Author: stas Date: Wed Nov 24 08:52:16 2004 New Revision: 106429 URL: http://svn.apache.org/viewcvs?view=rev&rev=106429 Log: Problems with Catching Signals under Perl 5.8.x+
Modified: perl/modperl/docs/trunk/src/docs/2.0/user/troubleshooting/troubleshooting.pod Modified: perl/modperl/docs/trunk/src/docs/2.0/user/troubleshooting/troubleshooting.pod Url: http://svn.apache.org/viewcvs/perl/modperl/docs/trunk/src/docs/2.0/user/troubleshooting/troubleshooting.pod?view=diff&rev=106429&p1=perl/modperl/docs/trunk/src/docs/2.0/user/troubleshooting/troubleshooting.pod&r1=106428&p2=perl/modperl/docs/trunk/src/docs/2.0/user/troubleshooting/troubleshooting.pod&r2=106429 ============================================================================== --- perl/modperl/docs/trunk/src/docs/2.0/user/troubleshooting/troubleshooting.pod (original) +++ perl/modperl/docs/trunk/src/docs/2.0/user/troubleshooting/troubleshooting.pod Wed Nov 24 08:52:16 2004 @@ -363,6 +363,68 @@ + +=head2 Problems with Catching Signals under Perl 5.8.x+ + +Starting from 5.8.0 Perl delays signal delivery, making signals +safe. This change may break previously working code. For more +information please see: +http://search.cpan.org/dist/perl/pod/perl58delta.pod#Safe_Signals and +http://search.cpan.org/dist/perl/pod/perlipc.pod#Deferred_Signals_%28Safe_Signals%29 + +For example if you had the alarm code: + + eval { + local $SIG{ALRM} = sub { die "alarm" }; + alarm 3; + sleep 10; # in reality some real code should be here + alarm 0; + }; + die "the operation was aborted" if $@ and $@ =~ /alarm/; + +It may not work anymore. Starting from 5.8.1 it's possible to +circumvent the safeness of signals, by setting: + + $ENV{PERL_SIGNALS} = "unsafe"; + +as soon as you start your program (e.g. in the case of mod_perl in +startup.pl). + +For more information please refer to: +http://search.cpan.org/dist/perl/pod/perl581delta.pod#Unsafe_signals_again_available +and http://search.cpan.org/dist/perl/pod/perlrun.pod#PERL_SIGNALS + +But most likely this is not what you want (since that circumvention +makes your code unsafe). The proper solution that works correctly +across all 5.8.x+ versions is to use the POSIX signal handling, which +bypasses perl signal mechanism. Our example should be rewritten as +follows: + + use POSIX qw(SIGALRM); + eval { + POSIX::sigaction(SIGALRM, + POSIX::SigAction->new(sub { die "alarm" })) + or die "Error setting SIGALRM handler: $!\n"; + alarm 3; + sleep 10; # in reality some real code should be here + alarm 0; + }; + die "the operation was aborted" if $@ and $@ =~ /alarm/; + +For more details see: +http://search.cpan.org/dist/perl/ext/POSIX/POSIX.pod#POSIX::SigAction + + + + + + + + + + + + =head2 APR::Socket::recv: (11) Resource temporarily unavailable at ... You need to make sure that the socket is set to L<blocking IO --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
