Re: [boost] asio formal review begins

From: Oliver.Kowalke_at_[hidden]
Date: 2005-12-13 02:07:32

>> 	sig::action sa;
>> 	sa.set_handler( SIG_IGN);
>> 	sig::action old_sa( sa.run( SIGPIPE) );
>> 	boost::shared_ptr< void > guard(
>> 		static_cast< void * >( 0),
>> 		boost::bind(
>> 			& sig::action::run,
>> 			old_sa,
>> 			SIGPIPE) );
>
>> 	::write(...)

>As I mentioned in another message, at least on Linux, sendmsg can be
>used as replacement for writev that allows specification of
>MSG_NOSIGNAL.

Yes.

>Your code might potentially be useful on Solaris and
>other platforms that do not support disabling the signal through
>mechanism like MSG_NOSIGNAL, although your code seems to introduce
quite
>a lot of overhead per write call.

The code could be expanded to:

struct sigaction	sa, old_sa;

if ( ::sigemptyset( & sa.sa_mask) < 0)
        throw std::runtime_error( ::strerror( errno) );
                
sa.sa_flags = ZERO; 
sa.sa_handler = SIG_IGN;

if ( ::sigaction( SIGPIPE, & sa, & old_sa) < 0)
        throw std::runtime_error( ::strerror( errno) );

// shared_ptr has to call ::sigaction( SIGPIPE, & old_sa, 0) in order to

// reset original signal handler

So it seams to be only 3 clib-function calls for each write operation.

Oliver