Replace our implementation of realpath() with OpenBSD's

[p5sagit/p5-mst-13.2.git] / pod / perlmod.pod

diff --git a/pod/perlmod.pod b/pod/perlmod.pod
index a9a8756..29ad67c 100644 (file)
--- a/pod/perlmod.pod
+++ b/pod/perlmod.pod
@@ -61,8 +61,8 @@ as a pattern match, a substitution, or a transliteration.
 Variables beginning with underscore used to be forced into package
 main, but we decided it was more useful for package writers to be able
 to use leading underscore to indicate private variables and method names.
-$_ is still global though.  See also L<perlvar/"Technical Note on the
-Syntax of Variable Names">.
+$_ is still global though.  See also
+L<perlvar/"Technical Note on the Syntax of Variable Names">.
 
 C<eval>ed strings are compiled in the package in which the eval() was
 compiled.  (Assignments to C<$SIG{}>, however, assume the signal
@@ -310,6 +310,10 @@ create a file called F<Some/Module.pm> and start with this template:
     }
     our @EXPORT_OK;
 
+    # exported package globals go here
+    our $Var1;
+    our %Hashit;
+
     # non-exported package globals go here
     our @more;
     our $stuff;
@@ -439,6 +443,23 @@ the module.  It is the responsibility of the F<.pm> file to load
 although the POSIX module happens to do both dynamic loading and
 autoloading, the user can say just C<use POSIX> to get it all.
 
+=head2 Making your module threadsafe
+
+Perl has since 5.6.0 support for a new type of threads called
+interpreter threads. These threads can be used explicitly and implicitly.
+
+Ithreads work by cloning the data tree so that no data is shared
+between different threads. These threads can be used using the threads
+module or by doing fork() on win32 (fake fork() support). When a thread is
+cloned all perl data is cloned, however non perl data cannot be cloned.
+Perl after 5.7.2 has support for the C<CLONE> keyword. C<CLONE> will be
+executed once for every package that has it defined (or inherits it).
+It will be called in the context of the new thread, so all modifications
+are made in the new area.
+
+If you want to CLONE all objects you will need to keep track of them per
+package. This is simply done using a hash and Scalar::Util::weaken().
+
 =head1 SEE ALSO
 
 See L<perlmodlib> for general style issues related to building Perl