NAME

Signal::Unsafe - Unsafe signal handlers made convenient

VERSION

version 0.006

SYNOPSIS

 $Signal::Mask{USR1} = 1;
 $Signal::Unsafe{USR1} = sub {
     my ($signo, $args, $binary) = @_;
     die "Process $args->{int} has run too long";
 }

 for my $pid (@pids) {
	 my $clock = POSIX::RT::Clock->get_cpuclock($pid);
	 push @timers, POSIX::RT::Timer->new(clock => $clock, value => 180, id => $pid);
 }
 $ppoll = IO::PPoll->new();
 $ppoll->mask(\*STDIN, POLLIN);
 # SIGUSR1 may be received during the ppoll, but not outside of it
 $ppoll->poll;

DESCRIPTION

This module provides a single global hash that, much like %SIG, allows one to set signal handlers. Unlike %SIG, it will set "unsafe" ones. You're expected to provide your own safety, for example by masking and then selectively unmasking it as in the synopsis.

VARIABLES

• %Signal::Unsafe

  This hash contains handlers for signals. It accepts various values:

  • If a code-reference is written to it, it will accept use that as handler conjoint with the default $Flags and $Mask.

  • If an array-reference is written to is, it will accept that as a tuple of $handler, $flags and $mask. Handler must be a coderef. $flags must be either an integer value (a bitmask of POSIX::SA_* values, or an array-reference containing some of the following entries:

    • siginfo

    • nodefer

    • restart

    • onstack

    • resethand

    • nocldstop

    • nocldwait

  • If an undefined value is written to it, the handler is reset to default.

• $Signal::Unsafe::Flags

  This contains the default flags. Its initial value is POSIX:SA_SIGINFO

• $Signal::Unsafe::Mask

  This contains the default mask. Its initial value is an empty mask.

SIGNAL HANDLER

The signal handler will be called as soon as the signal is dispatched to the process/thread, without any userland delay. If the SA_SIGINFO flag is set (which is highly recommended), the handler will not receive one but three argument.

• The signal number

  This is simple the number of the signal

• The signal information hash

  This is a hash containing the following entries:

  • signo

  • code

  • errno

  • pid

  • uid

  • status

  • utime

  • stime

  • int

  • ptr

  • overrun

  • timerid

  • addr

  • band

  • fd

  Most values are not meaningful for most signal events.

• The signal information as a binary blob

AUTHOR

Leon Timmermans <leont@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2012 by Leon Timmermans.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.