Minor refactoring to the atomics implementation

s/atomic_int/atomic_int_impl/ and s/atomic_ptr/atomic_ptr_impl/
to bring it in par with hb_mutex_impl_t, then re-introduce
hb_atomic_int_t as a wrapper around hb_atomic_int_impl_t.

In hb_reference_count_t, make it clear the non-atomic get and set
are intentional due to nature of the cases they are used in
(comparison to -1 and the debug output/tracing).

diff --git a/src/hb-atomic-private.hh b/src/hb-atomic-private.hh
index 6fa86d3..b08e90c 100644 (file)
--- a/src/hb-atomic-private.hh
+++ b/src/hb-atomic-private.hh
@@ -39,11 +39,11 @@
 
 /* We need external help for these */
 
-#if defined(hb_atomic_int_add) \
- && defined(hb_atomic_ptr_get) \
- && defined(hb_atomic_ptr_cmpexch)
+#if defined(hb_atomic_int_impl_add) \
+ && defined(hb_atomic_ptr_impl_get) \
+ && defined(hb_atomic_ptr_impl_cmpexch)
 
-/* Defined externally, i.e. in config.h */
+/* Defined externally, i.e. in config.h; must have typedef'ed hb_atomic_int_impl_t as well. */
 
 
 #elif !defined(HB_NO_MT) && (defined(_WIN32) || defined(__CYGWIN__))
@@ -62,11 +62,11 @@ static inline void _HBMemoryBarrier (void) {
 #endif
 }
 
-typedef LONG hb_atomic_int_t;
-#define hb_atomic_int_add(AI, V)       InterlockedExchangeAdd (&(AI), (V))
+typedef LONG hb_atomic_int_impl_t;
+#define hb_atomic_int_impl_add(AI, V)          InterlockedExchangeAdd (&(AI), (V))
 
-#define hb_atomic_ptr_get(P)           (_HBMemoryBarrier (), (void *) *(P))
-#define hb_atomic_ptr_cmpexch(P,O,N)   (InterlockedCompareExchangePointer ((void **) (P), (void *) (N), (void *) (O)) == (void *) (O))
+#define hb_atomic_ptr_impl_get(P)              (_HBMemoryBarrier (), (void *) *(P))
+#define hb_atomic_ptr_impl_cmpexch(P,O,N)      (InterlockedCompareExchangePointer ((void **) (P), (void *) (N), (void *) (O)) == (void *) (O))
 
 
 #elif !defined(HB_NO_MT) && defined(__APPLE__)
@@ -78,28 +78,31 @@ typedef LONG hb_atomic_int_t;
 #include <Availability.h>
 #endif
 
-typedef int32_t hb_atomic_int_t;
-#define hb_atomic_int_add(AI, V)       (OSAtomicAdd32Barrier ((V), &(AI)) - (V))
 
-#define hb_atomic_ptr_get(P)           (OSMemoryBarrier (), (void *) *(P))
+typedef int32_t hb_atomic_int_impl_t;
+#define HB_ATOMIC_INT_IMPL_INIT(V) (V)
+#define hb_atomic_int_impl_add(AI, V)          (OSAtomicAdd32Barrier ((V), &(AI)) - (V))
+
+#define hb_atomic_ptr_impl_get(P)              (OSMemoryBarrier (), (void *) *(P))
 #if (MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4 || __IPHONE_VERSION_MIN_REQUIRED >= 20100)
-#define hb_atomic_ptr_cmpexch(P,O,N)   OSAtomicCompareAndSwapPtrBarrier ((void *) (O), (void *) (N), (void **) (P))
+#define hb_atomic_ptr_impl_cmpexch(P,O,N)      OSAtomicCompareAndSwapPtrBarrier ((void *) (O), (void *) (N), (void **) (P))
 #else
 #if __ppc64__ || __x86_64__ || __aarch64__
-#define hb_atomic_ptr_cmpexch(P,O,N)    OSAtomicCompareAndSwap64Barrier ((int64_t) (O), (int64_t) (N), (int64_t*) (P))
+#define hb_atomic_ptr_impl_cmpexch(P,O,N)      OSAtomicCompareAndSwap64Barrier ((int64_t) (O), (int64_t) (N), (int64_t*) (P))
 #else
-#define hb_atomic_ptr_cmpexch(P,O,N)    OSAtomicCompareAndSwap32Barrier ((int32_t) (O), (int32_t) (N), (int32_t*) (P))
+#define hb_atomic_ptr_impl_cmpexch(P,O,N)      OSAtomicCompareAndSwap32Barrier ((int32_t) (O), (int32_t) (N), (int32_t*) (P))
 #endif
 #endif
 
