AnyEvent and Strawberry perl issue

[Dirk Koopman]

On 13/03/15 07:33, Marc Lehmann wrote:
> On Wed, Mar 11, 2015 at 05:35:17PM -0400, Laurent <laurent.aml at gmail.com> wrote:
>> Apparently, in my setup of Strawberry Perl 5.20, syswrite reports
>> POSIX::EWOULDBLOCK (140) instead of the WSAEWOULDBLOCK (10035) or EAGAIN.
>> In particular, this makes the readline test fail:
>
> The pain. It never ends.
>
> Anyway, thanks for bringing this to my attention, I had no idea.
>
> This is yet another idiotic bug in perl - the corresponding error code for
> WSAEWOULDBLOCK would be EAGAIN (35), the winsock error codes are generally
> shifted by 10000. This change breaks not only existing perl programs
> (which makes it idiotic), but also most unix programs (which use EAGAIN,
> as EWOULDBLOCK is virtually unused on unix for this).
>

This is nothing new, and not confined to Strawberry Perl. ActiveState 
also had this problem from 5.004 onwards. So I have resorted to this 
sort of nonsense in the past:


     unless ($^O eq 'MSWin32') {
         if ($] >= 5.6) {
             eval {
                 local $^W;
                 require Socket; Socket->import(qw(IPPROTO_TCP 
TCP_NODELAY));
             };
         } else {
             dbg("IPPROTO_TCP and TCP_NODELAY manually defined");
             eval 'sub IPPROTO_TCP {     6 };';
             eval 'sub TCP_NODELAY {     1 };';
         }
     }
     # http://support.microsoft.com/support/kb/articles/Q150/5/37.asp
     # defines EINPROGRESS as 10035.  We provide it here because some
     # Win32 users report POSIX::EINPROGRESS is not vendor-supported.
     if ($^O eq 'MSWin32') {
         eval '*EINPROGRESS = sub { 10036 };' unless defined *EINPROGRESS;
         eval '*EWOULDBLOCK = *EAGAIN = sub { 10035 };' unless defined 
*EWOULDBLOCK;
         eval '*F_GETFL     = sub {     0 };' unless defined *F_GETFL;
         eval '*F_SETFL     = sub {     0 };' unless defined *F_SETFL;
         eval 'sub IPPROTO_TCP  {     6 };';
         eval 'sub TCP_NODELAY  {     1 };';
         $blocking_supported = 0;   # it appears that this DOESN'T work :-(
     }

Git blame tells that this has been in a piece of non-AE code since 2002.

Still works perfectly happily on all known M$ perls.

Dirk
Dirk