Extend add/subtract operations to atomics

Going to be used for counters

2 files changed, 48 insertions, 1 deletions

diff --git a/osi/include/atomic.h b/osi/include/atomic.h
index 171a5393f..beac2f151 100644
--- a/osi/include/atomic.h
+++ b/osi/include/atomic.h
@@ -86,6 +86,18 @@ inline type atomic_dec_postfix_##name(volatile atomic_##name##_t *atomic) { \
   return __atomic_fetch_sub_##sz(atomic, 1, __ATOMIC_SEQ_CST); \
 }
 
+// Returns value after operation, e.g. new value
+#define ATOMIC_ADD(name, type, sz) \
+inline type atomic_add_##name(volatile atomic_##name##_t *atomic, type val) { \
+  return __atomic_add_fetch_##sz(atomic, val, __ATOMIC_SEQ_CST); \
+}
+
+// Returns value after operation, e.g. new value
+#define ATOMIC_SUB(name, type, sz) \
+inline type atomic_sub_##name(volatile atomic_##name##_t *atomic, type val) { \
+  return __atomic_sub_fetch_##sz(atomic, val, __ATOMIC_SEQ_CST); \
+}
+
 #define ATOMIC_MAKE(name, type, sz) \
   ATOMIC_TYPE(name, type) \
   ATOMIC_STORE(name, type, sz) \
@@ -93,7 +105,9 @@ inline type atomic_dec_postfix_##name(volatile atomic_##name##_t *atomic) { \
   ATOMIC_INC_PREFIX(name, type, sz) \
   ATOMIC_DEC_PREFIX(name, type, sz) \
   ATOMIC_INC_POSTFIX(name, type, sz) \
-  ATOMIC_DEC_POSTFIX(name, type, sz)
+  ATOMIC_DEC_POSTFIX(name, type, sz) \
+  ATOMIC_ADD(name, type, sz) \
+  ATOMIC_SUB(name, type, sz)
 
 ATOMIC_MAKE(s32, int32_t, 4)
 ATOMIC_MAKE(u32, uint32_t, 4)
diff --git a/osi/test/atomic_test.cpp b/osi/test/atomic_test.cpp
index bed4733e0..b0039ab3f 100644
--- a/osi/test/atomic_test.cpp
+++ b/osi/test/atomic_test.cpp
@@ -243,3 +243,36 @@ TEST(AtomicTest, test_inc_dec_s64) {
   EXPECT_EQ(-1, val);
   EXPECT_EQ(-2, atomic_load_s64(&data));
 }
+
+TEST(AtomicTest, test_add_sub_u64) {
+  atomic_u64_t data;
+
+  atomic_store_u64(&data, 0);
+  EXPECT_EQ((unsigned)0, atomic_load_u64(&data));
+
+  uint64_t val = atomic_add_u64(&data, 0xffff);
+  EXPECT_EQ((unsigned)0xffff, atomic_load_u64(&data));
+  EXPECT_EQ((unsigned)0xffff, val);
+
+  val = atomic_add_u64(&data, 0xffff);
+  EXPECT_EQ((unsigned)(2 * 0xffff), atomic_load_u64(&data));
+  EXPECT_EQ((unsigned)(2 * 0xffff), val);
+
+  val = atomic_add_u64(&data, 0xffff);
+  EXPECT_EQ((unsigned)(3 * 0xffff), atomic_load_u64(&data));
+  EXPECT_EQ((unsigned)(3 * 0xffff), val);
+  EXPECT_NE((unsigned)(3 * 0xfff0), val);
+
+  val = atomic_sub_u64(&data, 0xffff);
+  EXPECT_EQ((unsigned)(2 * 0xffff), val);
+
+  val = atomic_sub_u64(&data, 0);
+  EXPECT_EQ((unsigned)(2 * 0xffff), val);
+  val = atomic_sub_u64(&data, 0xffff);
+  EXPECT_EQ((unsigned)(1 * 0xffff), val);
+
+  val = atomic_sub_u64(&data, 0xffff);
+  EXPECT_EQ((unsigned)0, val);
+}
+
+