)
> {
>     this->operator[](var) = value;
> }

No change required as in Boost.Process 0.3 environment is a typedef of  
std::map<std::string, std::string>.

> -> Using named pipes has been problematic because it returns errors when  
> launching multiple processes aggressively: Error 231 - All Pipes are  
> Busy. This does not happen with anonymous pipes and I think it has some  
> relationship with the guid code. By the way, I think a uuid library is  
> too much to create a unique identifier to be shared with the child a  
> simple atomic count would to the job in my opinion. That would reduce  
> Boost.Process dependencies.

An atomic count might not be sufficient as it would be unique only per  
process. As I used Boost.Uuid only for convenience though I'll replace it  
with an atomic count plus a random number to drop the dependency.

> -> systembuf::close() should call sync() to push the last charaters into  
> the pipe, othewise, characters are lost if the user does not flush the  
> stream.

Changed (in postream::close()).

> -> I've changed the "stream_info::usefile" case in win32_start to  
> support redirecting to files, changing "CREATE_NEW" parameter of  
> CreateFileA with CREATE_ALWAYS.

Changed.

> -> And now, the most important one ;-)
>
> Please, avoid tabs! Read boost development guidelines:

Will change it. :)

Boris