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-rw-r--r--core/safe_refcount.h229
1 files changed, 211 insertions, 18 deletions
diff --git a/core/safe_refcount.h b/core/safe_refcount.h
index 802d84cccc..05126cc319 100644
--- a/core/safe_refcount.h
+++ b/core/safe_refcount.h
@@ -36,19 +36,212 @@
#include "platform_config.h"
#include "typedefs.h"
-uint32_t atomic_conditional_increment(register uint32_t *counter);
-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);
+// Atomic functions, these are used for multithread safe reference counters!
+
+#ifdef NO_THREADS
+
+/* Bogus implementation unaware of multiprocessing */
+
+template <class T>
+static _ALWAYS_INLINE_ T atomic_conditional_increment(register T *pw) {
+
+ if (*pw == 0)
+ return 0;
+
+ (*pw)++;
+
+ return *pw;
+}
+
+template <class T>
+static _ALWAYS_INLINE_ T atomic_decrement(register T *pw) {
+
+ (*pw)--;
+
+ return *pw;
+}
+
+template <class T>
+static _ALWAYS_INLINE_ T atomic_increment(register T *pw) {
+
+ (*pw)++;
+
+ return *pw;
+}
+
+template <class T, class V>
+static _ALWAYS_INLINE_ T atomic_sub(register T *pw, register V val) {
+
+ (*pw) -= val;
+
+ return *pw;
+}
+
+template <class T, class V>
+static _ALWAYS_INLINE_ T atomic_add(register T *pw, register V val) {
+
+ (*pw) += val;
+
+ return *pw;
+}
+
+template <class T, class V>
+static _ALWAYS_INLINE_ T atomic_exchange_if_greater(register T *pw, register V val) {
+
+ if (val > *pw)
+ *pw = val;
+
+ return *pw;
+}
+
+#elif defined(__GNUC__)
+
+/* Implementation for GCC & Clang */
+
+// GCC guarantees atomic intrinsics for sizes of 1, 2, 4 and 8 bytes.
+// Clang states it supports GCC atomic builtins.
+
+template <class T>
+static _ALWAYS_INLINE_ T atomic_conditional_increment(register T *pw) {
+
+ while (true) {
+ T tmp = static_cast<T const volatile &>(*pw);
+ if (tmp == 0)
+ return 0; // if zero, can't add to it anymore
+ if (__sync_val_compare_and_swap(pw, tmp, tmp + 1) == tmp)
+ return tmp + 1;
+ }
+}
+
+template <class T>
+static _ALWAYS_INLINE_ T atomic_decrement(register T *pw) {
+
+ return __sync_sub_and_fetch(pw, 1);
+}
+
+template <class T>
+static _ALWAYS_INLINE_ T atomic_increment(register T *pw) {
+
+ return __sync_add_and_fetch(pw, 1);
+}
+
+template <class T, class V>
+static _ALWAYS_INLINE_ T atomic_sub(register T *pw, register V val) {
+
+ return __sync_sub_and_fetch(pw, val);
+}
+
+template <class T, class V>
+static _ALWAYS_INLINE_ T atomic_add(register T *pw, register V val) {
+
+ return __sync_add_and_fetch(pw, val);
+}
+
+template <class T, class V>
+static _ALWAYS_INLINE_ T atomic_exchange_if_greater(register T *pw, register V 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 */
+
+// don't pollute my namespace!
+#include <windows.h>
+
+#define ATOMIC_CONDITIONAL_INCREMENT_BODY(m_pw, m_win_type, m_win_cmpxchg, m_cpp_type) \
+ /* try to increment until it actually works */ \
+ /* taken from boost */ \
+ while (true) { \
+ m_cpp_type tmp = static_cast<m_cpp_type const volatile &>(*(m_pw)); \
+ if (tmp == 0) \
+ return 0; /* if zero, can't add to it anymore */ \
+ if (m_win_cmpxchg((m_win_type volatile *)(m_pw), tmp + 1, tmp) == tmp) \
+ 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(register uint32_t *pw) {
+
+ ATOMIC_CONDITIONAL_INCREMENT_BODY(pw, LONG, InterlockedCompareExchange, uint32_t)
+}
+
+static _ALWAYS_INLINE_ uint32_t atomic_decrement(register uint32_t *pw) {
+
+ return InterlockedDecrement((LONG volatile *)pw);
+}
+
+static _ALWAYS_INLINE_ uint32_t atomic_increment(register uint32_t *pw) {
+
+ return InterlockedIncrement((LONG volatile *)pw);
+}
+
+static _ALWAYS_INLINE_ uint32_t atomic_sub(register uint32_t *pw, register uint32_t val) {
+
+ return InterlockedExchangeAdd((LONG volatile *)pw, -(int32_t)val) - val;
+}
+
+static _ALWAYS_INLINE_ uint32_t atomic_add(register uint32_t *pw, register uint32_t val) {
+
+ return InterlockedAdd((LONG volatile *)pw, val);
+}
+
+static _ALWAYS_INLINE_ uint32_t atomic_exchange_if_greater(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(register uint64_t *pw) {
+
+ ATOMIC_CONDITIONAL_INCREMENT_BODY(pw, LONGLONG, InterlockedCompareExchange64, uint64_t)
+}
+
+static _ALWAYS_INLINE_ uint64_t atomic_decrement(register uint64_t *pw) {
+
+ return InterlockedDecrement64((LONGLONG volatile *)pw);
+}
+
+static _ALWAYS_INLINE_ uint64_t atomic_increment(register uint64_t *pw) {
+
+ return InterlockedIncrement64((LONGLONG volatile *)pw);
+}
+
+static _ALWAYS_INLINE_ uint64_t atomic_sub(register uint64_t *pw, register uint64_t val) {
+
+ return InterlockedExchangeAdd64((LONGLONG volatile *)pw, -(int64_t)val) - val;
+}
+
+static _ALWAYS_INLINE_ uint64_t atomic_add(register uint64_t *pw, register uint64_t val) {
+
+ return InterlockedAdd64((LONGLONG volatile *)pw, val);
+}
+
+static _ALWAYS_INLINE_ uint64_t atomic_exchange_if_greater(register uint64_t *pw, register uint64_t val) {
+
+ ATOMIC_EXCHANGE_IF_GREATER_BODY(pw, val, LONGLONG, InterlockedCompareExchange64, uint64_t)
+}
+
+#else
+
+//no threads supported?
+#error Must provide atomic functions for this platform or compiler!
+
+#endif
struct SafeRefCount {
@@ -57,17 +250,17 @@ struct SafeRefCount {
public:
// destroy() is called when weak_count_ drops to zero.
- bool ref() { //true on success
+ _ALWAYS_INLINE_ bool ref() { //true on success
return atomic_conditional_increment(&count) != 0;
}
- uint32_t refval() { //true on success
+ _ALWAYS_INLINE_ uint32_t refval() { //true on success
return atomic_conditional_increment(&count);
}
- bool unref() { // true if must be disposed of
+ _ALWAYS_INLINE_ bool unref() { // true if must be disposed of
if (atomic_decrement(&count) == 0) {
return true;
@@ -76,12 +269,12 @@ public:
return false;
}
- uint32_t get() const { // nothrow
+ _ALWAYS_INLINE_ uint32_t get() const { // nothrow
return count;
}
- void init(uint32_t p_value = 1) {
+ _ALWAYS_INLINE_ void init(uint32_t p_value = 1) {
count = p_value;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-12 20:02:05 +0000