X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=pod%2Fperlthrtut.pod;h=6a47e109375fed1f07232c5a755f3c1a2f00a4d2;hb=bdcfa4c71f2cdcdbe5f7cfb1837da43d4adcc767;hp=8bcbf24913194d049be9a66cb8254dc95adc5f67;hpb=7830a95b315d7bb2736bca349d04df713036a763;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/pod/perlthrtut.pod b/pod/perlthrtut.pod
index 8bcbf24..6a47e10 100644
--- a/pod/perlthrtut.pod
+++ b/pod/perlthrtut.pod
@@ -955,6 +955,16 @@ be little different than ordinary code.
 Also note that under the current implementation, shared variables
 use a little more memory and are a little slower than ordinary variables.
 
+=head1 Threadsafety of System Libraries
+
+Whether various library calls are threadsafe is outside the control
+of Perl.  Calls often suffering from not being threadsafe include
+localtime(), gmtime(), get{gr,host,net,proto,serv,pw}*(), readdir(),
+rand(), srand().  If the system Perl is compiled in has threadsafe
+variants of these calls, they will be used, but besides that, Perl is
+at the mercy of the thread safety or unsafety of the calls.  Please
+consult your C library call documentation.
+
 =head1 Conclusion
 
 A complete thread tutorial could fill a book (and has, many times),