ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/Devel-FindRef/FindRef.pm
(Generate patch)

Comparing Devel-FindRef/FindRef.pm (file contents):
Revision 1.5 by root, Wed Feb 7 21:34:02 2007 UTC vs.
Revision 1.18 by root, Mon Dec 1 13:22:43 2008 UTC

1package Devel::FindRef; 1package Devel::FindRef;
2 2
3no warnings; # I hate warning nazis
3use strict; 4use strict;
4 5
5use XSLoader; 6use XSLoader;
6 7use Scalar::Util;
7 8
8BEGIN { 9BEGIN {
9 our $VERSION = '0.2'; 10 our $VERSION = '1.31';
10 XSLoader::load __PACKAGE__, $VERSION; 11 XSLoader::load __PACKAGE__, $VERSION;
11} 12}
12 13
13=head1 NAME 14=head1 NAME
14 15
15Devel::FindRef - where is that reference to my scalar hiding? 16Devel::FindRef - where is that reference to my variable hiding?
16 17
17=head1 SYNOPSIS 18=head1 SYNOPSIS
18 19
19 use Devel::FindRef; 20 use Devel::FindRef;
21
22 print Devel::FindRef::track \$some_variable;
20 23
21=head1 DESCRIPTION 24=head1 DESCRIPTION
22 25
23Tracking down reference problems (e.g. you expect some object to be 26Tracking down reference problems (e.g. you expect some object to be
24destroyed, but there are still references to it that keep it alive) can be 27destroyed, but there are still references to it that keep it alive) can be
… …
45 testsub; 48 testsub;
46 49
47The output is as follows (or similar to this, in case I forget to update 50The output is as follows (or similar to this, in case I forget to update
48the manpage after some changes): 51the manpage after some changes):
49 52
50 SCALAR(0x676fa0) is 53 SCALAR(0x814ece8) is
54 +- in the global $Test::var.
51 referenced by REF(0x676fb0), which is 55 +- referenced by REF(0x814f9e4), which is
52 in the lexical '$x' in CODE(0x676370), which is 56 | in the lexical '$x' in CODE(0x814ed78), which is
53 not found anywhere I looked :( 57 | the containing scope for CODE(0x820c4b0), which is
58 | in the global &Test::testsub.
54 referenced by REF(0x676360), which is 59 +- referenced by REF(0x814ed6c), which is
55 in the member 'ukukey' of HASH(0x756660), which is 60 | in the member 'ukukey' of HASH(0x81da20c), which is
56 in the global %Test::hash. 61 | in the global %Test::hash.
57 in the global $Test::var.
58 referenced by REF(0x6760e0), which is 62 +- referenced by REF(0x814ec28), which is
63 | not found anywhere I looked :(
64 +- referenced by REF(0x814eb44), which is
59 in the member 'ukukey2' of HASH(0x676f30), which is 65 in the member 'ukukey2' of HASH(0x814f99c), which is
60 referenced by REF(0x77bcf0), which is 66 +- referenced by REF(0x820c450), which is
61 in the lexical '$local' in CODE(0x77bcb0), which is 67 | in the lexical '$local' in CODE(0x820c4b0), which was seen before.
62 in the global &Test::testsub.
63 referenced by REF(0x77bc80), which is 68 +- referenced by REF(0x820c204), which is
64 in the global $Test::hash2. 69 in the global $Test::hash2.
65
66 70
67It is a bit convoluted to read, but basically it says that the value 71It is a bit convoluted to read, but basically it says that the value
68stored in C<$var> can be found: 72stored in C<$var> can be found:
69 73
70=over 4 74=over 4
… …
78 82
79=item - in the hash element C<ukukey2>, in the hash in the my variable 83=item - in the hash element C<ukukey2>, in the hash in the my variable
80C<$local> in the sub C<Test::testsub> and also in the hash referenced by 84C<$local> in the sub C<Test::testsub> and also in the hash referenced by
81C<$Test::hash2>. 85C<$Test::hash2>.
82 86
87=back
88
83=head1 EXPORTS 89=head1 EXPORTS
84 90
85None. 91None.
86 92
87=head1 FUNCTIONS 93=head1 FUNCTIONS
… …
98 104
99=cut 105=cut
100 106
101sub find($); 107sub find($);
102 108
109sub _f($) {
110 "$_[0] [refcount " . (_refcnt $_[0]) . "]"
111}
112
103sub track { 113sub track {
114 my ($ref, $depth) = @_;
115 @_ = ();
116
104 my $buf = ""; 117 my $buf = "";
118 my %seen;
119
120 Scalar::Util::weaken $ref;
105 121
106 my $track; $track = sub { 122 my $track; $track = sub {
107 my (undef, $depth, $indent) = @_; 123 my ($refref, $depth, $indent) = @_;
108 124
109 if ($depth) { 125 if ($depth) {
110 my (@about) = find $_[0]; 126 my (@about) = find $$refref;
111 if (@about) { 127 if (@about) {
112 for my $about (@about) { 128 for my $about (@about) {
113 $buf .= (" ") x $indent; 129 $buf .= "$indent" . (@about > 1 ? "+- " : " ") . $about->[0];
114 $buf .= $about->[0];
115 if (@$about > 1) { 130 if (@$about > 1) {
131 if ($seen{ref2ptr $about->[1]}++) {
