+package Lexical::Types::TestThreads;
+
+use strict;
+use warnings;
+
+use Config qw<%Config>;
+
+use VPIT::TestHelpers;
+
+sub import {
+ shift;
+
+ require Lexical::Types;
+
+ skip_all 'This Lexical::Types isn\'t thread safe'
+ unless Lexical::Types::LT_THREADSAFE();
+
+ my $force = $ENV{PERL_LEXICAL_TYPES_TEST_THREADS} ? 1 : !1;
+ skip_all 'This perl wasn\'t built to support threads'
+ unless $Config{useithreads};
+ skip_all 'perl 5.13.4 required to test thread safety'
+ unless $force or "$]" >= 5.013004;
+
+ load_or_skip('threads', $force ? '0' : '1.67', [ ],
+ 'required to test thread safety');
+
+ my %exports = (
+ spawn => \&spawn,
+ );
+
+ my $pkg = caller;
+ while (my ($name, $code) = each %exports) {
+ no strict 'refs';
+ *{$pkg.'::'.$name} = $code;
+ }
+}
+
+sub spawn {
+ local $@;
+ my @diag;
+ my $thread = eval {
+ local $SIG{__WARN__} = sub { push @diag, "Thread creation warning: @_" };
+ threads->create(@_);
+ };
+ push @diag, "Thread creation error: $@" if $@;
+ if (@diag) {
+ require Test::Leaner;
+ Test::Leaner::diag($_) for @diag;
+ }
+ return $thread ? $thread : ();
+}
+
+1;