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1 | package Devel::GlobalDestruction; |
2 | |
3 | use strict; |
4 | use warnings; |
5 | |
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6 | our $VERSION = '0.11'; |
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7 | |
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8 | use Sub::Exporter::Progressive -setup => { |
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9 | exports => [ qw(in_global_destruction) ], |
10 | groups => { default => [ -all ] }, |
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11 | }; |
12 | |
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13 | # we run 5.14+ - everything is in core |
14 | # |
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15 | if (defined ${^GLOBAL_PHASE}) { |
62376bb4 |
16 | eval 'sub in_global_destruction () { ${^GLOBAL_PHASE} eq q[DESTRUCT] }; 1' |
17 | or die $@; |
3790e928 |
18 | } |
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19 | # try to load the xs version if it was compiled |
20 | # |
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21 | elsif (eval { |
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22 | require Devel::GlobalDestruction::XS; |
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23 | no warnings 'once'; |
b1bee216 |
24 | *in_global_destruction = \&Devel::GlobalDestruction::XS::in_global_destruction; |
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25 | 1; |
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26 | }) { |
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27 | # the eval already installed everything, nothing to do |
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28 | } |
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29 | else { |
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30 | # internally, PL_main_start is nulled immediately before entering global destruction |
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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. |
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33 | require B; |
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34 | my $started = !B::main_start()->isa(q[B::NULL]); |
35 | unless ($started) { |
d4be4bd8 |
36 | # work around 5.6 eval bug |
37 | eval '0 && $started; CHECK { $started = 1 }; 1' |
5629eb97 |
38 | or die $@; |
39 | } |
d4be4bd8 |
40 | eval '0 && $started; sub in_global_destruction () { $started && B::main_start()->isa(q[B::NULL]) }; 1' |
97415ced |
41 | or die $@; |
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42 | } |
43 | |
44 | 1; # keep require happy |
45 | |
46 | |
47 | __END__ |
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48 | |
49 | =head1 NAME |
50 | |
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51 | Devel::GlobalDestruction - Provides function returning the equivalent of |
52 | C<${^GLOBAL_PHASE} eq 'DESTRUCT'> for older perls. |
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53 | |
54 | =head1 SYNOPSIS |
55 | |
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56 | package Foo; |
57 | use Devel::GlobalDestruction; |
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58 | |
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59 | use namespace::clean; # to avoid having an "in_global_destruction" method |
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60 | |
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61 | sub DESTROY { |
62 | return if in_global_destruction; |
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63 | |
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64 | do_something_a_little_tricky(); |
65 | } |
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66 | |
67 | =head1 DESCRIPTION |
68 | |
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. |
71 | |
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. |
75 | |
76 | For these constructors you can avoid the mess by simply bailing out if global |
77 | destruction is in effect. |
78 | |
79 | =head1 EXPORTS |
80 | |
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81 | This module uses L<Sub::Exporter::Progressive> so the exports may be renamed, |
82 | aliased, etc. if L<Sub::Exporter> is present. |
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83 | |
84 | =over 4 |
85 | |
86 | =item in_global_destruction |
87 | |
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88 | Returns true if the interpreter is in global destruction. In perl 5.14+, this |
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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>. |
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91 | |
92 | =back |
93 | |
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94 | =head1 AUTHORS |
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95 | |
96 | Yuval Kogman E<lt>nothingmuch@woobling.orgE<gt> |
97 | |
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98 | Florian Ragwitz E<lt>rafl@debian.orgE<gt> |
99 | |
aaa7f60f |
100 | Jesse Luehrs E<lt>doy@tozt.netE<gt> |
101 | |
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102 | Peter Rabbitson E<lt>ribasushi@cpan.orgE<gt> |
103 | |
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104 | Arthur Axel 'fREW' Schmidt E<lt>frioux@gmail.comE<gt> |
105 | |
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106 | Elizabeth Mattijsen E<lt>liz@dijkmat.nlE<gt> |
107 | |
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108 | Greham Knop E<lt>haarg@haarg.orgE<gt> |
109 | |
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110 | =head1 COPYRIGHT |
111 | |
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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. |
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115 | |
116 | =cut |