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authorRĂ©mi Verschelde <rverschelde@gmail.com>2017-07-31 23:30:07 +0200
committerGitHub <noreply@github.com>2017-07-31 23:30:07 +0200
commit597ffa03b3399240e806ee524dd3f9725eefb7ab (patch)
treee66ccfddea22e7cdc0edbaa7f9fdaf1d83117dfa
parent878f34d1e1a18398e7e12c778785aee7a1de3367 (diff)
parent27637b9e7f6f7dc59768623225a687f2d595692f (diff)
Merge pull request #9826 from RandomShaper/improve-atomics
Improve/add atomics
-rw-r--r--core/safe_refcount.cpp56
-rw-r--r--core/safe_refcount.h2
2 files changed, 50 insertions, 8 deletions
diff --git a/core/safe_refcount.cpp b/core/safe_refcount.cpp
index d7e5297321..971e9ad1d5 100644
--- a/core/safe_refcount.cpp
+++ b/core/safe_refcount.cpp
@@ -78,6 +78,15 @@ static _ALWAYS_INLINE_ T _atomic_add_impl(register T *pw, register T val) {
return *pw;
}
+template <class T>
+static _ALWAYS_INLINE_ T _atomic_exchange_if_greater_impl(register T *pw, register T val) {
+
+ if (val > *pw)
+ *pw = val;
+
+ return *pw;
+}
+
#elif defined(__GNUC__)
/* Implementation for GCC & Clang */
@@ -121,6 +130,18 @@ static _ALWAYS_INLINE_ T _atomic_add_impl(register T *pw, register T val) {
return __sync_add_and_fetch(pw, val);
}
+template <class T>
+static _ALWAYS_INLINE_ T _atomic_exchange_if_greater_impl(register T *pw, register T val) {
+
+ while (true) {
+ T tmp = static_cast<T const volatile &>(*pw);
+ if (tmp >= val)
+ return tmp; // already greater, or equal
+ if (__sync_val_compare_and_swap(pw, tmp, val) == tmp)
+ return val;
+ }
+}
+
#elif defined(_MSC_VER)
/* Implementation for MSVC-Windows */
@@ -139,6 +160,15 @@ static _ALWAYS_INLINE_ T _atomic_add_impl(register T *pw, register T val) {
return tmp + 1; \
}
+#define ATOMIC_EXCHANGE_IF_GREATER_BODY(m_pw, m_val, m_win_type, m_win_cmpxchg, m_cpp_type) \
+ while (true) { \
+ m_cpp_type tmp = static_cast<m_cpp_type const volatile &>(*(m_pw)); \
+ if (tmp >= m_val) \
+ return tmp; /* already greater, or equal */ \
+ if (m_win_cmpxchg((m_win_type volatile *)(m_pw), m_val, tmp) == tmp) \
+ return m_val; \
+ }
+
static _ALWAYS_INLINE_ uint32_t _atomic_conditional_increment_impl(register uint32_t *pw) {
ATOMIC_CONDITIONAL_INCREMENT_BODY(pw, LONG, InterlockedCompareExchange, uint32_t)
@@ -156,11 +186,7 @@ static _ALWAYS_INLINE_ uint32_t _atomic_increment_impl(register uint32_t *pw) {
static _ALWAYS_INLINE_ uint32_t _atomic_sub_impl(register uint32_t *pw, register uint32_t val) {
-#if _WIN32_WINNT >= 0x0601 // Windows 7+
- return InterlockedExchangeSubtract(pw, val) - val;
-#else
return InterlockedExchangeAdd((LONG volatile *)pw, -(int32_t)val) - val;
-#endif
}
static _ALWAYS_INLINE_ uint32_t _atomic_add_impl(register uint32_t *pw, register uint32_t val) {
@@ -168,6 +194,11 @@ static _ALWAYS_INLINE_ uint32_t _atomic_add_impl(register uint32_t *pw, register
return InterlockedAdd((LONG volatile *)pw, val);
}
