[atomic] Add hb_atomic_ptr_t<> and port all uses
Found and fixed a couple bugs.
Found a couple multithreading issues. Marked them with "XXX-MT-bug".
diff --git a/src/hb-shaper-private.hh b/src/hb-shaper-private.hh
index 457cd95..fb04bbc 100644
--- a/src/hb-shaper-private.hh
+++ b/src/hb-shaper-private.hh
@@ -56,7 +56,7 @@
#define HB_SHAPER_DATA_TYPE_NAME(shaper, object) hb_##shaper##_##object##_data_t
#define HB_SHAPER_DATA_TYPE(shaper, object) struct HB_SHAPER_DATA_TYPE_NAME(shaper, object)
-#define HB_SHAPER_DATA_INSTANCE(shaper, object, instance) (* (HB_SHAPER_DATA_TYPE(shaper, object) **) &(instance)->shaper_data.shaper)
+#define HB_SHAPER_DATA_INSTANCE(shaper, object, instance) (* reinterpret_cast<hb_atomic_ptr_t<HB_SHAPER_DATA_TYPE(shaper, object) *> *> (&(instance)->shaper_data.shaper))
#define HB_SHAPER_DATA(shaper, object) HB_SHAPER_DATA_INSTANCE(shaper, object, object)
#define HB_SHAPER_DATA_CREATE_FUNC(shaper, object) _hb_##shaper##_shaper_##object##_data_create
#define HB_SHAPER_DATA_DESTROY_FUNC(shaper, object) _hb_##shaper##_shaper_##object##_data_destroy
@@ -72,7 +72,7 @@
HB_SHAPER_DATA_ENSURE_FUNC (shaper, object) (hb_##object##_t *object)
#define HB_SHAPER_DATA_DESTROY(shaper, object) \
- if (HB_SHAPER_DATA_TYPE (shaper, object) *data = HB_SHAPER_DATA (shaper, object)) \
+ if (HB_SHAPER_DATA_TYPE (shaper, object) *data = HB_SHAPER_DATA (shaper, object).get ()) \
if (data != HB_SHAPER_DATA_INVALID && data != HB_SHAPER_DATA_SUCCEEDED) \
HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (data);
@@ -84,9 +84,10 @@
HB_SHAPER_DATA_ENSURE_FUNC(shaper, object) (hb_##object##_t *object) \
{\
retry: \
- HB_SHAPER_DATA_TYPE (shaper, object) *data = (HB_SHAPER_DATA_TYPE (shaper, object) *) hb_atomic_ptr_get (&HB_SHAPER_DATA (shaper, object)); \
+ HB_SHAPER_DATA_TYPE (shaper, object) *data = HB_SHAPER_DATA (shaper, object).get (); \
if (likely (data) && !(condition)) { \
- /* Note that evaluating condition above can be dangerous if another thread \
+ /* XXX-MT-bug \
+ * Note that evaluating condition above can be dangerous if another thread \
* got here first and destructed data. That's, as always, bad use pattern. \
* If you modify the font (change font size), other threads must not be \
* using it at the same time. However, since this check is delayed to \
@@ -99,7 +100,8 @@
/* Drop and recreate. */ \
/* If someone dropped it in the mean time, throw it away and don't touch it. \
* Otherwise, destruct it. */ \
- if (hb_atomic_ptr_cmpexch (&HB_SHAPER_DATA (shaper, object), data, nullptr)) { \
+ if (likely (HB_SHAPER_DATA (shaper, object).cmpexch (data, nullptr))) \
+ { \
HB_SHAPER_DATA_DESTROY_FUNC (shaper, object) (data); \
} \
goto retry; \
@@ -108,7 +110,7 @@
data = HB_SHAPER_DATA_CREATE_FUNC (shaper, object) (object); \
if (unlikely (!data)) \
data = (HB_SHAPER_DATA_TYPE (shaper, object) *) HB_SHAPER_DATA_INVALID; \
- if (!hb_atomic_ptr_cmpexch (&HB_SHAPER_DATA (shaper, object), nullptr, data)) { \
+ if (unlikely (!HB_SHAPER_DATA (shaper, object).cmpexch (nullptr, data))) { \
if (data && \
data != HB_SHAPER_DATA_INVALID && \
data != HB_SHAPER_DATA_SUCCEEDED) \
@@ -122,7 +124,7 @@
/* For embedding in face / font / ... */
struct hb_shaper_data_t {
-#define HB_SHAPER_IMPLEMENT(shaper) void *shaper;
+#define HB_SHAPER_IMPLEMENT(shaper) hb_atomic_ptr_t<void *> shaper;
#include "hb-shaper-list.hh"
#undef HB_SHAPER_IMPLEMENT
};
