+sub init_threads {
+ my ($pkg, $threadsafe, $force_var) = @_;
+
+ $pkg = 'package' unless defined $pkg;
+ skip_all "This $pkg isn't thread safe" if defined $threadsafe and !$threadsafe;
+
+ skip_all 'This perl wasn\'t built to support threads'
+ unless $Config::Config{useithreads};
+
+ $force_var = 'PERL_FORCE_TEST_THREADS' unless defined $force_var;
+ my $force = $ENV{$force_var} ? 1 : !1;
+ skip_all 'perl 5.13.4 required to test thread safety'
+ unless $force or "$]" >= 5.013_004;
+
+ load_or_skip_all 'threads', $force ? '0' : '1.67', [ ];
+ load_or_skip_all 'threads::shared', $force ? '0' : '1.14', [ ];
+
+ require Test::Leaner;
+
+ diag "Threads testing forced by \$ENV{$force_var}" if $force;
+
+ return spawn => \&spawn;
+}
+