thread-safe fftw on windows too

Signed-off-by: falkTX <falktx@falktx.com>

.travis.yml

@@ -13,7 +13,7 @@ cache:
 
 env:
   global:
-    - BOOTSTRAP_VERSION=11
+    - BOOTSTRAP_VERSION=12
 
 jobs:
   include:

patches/fftw/01_static-planner-thread-safe.patch

@@ -1,12 +1,40 @@
---- fftw3-static-3.3.5~git20160520.orig/api/apiplan.c
-+++ fftw3-static-3.3.5~git20160520/api/apiplan.c
-@@ -19,8 +19,21 @@
-  */
+diff --git a/api/apiplan.c b/api/apiplan.c
+index b8642a9..d63f2e4 100644
+--- a/api/apiplan.c
++++ b/api/apiplan.c
+@@ -20,7 +20,48 @@
  
  #include "api/api.h"
-+#include <pthread.h>
  
 -static planner_hook_t before_planner_hook = 0, after_planner_hook = 0;
++#if defined(__WIN32__) || defined(_WIN32) || defined(_WINDOWS)
++/* hack: windef.h defines INT for its own purposes and this causes
++   a conflict with our own INT in ifftw.h.  Divert the windows
++   definition into another name unlikely to cause a conflict */
++#define INT magnus_ab_INTegro_seclorum_nascitur_ordo
++#include <windows.h>
++#undef INT
++
++/* windows does not have statically-initialized mutexes---fake a
++   spinlock */
++static volatile LONG planner_mutex = 0;
++
++static void lock_planner_mutex(void)
++{
++     while (InterlockedExchange(&planner_mutex, 1) == 1) {
++          YieldProcessor();
++          Sleep(0);
++     }
++}
++
++static void unlock_planner_mutex(void)
++{
++     LONG old = InterlockedExchange(&planner_mutex, 0);
++     A(old == 1);
++}
++#else
++#include <pthread.h>
++
 +static pthread_mutex_t planner_mutex = PTHREAD_MUTEX_INITIALIZER;
 +
 +static void lock_planner_mutex(void)
@@ -18,6 +46,7 @@
 +{
 +     pthread_mutex_unlock(&planner_mutex);
 +}
++#endif
 +
 +static planner_hook_t before_planner_hook = lock_planner_mutex, after_planner_hook = unlock_planner_mutex;