I_THREADSAFE ought to be true when PERL_INDIRECT_PM_DISABLE is set

[perl/modules/indirect.git] / lib / indirect.pm

diff --git a/lib/indirect.pm b/lib/indirect.pm
index 6e99ebaf06b7ae490e2911b884edf7894bfa8b5a..7c2bab120e97667ef656be5f767e279efa1ab440 100644 (file)
--- a/lib/indirect.pm
+++ b/lib/indirect.pm
@@ -11,13 +11,13 @@ indirect - Lexically warn about using the indirect object syntax.
 
 =head1 VERSION
 
-Version 0.16
+Version 0.18
 
 =cut
 
 our $VERSION;
 BEGIN {
- $VERSION = '0.16';
+ $VERSION = '0.18';
 }
 
 =head1 SYNOPSIS
@@ -58,8 +58,13 @@ This module is B<not> a source filter.
 =cut
 
 BEGIN {
- require XSLoader;
- XSLoader::load(__PACKAGE__, $VERSION);
+ if ($ENV{PERL_INDIRECT_PM_DISABLE}) {
+  *_tag = sub ($) { 1 };
+  *I_THREADSAFE = sub () { 1 };
+ } else {
+  require XSLoader;
+  XSLoader::load(__PACKAGE__, $VERSION);
+ }
 }
 
 =head1 METHODS
@@ -153,6 +158,17 @@ The default warning/exception message thrown when an indirect call on an object
 
 The default warning/exception message thrown when an indirect call on a block is found.
 
+=head1 ENVIRONMENT
+
+=head2 C<PERL_INDIRECT_PM_DISABLE>
+
+If this environment variable is set to true when the pragma is used for the first time, the XS code won't be loaded and, although the C<'indirect'> lexical hint will be set to true in the scope of use, the pragma itself won't do anything.
+In this case, the pragma will always be considered to be thread-safe, and as such L</I_THREADSAFE> will be true.
+This is useful for disabling C<indirect> in production environments.
+
+Note that clearing this variable after C<indirect> was loaded has no effect.
+If you want to reenable the pragma later, you also need to reload it by deleting the C<'indirect.pm'> entry from C<%INC>.
+
 =head1 CAVEATS
 
 The implementation was tweaked to work around several limitations of vanilla C<perl> pragmas : it's thread safe, and doesn't suffer from a C<perl 5.8.x-5.10.0> bug that causes all pragmas to propagate into C<require>d scopes.