Revert "[Tizen] Add codes for Dali Windows Backend"

[platform/core/uifw/dali-core.git] / dali / public-api / object / ref-object.cpp

diff --git a/dali/public-api/object/ref-object.cpp b/dali/public-api/object/ref-object.cpp
index b6961f3..3060f4b 100644 (file)
--- a/dali/public-api/object/ref-object.cpp
+++ b/dali/public-api/object/ref-object.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,9 @@
 // INTERNAL INCLUDES
 #include <dali/public-api/common/dali-common.h>
 
+// EXTERNAL INCLUDES
+#include <stdint.h>
+
 namespace Dali
 {
 
@@ -36,7 +39,12 @@ RefObject::RefObject(const RefObject&)
 
 RefObject::~RefObject()
 {
-  DALI_ASSERT_DEBUG(mCount == 0);
+#ifdef ENABLE_DEBUG
+  if(mCount)
+  {
+    DALI_LOG_ERROR("mCount should be zero, deleting referenced object!\n");
+  }
+#endif // ENABLE_DEBUG
 }
 
 RefObject& RefObject::operator=(const RefObject&)
@@ -47,14 +55,107 @@ RefObject& RefObject::operator=(const RefObject&)
 
 void RefObject::Reference()
 {
-  // gcc > 4.1 builtin atomic add and fetch (++mCount; return mCount)
-  __sync_add_and_fetch(&mCount, 1);
+  // The inline assembly below was tested on an ARMv8 64 bit platform on
+  // 2015-02-06 and found to run in 11.8 nanoseconds, whereas
+  // __sync_add_and_fetch( address, 1 ) required 18.8 nanoseconds.
+  // Including the assembly here produced one fewer assembly instruction than if
+  // it was wrapped in a function and inlined here by the compiler.
+#if defined __aarch64__
+
+  asm volatile(
+  "1:\tldxr  w1, %[address] \n\t"
+      "add   w1, w1, %[one] \n\t"
+      "stxr  w2,  w1, %[address] \n\t"
+      "cbnz  w2,  1b \n\t"
+      // Outputs:
+    : // Q = A memory address with no offset
+      // ( https://gcc.gnu.org/onlinedocs/gcc/Machine-Constraints.html#Machine-Constraints )
+      [address] "+Q" (mCount)
+      // Inputs:
+    : [one] "Ir" (1)
+      // Clobbers: (explicitly clobber w1 register to hold the loaded value and
+      // register w2 to hold success/fail):
+    : "w1", "w2"
+  );
+
+  // 32 bit ARMv7 version of above:
+  // Better than the code emitted by GCC for __sync_add_and_fetch(), as that
+  // includes two dmb memory barrier instructions: one before and one after the
+  // loop.
+#elif defined __arm__
+
+  asm volatile(
+    "1:\tldrex r1, %[address] \n\t"
+        "add   r1, r1, %[one] \n\t"
+        "strex r2,  r1, %[address] \n\t"
+        "teq   r2,  %[zero] \n\t"
+        "bne   1b \n\t"
+        // Outputs:
+      : [address] "+Q" (mCount)
+        // Inputs:
+      : [zero] "Ir" (0),
+        [one]  "Ir" (1)
+        // Clobbers: (modified registers):
+      : "r1", "r2"
+    );
+
+#else
+
+  // gcc > 4.1 builtin atomic add and fetch:
+  __sync_add_and_fetch( &mCount, 1 );
+
+#endif
 }
 
 void RefObject::Unreference()
 {
+  // The output register:
+  int32_t newValue;
+
+#if defined __aarch64__
+
+  asm volatile(
+  "1:\tldxr   %w[newValue], %[address] \n\t"
+      "sub   %w[newValue], %w[newValue], %[one] \n\t"
+      "stxr  w2,  %w[newValue], %[address] \n\t"
+      "cbnz  w2,  1b \n\t"
+    // Outputs:
+  : [newValue] "=&r" (newValue),
+    // Q = A memory address with no offset
+    // ( https://gcc.gnu.org/onlinedocs/gcc/Machine-Constraints.html#Machine-Constraints )
+    [address] "+Q" (mCount)
+    // Inputs:
+  : [one]  "Ir" (1)
+    // Clobbered: I.e., stuff that is modified.
+  : "w2"
+  );
+
+#elif defined __arm__
+
+  asm volatile(
+  "1:\tldrex %[newValue], %[address] \n\t"
+      "sub   %[newValue], %[newValue], %[one] \n\t"
+      "strex r2,  %[newValue], %[address] \n\t"
+      "teq   r2, %[zero] \n\t"
+      "bne   1b \n\t"
+    // Outputs:
+  : [newValue] "=&r" (newValue),
+    [address] "+Q" (mCount)
+    // Inputs:
+    : [zero] "Ir" (0),
+      [one]  "Ir" (1)
+    // Clobbered:
+  : "r2"
+  );
+
+#else
+
   // gcc > 4.1 builtin atomic subtract and fetch (--mCount; return mCount)
-  if (__sync_sub_and_fetch(&mCount, 1) == 0)
+  newValue = __sync_sub_and_fetch( &mCount, 1 );
+
+#endif
+
+  if( newValue == 0 )
   {
     delete this;
   }