Use pthread_once() instead of marking libkqueue_init() as a constructor.

This gives the correct behavior for both static and dynamic libraries.


git-svn-id: svn://svn.code.sf.net/p/libkqueue/code/trunk@591 fb4e3144-bc1c-4b72-a658-5bcd248dd7f7

BUGS

@@ -1,3 +1,6 @@
+ * On Windows, you need to supply -DMAKE_STATIC in CFLAGS when building the
+   static library. This does not apply when using cmake.
+
  * When passing a knote pointer to the kernel, the reference count of
    the knote structure should be incremented. Conversely, when the pointer
    has been returned from the kernel and the event unregistered from the

src/common/kqueue.c

@@ -27,6 +27,11 @@
 int DEBUG_KQUEUE = 0;
 char *KQUEUE_DEBUG_IDENT = "KQ";
 
+#ifndef _WIN32
+pthread_mutex_t kq_mtx = PTHREAD_MUTEX_INITIALIZER;
+pthread_once_t kq_is_initialized = PTHREAD_ONCE_INIT;
+#endif
+
 static unsigned int
 get_fd_limit(void)
 {
@@ -51,10 +56,7 @@ get_fd_limit(void)
 
 static struct map *kqmap;
 
-int CONSTRUCTOR
-#ifdef MAKE_STATIC
-       VISIBLE
-#endif
+static void
 libkqueue_init(void)
 {
 #ifdef NDEBUG
@@ -80,7 +82,6 @@ libkqueue_init(void)
    if (knote_init() < 0)
        abort();
    dbg_puts("library initialization complete");
-   return (0);
 }
 
 #if DEADWOOD
@@ -114,6 +115,10 @@ kqueue(void)
 	struct kqueue *kq;
     struct kqueue *tmp;
 
+    (void) pthread_mutex_lock(&kq_mtx);
+    (void) pthread_once(&kq_is_initialized, libkqueue_init);
+    (void) pthread_mutex_unlock(&kq_mtx);
+
     kq = calloc(1, sizeof(*kq));
     if (kq == NULL)
         return (-1);

src/common/private.h

@@ -208,6 +208,4 @@ void       *map_lookup(struct map *, int);
 void       *map_delete(struct map *, int);
 void        map_free(struct map *);
 
-int CONSTRUCTOR libkqueue_init(void);
-
 #endif  /* ! _KQUEUE_PRIVATE_H */

src/posix/platform.h

@@ -39,11 +39,6 @@
 /*
  * GCC-compatible attributes
  */
-#ifdef MAKE_STATIC
-# define CONSTRUCTOR
-#else
-# define CONSTRUCTOR     __attribute__ ((constructor))
-#endif
 #define VISIBLE         __attribute__((visibility("default")))
 #define HIDDEN          __attribute__((visibility("hidden")))
 #define UNUSED          __attribute__((unused))

src/windows/platform.c

@@ -58,8 +58,7 @@ BOOL WINAPI DllMain(
             if (WSAStartup(MAKEWORD(2,2), NULL) != 0)
                 return (FALSE);
 #endif
-            if (libkqueue_init() < 0)
-				return (FALSE);
+            libkqueue_init();
             break;
 
         case DLL_PROCESS_DETACH:

src/windows/platform.h

@@ -99,12 +99,6 @@ int     windows_filter_init(struct kqueue *, struct filter *);
 void    windows_filter_free(struct kqueue *, struct filter *);
 int     windows_get_descriptor_type(struct knote *);
 
-/* Windows does not support this attribute.
-   DllMain() is the only available constructor function.
-   This means the constructor must be called from within DllMain().
- */
-#define CONSTRUCTOR
-
 /*
  * GCC-compatible branch prediction macros
  */