--- Compress-LZF/perlmulticore.h	2015/06/28 17:40:38	1.2
+++ Compress-LZF/perlmulticore.h	2015/06/29 23:51:28	1.3
@@ -36,7 +36,7 @@
 The newest version of this document can be found at
 L<http://pod.tst.eu/http://cvs.schmorp.de/Coro-Multicore/perlmulticore.h>.
 
-The nwest version of the header fgile itself, which
+The newest version of the header file itself, which
 includes this documentation, can be downloaded from
 L<http://cvs.schmorp.de/Coro-Multicore/perlmulticore.h>.
 
@@ -120,7 +120,7 @@
        // error, assume lock is held by another process and do it the slow way
        perlinterp_release ();
        res = fcntl (fd, F_SETLKW, &flock);
-       perlinterp_release ();
+       perlinterp_acquire ();
      }
 
 =head1 THE HARD AND FAST RULES
@@ -200,10 +200,6 @@
    pthread_mutex_unlock (&my_mutex);
    perlinterp_acquire ();
 
-This isn't as trivial as it looks though, as you need to find out which
-threading system is in use (with L<Coro::Multicore>, it currently is
-always pthreads).
-
 =item I<Don't> get confused by having to release first.
 
 In many real world scenarios, you acquire a resource, do something, then
@@ -306,19 +302,48 @@
 
 =back
 
+
+=head1 DISABLING PERL MULTICORE AT COMPILE TIME
+
+You can disable the complete perl multicore API by defining the
+symbol C<PERL_MULTICORE_DISABLE> to C<1> (e.g. by specifying
+F<-DPERL_MULTICORE_DISABLE> as compiler argument).
+
+This will leave no traces of the API in the compiled code, suitable
+"empty" C<perl_release> and C<perl_acquire> definitions will be provided.
+
+This could be added to perl's C<CPPFLAGS> when configuring perl on
+platforms that do not support threading at all for example.
+
+
 =head1 AUTHOR
 
    Marc A. Lehmann <perlmulticore@schmorp.de>
+   http://perlmulticore.schmorp.de/
 
 =head1 LICENSE
 
-The F<perlmulticore.h> is put into the public domain. Where this is legally
-not possible, or at your option, it can be licensed under creativecommons
-CC0 license: L<https://creativecommons.org/publicdomain/zero/1.0/>.
+The F<perlmulticore.h> header file is put into the public
+domain. Where this is legally not possible, or at your
+option, it can be licensed under creativecommons CC0
+license: L<https://creativecommons.org/publicdomain/zero/1.0/>.
 
 =cut
+
 */
 
+#define PERL_MULTICORE_MAJOR 1 /* bumped on incompatible changes */
+#define PERL_MULTICORE_MINOR 0 /* bumped on every change */
+
+#if PERL_MULTICORE_DISABLE
+
+#define perlinterp_release() do { } while (0)
+#define perlinterp_acquire() do { } while (0)
+
+#else
+
+/* this struct is shared between all modules, and currently */
+/* contain only the two function pointers for release/acquire */
 struct perl_multicore_api
 {
   void (*pmapi_release)(void);
@@ -335,11 +360,14 @@
 #define perlinterp_release() perl_multicore_api->pmapi_release ()
 #define perlinterp_acquire() perl_multicore_api->pmapi_acquire ()
 
+/* this is the release/acquire implementation used as fallback */
 static void
 perl_multicore_nop (void)
 {
 }
 
+/* this is the initial implementation of "release" - it initialises */
+/* the api and then calls the real release function */
 static void
 perl_multicore_init (void)
 {
@@ -367,3 +395,5 @@
 }
 
 #endif
+
+#endif