Merge branch 'master' into topic/constructor_rewrite

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / GlobalDestruction.pm

diff --git a/lib/DBIx/Class/GlobalDestruction.pm b/lib/DBIx/Class/GlobalDestruction.pm
new file mode 100644 (file)
index 0000000..33a9654
--- /dev/null
+++ b/lib/DBIx/Class/GlobalDestruction.pm
@@ -0,0 +1,64 @@
+# This is just a concept-test. If works as intended will ship in its own
+# right as Devel::GlobalDestruction::PP or perhaps even as part of rafls
+# D::GD itself
+
+package # hide from pause
+  DBIx::Class::GlobalDestruction;
+
+use strict;
+use warnings;
+
+use base 'Exporter';
+our @EXPORT = 'in_global_destruction';
+
+use DBIx::Class::Exception;
+
+if (defined ${^GLOBAL_PHASE}) {
+  eval 'sub in_global_destruction () { ${^GLOBAL_PHASE} eq q[DESTRUCT] }';
+}
+elsif (eval { require Devel::GlobalDestruction }) { # use the XS version if available
+  *in_global_destruction = \&Devel::GlobalDestruction::in_global_destruction;
+}
+else {
+  my ($in_global_destruction, $before_is_installed);
+
+  eval <<'PP_IGD';
+
+sub in_global_destruction () { $in_global_destruction }
+
+END {
+  # SpeedyCGI runs END blocks every cycle but keeps object instances
+  # hence we have to disable the globaldestroy hatch, and rely on the
+  # eval traps (which appears to work, but are risky done so late)
+  $in_global_destruction = 1 unless $CGI::SpeedyCGI::i_am_speedy;
+}
+
+# threads do not execute the global ENDs (it would be stupid). However
+# one can register a new END via simple string eval within a thread, and
+# achieve the same result. A logical place to do this would be CLONE, which
+# is claimed to run in the context of the new thread. However this does
+# not really seem to be the case - any END evaled in a CLONE is ignored :(
+# Hence blatantly hooking threads::create
+if ($INC{'threads.pm'}) {
+  require Class::Method::Modifiers;
+  Class::Method::Modifiers::install_modifier( threads => before => create => sub {
+    my $orig_target_cref = $_[1];
+    $_[1] = sub {
+      { local $@; eval 'END { $in_global_destruction = 1 }' }
+      $orig_target_cref->();
+    };
+  });
+  $before_is_installed = 1;
+}
+
+# just in case threads got loaded after DBIC (silly)
+sub CLONE {
+  DBIx::Class::Exception->throw("You must load the 'threads' module before @{[ __PACKAGE__ ]}")
+    unless $before_is_installed;
+}
+
+PP_IGD
+
+}
+
+1;