 
 #elif !defined(HB_NO_MT) && defined(HAVE_INTEL_ATOMIC_PRIMITIVES)
 
-typedef int hb_atomic_int_t;
-#define hb_atomic_int_add(AI, V)       __sync_fetch_and_add (&(AI), (V))
+typedef int hb_atomic_int_impl_t;
+#define HB_ATOMIC_INT_IMPL_INIT(V) (V)
+#define hb_atomic_int_impl_add(AI, V)          __sync_fetch_and_add (&(AI), (V))
 
-#define hb_atomic_ptr_get(P)           (void *) (__sync_synchronize (), *(P))
-#define hb_atomic_ptr_cmpexch(P,O,N)   __sync_bool_compare_and_swap ((P), (O), (N))
+#define hb_atomic_ptr_impl_get(P)              (void *) (__sync_synchronize (), *(P))
+#define hb_atomic_ptr_impl_cmpexch(P,O,N)      __sync_bool_compare_and_swap ((P), (O), (N))
 
 
 #elif !defined(HB_NO_MT) && defined(HAVE_SOLARIS_ATOMIC_OPS)
@@ -107,33 +110,54 @@ typedef int hb_atomic_int_t;
 #include <atomic.h>
 #include <mbarrier.h>
 
-typedef unsigned int hb_atomic_int_t;
-#define hb_atomic_int_add(AI, V)       ( ({__machine_rw_barrier ();}), atomic_add_int_nv (&(AI), (V)) - (V))
+typedef unsigned int hb_atomic_int_impl_t;
+#define HB_ATOMIC_INT_IMPL_INIT(V) (V)
+#define hb_atomic_int_impl_add(AI, V)          ( ({__machine_rw_barrier ();}), atomic_add_int_nv (&(AI), (V)) - (V))
 
-#define hb_atomic_ptr_get(P)           ( ({__machine_rw_barrier ();}), (void *) *(P))
-#define hb_atomic_ptr_cmpexch(P,O,N)   ( ({__machine_rw_barrier ();}), atomic_cas_ptr ((void **) (P), (void *) (O), (void *) (N)) == (void *) (O) ? true : false)
+#define hb_atomic_ptr_impl_get(P)              ( ({__machine_rw_barrier ();}), (void *) *(P))
+#define hb_atomic_ptr_impl_cmpexch(P,O,N)      ( ({__machine_rw_barrier ();}), atomic_cas_ptr ((void **) (P), (void *) (O), (void *) (N)) == (void *) (O) ? true : false)
 
 
 #elif !defined(HB_NO_MT)
 
 #define HB_ATOMIC_INT_NIL 1 /* Warn that fallback implementation is in use. */
-typedef volatile int hb_atomic_int_t;
-#define hb_atomic_int_add(AI, V)       (((AI) += (V)) - (V))
 
-#define hb_atomic_ptr_get(P)           ((void *) *(P))
-#define hb_atomic_ptr_cmpexch(P,O,N)   (* (void * volatile *) (P) == (void *) (O) ? (* (void * volatile *) (P) = (void *) (N), true) : false)
+typedef volatile int hb_atomic_int_impl_t;
+#define HB_ATOMIC_INT_IMPL_INIT(V) (V)
+#define hb_atomic_int_impl_add(AI, V)          (((AI) += (V)) - (V))
+
+#define hb_atomic_ptr_impl_get(P)              ((void *) *(P))
+#define hb_atomic_ptr_impl_cmpexch(P,O,N)      (* (void * volatile *) (P) == (void *) (O) ? (* (void * volatile *) (P) = (void *) (N), true) : false)
 
 
 #else /* HB_NO_MT */
 
-typedef int hb_atomic_int_t;
-#define hb_atomic_int_add(AI, V)       (((AI) += (V)) - (V))
+typedef int hb_atomic_int_impl_t;
+#define HB_ATOMIC_INT_IMPL_INIT(V)             (V)
+#define hb_atomic_int_impl_add(AI, V)          (((AI) += (V)) - (V))
+
+#define hb_atomic_ptr_impl_get(P)              ((void *) *(P))
+#define hb_atomic_ptr_impl_cmpexch(P,O,N)      (* (void **) (P) == (void *) (O) ? (* (void **) (P) = (void *) (N), true) : false)
 
-#define hb_atomic_ptr_get(P)           ((void *) *(P))
-#define hb_atomic_ptr_cmpexch(P,O,N)   (* (void **) (P) == (void *) (O) ? (* (void **) (P) = (void *) (N), true) : false)
 
