X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDevel%2FGlobalDestruction.pm;h=97eedd0e56c13d23eb60b51a50dc808d6980f217;hb=09b1281346cf3f556c319aed994f0dd305eaad63;hp=5507824ecd22f263e48cdab629aca9b45c07f952;hpb=78be2b4a5f7971e996f688e20ae18d3e7e4931db;p=p5sagit%2FDevel-GlobalDestruction.git

diff --git a/lib/Devel/GlobalDestruction.pm b/lib/Devel/GlobalDestruction.pm
index 5507824..97eedd0 100644
--- a/lib/Devel/GlobalDestruction.pm
+++ b/lib/Devel/GlobalDestruction.pm
@@ -3,68 +3,126 @@ package Devel::GlobalDestruction;
 use strict;
 use warnings;
 
-our $VERSION = '0.07';
+our $VERSION = '0.09';
 
-use Sub::Exporter -setup => {
-    exports => [ qw(in_global_destruction) ],
-    groups  => { default => [ -all ] },
+use Sub::Exporter::Progressive -setup => {
+  exports => [ qw(in_global_destruction) ],
+  groups  => { default => [ -all ] },
 };
 
 # we run 5.14+ - everything is in core
 #
 if (defined ${^GLOBAL_PHASE}) {
-    eval 'sub in_global_destruction () { ${^GLOBAL_PHASE} eq q[DESTRUCT] }';
+  eval 'sub in_global_destruction () { ${^GLOBAL_PHASE} eq q[DESTRUCT] }; 1'
+    or die $@;
 }
 # try to load the xs version if it was compiled
 #
 elsif (eval {
-    require XSLoader;
-    XSLoader::load(__PACKAGE__, $VERSION);
-    1;
+  require XSLoader;
+  XSLoader::load(__PACKAGE__, $VERSION);
+  1;
 }) {
-    # the eval already installed everything, nothing to do
+  # the eval already installed everything, nothing to do
 }
-# Not core nor XS
+# We need pure-perl and we are running under -c
+# None of the END-block trickery will work, use a global scope guard instead,
+# as it is more than adequate in this situation
+# The whole thing is in an eval to prevent perl from parsing it in the
+# first place where none of this is needed
 #
-else {
+elsif ($^C) {
+  eval <<'PP_IGD' or die $@;
+
+  my $in_global_destruction;
+
+  sub in_global_destruction () { $in_global_destruction }
+
+  {
+    package Devel::GlobalDestgruction::_MinusC::ScopeGuard;
+    sub DESTROY { shift->[0]->() };
+  }
 
-  # 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;
+  no warnings 'once';
+  $Devel::GlobalDestgruction::_MinusC::guard = bless [sub {
+    $in_global_destruction = 1;
+  }], 'Devel::GlobalDestgruction::_MinusC::ScopeGuard';
 
+  1; # keep eval happy
+
+PP_IGD
+}
+# 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 { $in_global_destruction = 1 };
+};
+
 # This block will fire towards the end of the program execution
-# Since there is no way for us to generate an END which will execute *last*
-# this is *NOT 100% INCOMPATIBLE* with XS/${^GLOBAL_PHASE}. We *may* end up
-# with a true in_gloal_destruction() in the middle of another END block
-# There are no practical cases where this matters.
+# 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 {
-  $in_global_destruction = 1;
-}
+END { $add_endblock->() }
 
 # threads do not execute the global ENDs (it would be stupid). However
-# one can register a new END via simple string eval within a thread, and
+# 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 evaled in a CLONE is ignored :(
+# 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 {
-    { local $@; eval 'END { $in_global_destruction = 1 }' };
+    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;
 }
 
@@ -119,7 +177,8 @@ destruction is in effect.
 
 =head1 EXPORTS
 
-This module uses L<Sub::Exporter> so the exports may be renamed, aliased, etc.
+This module uses L<Sub::Exporter::Progressive> so the exports may be renamed,
+aliased, etc. if L<Sub::Exporter> is present.
 
 =over 4
 
@@ -141,6 +200,10 @@ Jesse Luehrs E<lt>doy@tozt.netE<gt>
 
 Peter Rabbitson E<lt>ribasushi@cpan.orgE<gt>
 
+Arthur Axel 'fREW' Schmidt E<lt>frioux@gmail.comE<gt>
+
+Elizabeth Mattijsen E<lt>liz@dijkmat.nlE<gt>
+
 =head1 COPYRIGHT
 
     Copyright (c) 2008 Yuval Kogman. All rights reserved