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| author | Hein-Pieter van Braam | 2017-09-25 00:01:55 +0200 |
|---|---|---|
| committer | Hein-Pieter van Braam | 2017-09-25 18:29:18 +0200 |
| commit | 158c3fbf3cf0116cdf5d7b74237db6c56db24e4f (patch) | |
| tree | 4d1a722dab42e2969dec59e32a52ecfa5a94c7b6 /core/safe_refcount.h | |
| parent | 0a338a28d913b882f63444820073fecc421cbd5d (diff) | |
| download | godot-158c3fbf3cf0116cdf5d7b74237db6c56db24e4f.tar.gz godot-158c3fbf3cf0116cdf5d7b74237db6c56db24e4f.tar.zst godot-158c3fbf3cf0116cdf5d7b74237db6c56db24e4f.zip | |
Diffstat (limited to 'core/safe_refcount.h')
| -rw-r--r-- | core/safe_refcount.h | 227 |
1 files changed, 210 insertions, 17 deletions
diff --git a/core/safe_refcount.h b/core/safe_refcount.h index 802d84ccc..05126cc31 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); +// Atomic functions, these are used for multithread safe reference counters! -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); +#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; } |
