apply Net::Ping patch that makes the fork()-based approach

[perl5.git] / lib / Thread.pm

diff --git a/lib/Thread.pm b/lib/Thread.pm
index d3e27e1..c9f05c0 100644 (file)
--- a/lib/Thread.pm
+++ b/lib/Thread.pm
@@ -1,13 +1,11 @@
 package Thread;
 
-$VERSION = '2.00';
-
 use strict;
 
-our $ithreads;
-our $othreads;
+our($VERSION, $ithreads, $othreads);
 
 BEGIN {
+    $VERSION = '2.00';
     use Config;
     $ithreads = $Config{useithreads};
     $othreads = $Config{use5005threads};
@@ -15,13 +13,13 @@ BEGIN {
 
 require Exporter;
 use XSLoader ();
-our($VERSION, @ISA, @EXPORT, @EXPORT_OK);
+our(@ISA, @EXPORT, @EXPORT_OK);
 
 @ISA = qw(Exporter);
 
 BEGIN {
     if ($ithreads) {
-       @EXPORT = qw(share cond_wait cond_broadcast cond_signal unlock)
+       @EXPORT = qw(cond_wait cond_broadcast cond_signal)
     } elsif ($othreads) {
        @EXPORT_OK = qw(cond_signal cond_broadcast cond_wait);
     }
@@ -30,7 +28,7 @@ BEGIN {
 
 =head1 NAME
 
-Thread - manipulate threads in Perl
+Thread - manipulate threads in Perl (for old code only)
 
 =head1 CAVEAT
 
@@ -52,15 +50,24 @@ In Perl 5.8 the ithreads model became available through the C<threads>
 module.
 
 Neither model is configured by default into Perl (except, as mentioned
-above, in Win32 ithreads are always available.)
+above, in Win32 ithreads are always available.)  You can see your
+Perl's threading configuration by running C<perl -V> and looking for
+the I<use...threads> variables, or inside script by C<use Config;>
+and testing for C<$Config{use5005threads}> and C<$Config{useithreads}>.
+
+For old code and interim backwards compatibility, the Thread module
+has been reworked to function as a frontend for both 5005threads and
+ithreads.
 
-For backwards compatibility, the Thread module has been reworked
-to function as a frontend for both 5005threads and ithreads.
 Note that the compatibility is not complete: because the data sharing
 models are directly opposed, anything to do with data sharing has to
 be thought differently.  With the ithreads you must explicitly share()
 variables between the threads.
 
+For new code the use of the C<Thread> module is discouraged and
+the direct use of the C<threads> and C<threads::shared> modules
+is encouraged instead.
+
 Finally, note that there are many known serious problems with the
 5005threads, one of the least of which is that regular expression
 match variables like $1 are not threadsafe, that is, they easily get
@@ -100,8 +107,6 @@ use ithreads instead.
 
     my @list = Thread->list;   # not available with ithreads
 
-    unlock(...);       # not available with the 5.005 threads
-
     use Thread 'async';
 
 =head1 DESCRIPTION
@@ -125,8 +130,7 @@ thread.
 
 =item lock VARIABLE
 
-C<lock> places a lock on a variable until the lock goes out of scope
-(with ithreads you can also explicitly unlock()).
+C<lock> places a lock on a variable until the lock goes out of scope.
 
 If the variable is locked by another thread, the C<lock> call will
 block until it's available.  C<lock> is recursive, so multiple calls
@@ -306,23 +310,27 @@ sub unimplement {
 
 BEGIN {
     if ($ithreads) {
+       if ($othreads) {
+           require Carp;
+           Carp::croak("This Perl has both ithreads and 5005threads (serious malconfiguration)");
+       }
        XSLoader::load 'threads';
-       for my $m (qw(new join detach yield self tid equal)) {
+       for my $m (qw(new join detach yield self tid equal list)) {
            no strict 'refs';
            *{"Thread::$m"} = \&{"threads::$m"};
        }
-       XSLoader::load 'threads::shared';
-       for my $m (qw(cond_signal cond_broadcast cond_wait unlock share)) {
+       require 'threads/shared.pm';
+       for my $m (qw(cond_signal cond_broadcast cond_wait)) {
            no strict 'refs';
            *{"Thread::$m"} = \&{"threads::shared::${m}_enabled"};
        }
-       unimplement(qw(list done eval flags));
+       # trying to unimplement eval gives redefined warning
+       unimplement(qw(done flags));
     } elsif ($othreads) {
        XSLoader::load 'Thread';
-       unimplement(qw(unlock));
     } else {
        require Carp;
-       Carp::croak("This Perl has neither ithreads not 5005threads");
+       Carp::croak("This Perl has neither ithreads nor 5005threads");
     }
 }