132 $buf .= " " . (_f $about->[1]) . ", which was seen before.\n";
133 } else {
116 $buf .= " $about->[1], which is\n"; 134 $buf .= " " . (_f $about->[1]) . ", which is\n";
117 $track->($about->[1], $depth - 1, $indent + 1); 135 $track->(\$about->[1], $depth - 1, $about == $about[-1] ? "$indent " : "$indent| ");
136 }
118 } else { 137 } else {
119 $buf .= ".\n"; 138 $buf .= ".\n";
120 } 139 }
121 } 140 }
122 } else { 141 } else {
123 $buf .= (" ") x $indent;
124 $buf .= "not found anywhere I looked :(\n"; 142 $buf .= "$indent not found anywhere I looked :(\n";
125 } 143 }
126 } else { 144 } else {
127 $buf .= (" ") x $indent;
128 $buf .= "not referenced within the search depth.\n"; 145 $buf .= "$indent not referenced within the search depth.\n";
129 } 146 }
130 }; 147 };
131 148
132 $buf .= "$_[0] is\n"; 149 $buf .= (_f $ref) . " is\n";
133 $track->($_[0], $_[1] || 10, 1); 150 $track->(\$ref, $depth || $ENV{PERL_DEVEL_FINDREF_DEPTH} || 10, "");
134 $buf 151 $buf
135} 152}
136 153
137=item @references = Devel::FindRef::find $ref 154=item @references = Devel::FindRef::find $ref
138 155
139Return arrayrefs that contain [$message, $ref] pairs. The message 156Return arrayrefs that contain [$message, $ref] pairs. The message
140describes what kind of reference was found and the C<$ref> is the 157describes what kind of reference was found and the C<$ref> is the
141reference itself, which cna be omitted if C<find> decided to end the 158reference itself, which can be omitted if C<find> decided to end the
142search. 159search. The returned references are all weak references.
143 160
144The C<track> function uses this to find references to the value you are 161The C<track> function uses this to find references to the value you are
145interested in and recurses on the returned references. 162interested in and recurses on the returned references.
146 163
147=cut 164=cut
148 165
149sub find($) { 166sub find($) {
150 my ($about, $excl) = &find_; 167 my ($about, $excl) = &find_;
151 my %excl = map +($_ => 1), @$excl; 168 my %excl = map +($_ => undef), @$excl;
152 grep !$excl{$_->[1] + 0}, @$about 169 grep !exists $excl{ref2ptr $_->[1]}, @$about
153} 170}
154 171
155=item $ref = Devel::FindRef::ref2ptr $ptr 172=item $ref = Devel::FindRef::ptr2ref $integer
156 173
157Sometimes you know (from debugging output) the address of a perl scalar 174Sometimes you know (from debugging output) the address of a perl scalar
158you are interested in. This function can be used to turn the address into 175you are interested in (e.g. C<HASH(0x176ff70)>). This function can be used
159a reference to that scalar. It is quite safe to call on valid addresses, 176to turn the address into a reference to that scalar. It is quite safe to
160but extremely dangerous to call on invalid ones. 177call on valid addresses, but extremely dangerous to call on invalid ones.
178
179 # we know that HASH(0x176ff70) exists, so turn it into a hashref:
180 my $ref_to_hash = Devel::FindRef::ptr2ref 0x176ff70;
181
182=item $ref = Devel::FindRef::ref2ptr $reference
183
184The opposite of C<ptr2ref>, above: returns the internal address of the
185value pointed to by the passed reference. I<No checks whatsoever will be
186done>, so don't use this.
161 187
162=back 188=back
163 189
190=head1 ENVIRONMENT VARIABLES
191
192You can set the environment variable C<PERL_DEVEL_FINDREF_DEPTH> to an
193integer to override the default depth in C<track>. If a call explicitly
194specified a depth it is not overridden.
195
164=head1 AUTHOR 196=head1 AUTHOR
165 197
166Marc Lehmann <pcg@goof.com>. 198Marc Lehmann <pcg@goof.com>.
167 199
168=head1 BUGS
169
170Only code values, arrays, hashes, scalars and magic are being looked at.
171
172This is a quick hack only.
173
174=head1 COPYRIGHT AND LICENSE 200=head1 COPYRIGHT AND LICENSE
175 201
176Copyright (C) 2007 by Marc Lehmann. 202Copyright (C) 2007, 2008 by Marc Lehmann.
177 203
178This library is free software; you can redistribute it and/or modify 204This library is free software; you can redistribute it and/or modify
179it under the same terms as Perl itself, either Perl version 5.8.8 or, 205it under the same terms as Perl itself, either Perl version 5.8.8 or,
180at your option, any later version of Perl 5 you may have available. 206at your option, any later version of Perl 5 you may have available.
181 207

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines