[cairo-mutex] Rewrite defaults for CAIRO_MUTEX macros not defined by the implementation

to make them better match the design I have in mind, that I will
document in a minute.  They are a lot more readable and understandable
now.

1 files changed, 67 insertions, 26 deletions

diff --git a/src/cairo-mutex-private.h b/src/cairo-mutex-private.h
index ed89ef51b..88e88bb0f 100644
--- a/src/cairo-mutex-private.h
+++ b/src/cairo-mutex-private.h
@@ -62,50 +62,91 @@
 
 CAIRO_BEGIN_DECLS
 
+
 #define CAIRO_MUTEX_DECLARE(mutex) extern cairo_mutex_t mutex
 #include "cairo-mutex-list-private.h"
 #undef CAIRO_MUTEX_DECLARE
 
 
-#ifndef CAIRO_MUTEX_INIT
+/* make sure implementations don't fool us: we decide these ourself */
+#undef _CAIRO_MUTEX_USE_STATIC_INITIALIZER
+#undef _CAIRO_MUTEX_USE_STATIC_FINALIZER
+
+
+#ifdef CAIRO_MUTEX_INIT
+
+/* If CAIRO_MUTEX_INIT is defined, we may need to initialize all
+ * static mutex'es. */
+# ifndef CAIRO_MUTEX_INITIALIZE
+#  define CAIRO_MUTEX_INITIALIZE() do {	\
+       if (!_cairo_mutex_initialized)	\
+           _cairo_mutex_initialize ();	\
+   } while(0)
+
+   cairo_private void _cairo_mutex_initialize (void);
+
+   /* and make sure we implement the above */
+#  define _CAIRO_MUTEX_USE_STATIC_INITIALIZER 1
+# endif /* CAIRO_MUTEX_INITIALIZE */
+
+#else /* no CAIRO_MUTEX_INIT */
+
+/* Otherwise we probably don't need to initialize static mutex'es, */
+# ifndef CAIRO_MUTEX_INITIALIZE
+#  define CAIRO_MUTEX_INITIALIZE() CAIRO_MUTEX_NOOP
+# endif /* CAIRO_MUTEX_INITIALIZE */
+
+/* and dynamic ones can be initialized using the static initializer. */
 # define CAIRO_MUTEX_INIT(mutex) do {				\
-    cairo_mutex_t _tmp_mutex = CAIRO_MUTEX_NIL_INITIALIZER;     \
-    memcpy (&(mutex), &_tmp_mutex, sizeof (_tmp_mutex));        \
-} while (0)
-#endif
+      cairo_mutex_t _tmp_mutex = CAIRO_MUTEX_NIL_INITIALIZER;	\
+      memcpy (&(mutex), &_tmp_mutex, sizeof (_tmp_mutex));	\
+  } while (0)
 
-#ifndef CAIRO_MUTEX_FINI
-# define CAIRO_MUTEX_FINI(mutex)	CAIRO_MUTEX_NOOP1(mutex)
-#endif
+#endif /* CAIRO_MUTEX_INIT */
 
 
-#ifndef CAIRO_MUTEX_INITIALIZE
-# define CAIRO_MUTEX_USE_GENERIC_INITIALIZATION 1
-#else
-# undef CAIRO_MUTEX_USE_GENERIC_INITIALIZATION
+#ifdef CAIRO_MUTEX_FINI
+
+/* If CAIRO_MUTEX_FINI is defined, we may need to finalize all
+ * static mutex'es. */
+# ifndef CAIRO_MUTEX_FINALIZE
+#  define CAIRO_MUTEX_FINALIZE() do {	\
+       if (_cairo_mutex_initialized)	\
+           _cairo_mutex_finalize ();	\
+   } while(0)
+
+   cairo_private void _cairo_mutex_finalize (void);
+
+   /* and make sure we implement the above */
+#  define _CAIRO_MUTEX_USE_STATIC_FINALIZER 1
+# endif /* CAIRO_MUTEX_FINALIZE */
+
+#else /* no CAIRO_MUTEX_FINI */
+
+/* Otherwise we probably don't need to finalize static mutex'es, */
 # ifndef CAIRO_MUTEX_FINALIZE
 #  define CAIRO_MUTEX_FINALIZE() CAIRO_MUTEX_NOOP
-# endif
-#endif
+# endif /* CAIRO_MUTEX_FINALIZE */
 
-#if CAIRO_MUTEX_USE_GENERIC_INITIALIZATION
+/* neither do the dynamic ones. */
+# define CAIRO_MUTEX_FINI(mutex)	CAIRO_MUTEX_NOOP1(mutex)
 
-#define CAIRO_MUTEX_INITIALIZE() do { \
-    if (!_cairo_mutex_initialized) \
-        _cairo_mutex_initialize (); \
-} while(0)
+#endif /* CAIRO_MUTEX_FINI */
 
-#define CAIRO_MUTEX_FINALIZE() do { \
-    if (_cairo_mutex_initialized) \
-        _cairo_mutex_finalize (); \
-} while(0)
 
-cairo_private extern cairo_bool_t _cairo_mutex_initialized;
-cairo_private void _cairo_mutex_initialize(void);
-cairo_private void _cairo_mutex_finalize(void);
+#ifndef _CAIRO_MUTEX_USE_STATIC_INITIALIZER
+#define _CAIRO_MUTEX_USE_STATIC_INITIALIZER 0
+#endif
+#ifndef _CAIRO_MUTEX_USE_STATIC_FINALIZER
+#define _CAIRO_MUTEX_USE_STATIC_FINALIZER 0
+#endif
 
+/* only if using static initializer and/or finalizer define the boolean */
+#if _CAIRO_MUTEX_USE_STATIC_INITIALIZER || _CAIRO_MUTEX_USE_STATIC_FINALIZER
+  cairo_private extern cairo_bool_t _cairo_mutex_initialized;
 #endif
 
+
 CAIRO_END_DECLS
 
 /* Make sure everything we want is defined */