X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDevel%2FGlobalDestruction.pm;h=949d1d4e83d841bc30e3ed9685b2d329ecb03b86;hb=5629eb97bd5b25e57bec2dc3920728b7a89a4e29;hp=3bb0b7c048ebb5c9c4291d9be12a684650682a32;hpb=df69e815211456320c2b4599135f4e3681c8f63b;p=p5sagit%2FDevel-GlobalDestruction.git diff --git a/lib/Devel/GlobalDestruction.pm b/lib/Devel/GlobalDestruction.pm index 3bb0b7c..949d1d4 100644 --- a/lib/Devel/GlobalDestruction.pm +++ b/lib/Devel/GlobalDestruction.pm @@ -3,7 +3,7 @@ package Devel::GlobalDestruction; use strict; use warnings; -our $VERSION = '0.08'; +our $VERSION = '0.09'; use Sub::Exporter::Progressive -setup => { exports => [ qw(in_global_destruction) ], @@ -25,92 +25,18 @@ elsif (eval { }) { # the eval already installed everything, nothing to do } -# Not core nor XS -# The whole thing is in an eval to prevent perl from parsing it in the -# first place under perls where none of this is needed -# else { - eval <<'PP_IGD' or die $@; - -# SpeedyCGI runs END blocks every cycle but somehow keeps object instances -# hence DIAF -die("The pure-perl version of @{[__PACKAGE__]} can not function correctly under CGI::SpeedyCGI. " - . "Please ensure you have a working compiler, and reinstall @{[__PACKAGE__]} to enable the XS " - . "codepath.\n" -) if $CGI::SpeedyCGI::i_am_speedy; - -my ($in_global_destruction, $before_is_installed); - -sub in_global_destruction () { $in_global_destruction } - -# end_av trick suggested by liz++ -require B; -my $add_endblock = sub { - push @{ B::end_av()->object_2svref }, sub { $in_global_destruction = 1 }; -}; - -# This block will fire towards the end of the program execution -# Use it to inject an END block which is guaranteed to run last -# (as long as something else doesn't inject yet another block in -# the same manner afterwards, at which point it hardly matters -# anyway) -# -END { $add_endblock->() } - -# threads do not execute the global ENDs (it would be stupid). However -# one can register a new thread-local END from within a thread, and -# achieve the same result. A logical place to do this would be CLONE, which -# is claimed to run in the context of the new thread. However this does -# not really seem to be the case - any END inserted in a CLONE is ignored :( -# Hence blatantly hooking threads::create -# -if ($INC{'threads.pm'}) { - require Scalar::Util; - - my $orig_create = threads->can('create'); - no warnings 'redefine'; - - *threads::create = sub { - my $class = shift; - my $target = shift; - - unless ( (Scalar::Util::reftype($target)||'') eq 'CODE' ) { - no strict 'refs'; - $target = \&{ caller() . "::$target" }; - } - - @_ = ( - $class, - sub { - # Perls compiled with THREADS_HAVE_PIDS do not copy end_av properly - # between threads, so B::end_av ends up returning a B::SPECIAL and it - # goes downhill from there - # Install a noop END just to be on the safe side - { local $@; eval 'END {}' } - $add_endblock->(); - goto $target - }, - @_, - ); - - goto $orig_create; - }; - - $before_is_installed = 1; -} - -# just in case threads got loaded after us (silly) -sub CLONE { - unless ($before_is_installed) { - require Carp; - Carp::croak("You must load the 'threads' module before @{[ __PACKAGE__ ]}"); + # internally, PL_main_start is nulled immediately before entering global destruction + # and we can use B to detect that. It will also be null before the main runloop starts, + # so we check install a CHECK if needed to detect that. + require B; + my $started = !B::main_start()->isa(q[B::NULL]); + unless ($started) { + eval 'CHECK { $started = 1 }; 1' + or die $@; } -} - -1; # keep eval happy - -PP_IGD - + eval 'sub in_global_destruction () { $started && B::main_start()->isa(q[B::NULL]) }; 1' + or die $@; } 1; # keep require happy