+static _ALWAYS_INLINE_ uint32_t _atomic_exchange_if_greater_impl(register uint32_t *pw, register uint32_t val) {
+
+ ATOMIC_EXCHANGE_IF_GREATER_BODY(pw, val, LONG, InterlockedCompareExchange, uint32_t)
+}
+
static _ALWAYS_INLINE_ uint64_t _atomic_conditional_increment_impl(register uint64_t *pw) {
ATOMIC_CONDITIONAL_INCREMENT_BODY(pw, LONGLONG, InterlockedCompareExchange64, uint64_t)
@@ -185,11 +216,7 @@ static _ALWAYS_INLINE_ uint64_t _atomic_increment_impl(register uint64_t *pw) {
static _ALWAYS_INLINE_ uint64_t _atomic_sub_impl(register uint64_t *pw, register uint64_t val) {
-#if _WIN32_WINNT >= 0x0601 && !defined(UWP_ENABLED) // Windows 7+ except UWP
- return InterlockedExchangeSubtract64(pw, val) - val;
-#else
return InterlockedExchangeAdd64((LONGLONG volatile *)pw, -(int64_t)val) - val;
-#endif
}
static _ALWAYS_INLINE_ uint64_t _atomic_add_impl(register uint64_t *pw, register uint64_t val) {
@@ -197,6 +224,11 @@ static _ALWAYS_INLINE_ uint64_t _atomic_add_impl(register uint64_t *pw, register
return InterlockedAdd64((LONGLONG volatile *)pw, val);
}
+static _ALWAYS_INLINE_ uint64_t _atomic_exchange_if_greater_impl(register uint64_t *pw, register uint64_t val) {
+
+ ATOMIC_EXCHANGE_IF_GREATER_BODY(pw, val, LONGLONG, InterlockedCompareExchange64, uint64_t)
+}
+
#else
//no threads supported?
@@ -226,6 +258,10 @@ uint32_t atomic_add(register uint32_t *pw, register uint32_t val) {
return _atomic_add_impl(pw, val);
}
+uint32_t atomic_exchange_if_greater(register uint32_t *pw, register uint32_t val) {
+ return _atomic_exchange_if_greater_impl(pw, val);
+}
+
uint64_t atomic_conditional_increment(register uint64_t *counter) {
return _atomic_conditional_increment_impl(counter);
}
@@ -245,3 +281,7 @@ uint64_t atomic_sub(register uint64_t *pw, register uint64_t val) {
uint64_t atomic_add(register uint64_t *pw, register uint64_t val) {
return _atomic_add_impl(pw, val);
}
+
+uint64_t atomic_exchange_if_greater(register uint64_t *pw, register uint64_t val) {
+ return _atomic_exchange_if_greater_impl(pw, val);
+}
diff --git a/core/safe_refcount.h b/core/safe_refcount.h
index a2d2b5e127..ed0620c777 100644
--- a/core/safe_refcount.h
+++ b/core/safe_refcount.h
@@ -41,12 +41,14 @@ uint32_t atomic_decrement(register uint32_t *pw);
uint32_t atomic_increment(register uint32_t *pw);
uint32_t atomic_sub(register uint32_t *pw, register uint32_t val);
uint32_t atomic_add(register uint32_t *pw, register uint32_t val);
+uint32_t atomic_exchange_if_greater(register uint32_t *pw, register uint32_t val);
uint64_t atomic_conditional_increment(register uint64_t *counter);
uint64_t atomic_decrement(register uint64_t *pw);
uint64_t atomic_increment(register uint64_t *pw);
uint64_t atomic_sub(register uint64_t *pw, register uint64_t val);
uint64_t atomic_add(register uint64_t *pw, register uint64_t val);
+uint64_t atomic_exchange_if_greater(register uint64_t *pw, register uint64_t val);
struct SafeRefCount {