1 package Devel::GlobalDestruction;
8 use Sub::Exporter::Progressive -setup => {
9 exports => [ qw(in_global_destruction) ],
10 groups => { default => [ -all ] },
13 # we run 5.14+ - everything is in core
15 if (defined ${^GLOBAL_PHASE}) {
16 eval 'sub in_global_destruction () { ${^GLOBAL_PHASE} eq q[DESTRUCT] }; 1'
19 # try to load the xs version if it was compiled
22 require Devel::GlobalDestruction::XS;
24 *in_global_destruction = \&Devel::GlobalDestruction::XS::in_global_destruction;
27 # the eval already installed everything, nothing to do
30 # internally, PL_main_start is nulled immediately before entering global destruction
31 # and we can use B to detect that. It will also be null before the main runloop starts,
32 # so we check install a CHECK if needed to detect that.
34 my $started = !B::main_start()->isa(q[B::NULL]);
36 # work around 5.6 eval bug
37 eval '0 && $started; CHECK { $started = 1 }; 1'
40 eval '0 && $started; sub in_global_destruction () { $started && B::main_start()->isa(q[B::NULL]) }; 1'
44 1; # keep require happy
51 Devel::GlobalDestruction - Provides function returning the equivalent of
52 C<${^GLOBAL_PHASE} eq 'DESTRUCT'> for older perls.
57 use Devel::GlobalDestruction;
59 use namespace::clean; # to avoid having an "in_global_destruction" method
62 return if in_global_destruction;
64 do_something_a_little_tricky();
69 Perl's global destruction is a little tricky to deal with WRT finalizers
70 because it's not ordered and objects can sometimes disappear.
72 Writing defensive destructors is hard and annoying, and usually if global
73 destruction is happenning you only need the destructors that free up non
74 process local resources to actually execute.
76 For these constructors you can avoid the mess by simply bailing out if global
77 destruction is in effect.
81 This module uses L<Sub::Exporter::Progressive> so the exports may be renamed,
82 aliased, etc. if L<Sub::Exporter> is present.
86 =item in_global_destruction
88 Returns true if the interpreter is in global destruction. In perl 5.14+, this
89 returns C<${^GLOBAL_PHASE} eq 'DESTRUCT'>, and on earlier perls, detects it using
90 the value of C<PL_main_start> or C<PL_dirty>.
96 Yuval Kogman E<lt>nothingmuch@woobling.orgE<gt>
98 Florian Ragwitz E<lt>rafl@debian.orgE<gt>
100 Jesse Luehrs E<lt>doy@tozt.netE<gt>
102 Peter Rabbitson E<lt>ribasushi@cpan.orgE<gt>
104 Arthur Axel 'fREW' Schmidt E<lt>frioux@gmail.comE<gt>
106 Elizabeth Mattijsen E<lt>liz@dijkmat.nlE<gt>
108 Greham Knop E<lt>haarg@haarg.orgE<gt>
112 Copyright (c) 2008 Yuval Kogman. All rights reserved
113 This program is free software; you can redistribute
114 it and/or modify it under the same terms as Perl itself.