 #endif
 
-/* TODO Add tracing. */
+
+#define HB_ATOMIC_INT_INIT(V)          {HB_ATOMIC_INT_IMPL_INIT(V)}
+
+struct hb_atomic_int_t
+{
+  hb_atomic_int_impl_t ref;
+
+  inline void set_unsafe (int v) { ref = v; }
+  inline int get_unsafe (void) const { return ref; }
+  inline int inc (void) { return hb_atomic_int_impl_add (const_cast<hb_atomic_int_impl_t &> (ref),  1); }
+  inline int dec (void) { return hb_atomic_int_impl_add (const_cast<hb_atomic_int_impl_t &> (ref), -1); }
+};
+
+
+#define hb_atomic_ptr_get(P) hb_atomic_ptr_impl_get(P)
+#define hb_atomic_ptr_cmpexch(P,O,N) hb_atomic_ptr_impl_cmpexch((P),(O),(N))
+
 
 #endif /* HB_ATOMIC_PRIVATE_HH */

diff --git a/src/hb-mutex-private.hh b/src/hb-mutex-private.hh
index 89fc8de..ed27035 100644 (file)
--- a/src/hb-mutex-private.hh
+++ b/src/hb-mutex-private.hh
@@ -45,7 +45,7 @@
  && defined(hb_mutex_impl_unlock) \
  && defined(hb_mutex_impl_finish)
 
-/* Defined externally, i.e. in config.h */
+/* Defined externally, i.e. in config.h; must have typedef'ed hb_mutex_impl_t as well. */
 
 
 #elif !defined(HB_NO_MT) && (defined(_WIN32) || defined(__CYGWIN__))
@@ -119,10 +119,12 @@ typedef int hb_mutex_impl_t;
 #define hb_mutex_impl_unlock(M)        HB_STMT_START {} HB_STMT_END
 #define hb_mutex_impl_finish(M)        HB_STMT_START {} HB_STMT_END
 
+
 #endif
 
 
 #define HB_MUTEX_INIT          {HB_MUTEX_IMPL_INIT}
+
 struct hb_mutex_t
 {
   /* TODO Add tracing. */

diff --git a/src/hb-object-private.hh b/src/hb-object-private.hh
index 7bd0f16..635d62d 100644 (file)
--- a/src/hb-object-private.hh
+++ b/src/hb-object-private.hh
@@ -47,19 +47,20 @@
 
 /* reference_count */
 
-#define HB_REFERENCE_COUNT_INVALID_VALUE ((hb_atomic_int_t) -1)
-#define HB_REFERENCE_COUNT_INVALID {HB_REFERENCE_COUNT_INVALID_VALUE}
+#define HB_REFERENCE_COUNT_INVALID_VALUE -1
+#define HB_REFERENCE_COUNT_INIT {HB_ATOMIC_INT_INIT(HB_REFERENCE_COUNT_INVALID_VALUE)}
+
 struct hb_reference_count_t
 {
   hb_atomic_int_t ref_count;
 
-  inline void init (int v) { ref_count = v; }
-  inline int inc (void) { return hb_atomic_int_add (const_cast<hb_atomic_int_t &> (ref_count),  1); }
-  inline int dec (void) { return hb_atomic_int_add (const_cast<hb_atomic_int_t &> (ref_count), -1); }
-  inline void finish (void) { ref_count = HB_REFERENCE_COUNT_INVALID_VALUE; }
-
-  inline bool is_invalid (void) const { return ref_count == HB_REFERENCE_COUNT_INVALID_VALUE; }
+  inline void init (int v) { ref_count.set_unsafe (v); }
+  inline int get_unsafe (void) const { return ref_count.get_unsafe (); }
+  inline int inc (void) { return ref_count.inc (); }
+  inline int dec (void) { return ref_count.dec (); }
+  inline void finish (void) { ref_count.set_unsafe (HB_REFERENCE_COUNT_INVALID_VALUE); }
 
+  inline bool is_invalid (void) const { return ref_count.get_unsafe () == HB_REFERENCE_COUNT_INVALID_VALUE; }
 };
 
 
@@ -102,7 +103,7 @@ struct hb_object_header_t
   hb_reference_count_t ref_count;
   hb_user_data_array_t user_data;
 
-#define HB_OBJECT_HEADER_STATIC {HB_REFERENCE_COUNT_INVALID, HB_USER_DATA_ARRAY_INIT}
+#define HB_OBJECT_HEADER_STATIC {HB_REFERENCE_COUNT_INIT, HB_USER_DATA_ARRAY_INIT}
 
   private:
   ASSERT_POD ();
@@ -117,7 +118,7 @@ static inline void hb_object_trace (const Type *obj, const char *function)
   DEBUG_MSG (OBJECT, (void *) obj,
             "%s refcount=%d",
             function,
-            obj ? obj->header.ref_count.ref_count : 0);
+            obj ? obj->header.ref_count.get_unsafe () : 0);
 }
 
 template <typename Type>