/*************************************************************************/ /* safe_refcount.cpp */ /*************************************************************************/ /* This file is part of: */ /* GODOT ENGINE */ /* https://godotengine.org */ /*************************************************************************/ /* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur. */ /* Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md) */ /* */ /* Permission is hereby granted, free of charge, to any person obtaining */ /* a copy of this software and associated documentation files (the */ /* "Software"), to deal in the Software without restriction, including */ /* without limitation the rights to use, copy, modify, merge, publish, */ /* distribute, sublicense, and/or sell copies of the Software, and to */ /* permit persons to whom the Software is furnished to do so, subject to */ /* the following conditions: */ /* */ /* The above copyright notice and this permission notice shall be */ /* included in all copies or substantial portions of the Software. */ /* */ /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */ /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */ /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/ /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */ /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */ /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */ /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /*************************************************************************/ #include "safe_refcount.h" // Atomic functions, these are used for multithread safe reference counters! #ifdef NO_THREADS /* Bogus implementation unaware of multiprocessing */ template static _ALWAYS_INLINE_ T _atomic_conditional_increment_impl(register T *pw) { if (*pw == 0) return 0; (*pw)++; return *pw; } template static _ALWAYS_INLINE_ T _atomic_decrement_impl(register T *pw) { (*pw)--; return *pw; } template static _ALWAYS_INLINE_ T _atomic_increment_impl(register T *pw) { (*pw)++; return *pw; } template static _ALWAYS_INLINE_ T _atomic_sub_impl(register T *pw, register T val) { (*pw) -= val; return *pw; } template static _ALWAYS_INLINE_ T _atomic_add_impl(register T *pw, register T val) { (*pw) += val; return *pw; } template 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 */ // GCC guarantees atomic intrinsics for sizes of 1, 2, 4 and 8 bytes. // Clang states it supports GCC atomic builtins. template static _ALWAYS_INLINE_ T _atomic_conditional_increment_impl(register T *pw) { while (true) { T tmp = static_cast(*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 static _ALWAYS_INLINE_ T _atomic_decrement_impl(register T *pw) { return __sync_sub_and_fetch(pw, 1); } template static _ALWAYS_INLINE_ T _atomic_increment_impl(register T *pw) { return __sync_add_and_fetch(pw, 1); } template static _ALWAYS_INLINE_ T _atomic_sub_impl(register T *pw, register T val) { return __sync_sub_and_fetch(pw, val); } template static _ALWAYS_INLINE_ T _atomic_add_impl(register T *pw, register T val) { return __sync_add_and_fetch(pw, val); } template static _ALWAYS_INLINE_ T _atomic_exchange_if_greater_impl(register T *pw, register T val) { while (true) { T tmp = static_cast(*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 #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_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_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) } static _ALWAYS_INLINE_ uint32_t _atomic_decrement_impl(register uint32_t *pw) { return InterlockedDecrement((LONG volatile *)pw); } static _ALWAYS_INLINE_ uint32_t _atomic_increment_impl(register uint32_t *pw) { return InterlockedIncrement((LONG volatile *)pw); } static _ALWAYS_INLINE_ uint32_t _atomic_sub_impl(register uint32_t *pw, register uint32_t val) { return InterlockedExchangeAdd((LONG volatile *)pw, -(int32_t)val) - val; } static _ALWAYS_INLINE_ uint32_t _atomic_add_impl(register uint32_t *pw, register uint32_t val) { 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) } static _ALWAYS_INLINE_ uint64_t _atomic_decrement_impl(register uint64_t *pw) { return InterlockedDecrement64((LONGLONG volatile *)pw); } static _ALWAYS_INLINE_ uint64_t _atomic_increment_impl(register uint64_t *pw) { return InterlockedIncrement64((LONGLONG volatile *)pw); } static _ALWAYS_INLINE_ uint64_t _atomic_sub_impl(register uint64_t *pw, register uint64_t val) { return InterlockedExchangeAdd64((LONGLONG volatile *)pw, -(int64_t)val) - val; } static _ALWAYS_INLINE_ uint64_t _atomic_add_impl(register uint64_t *pw, register uint64_t val) { 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? #error Must provide atomic functions for this platform or compiler! #endif // The actual advertised functions; they'll call the right implementation uint32_t atomic_conditional_increment(register uint32_t *counter) { return _atomic_conditional_increment_impl(counter); } uint32_t atomic_decrement(register uint32_t *pw) { return _atomic_decrement_impl(pw); } uint32_t atomic_increment(register uint32_t *pw) { return _atomic_increment_impl(pw); } uint32_t atomic_sub(register uint32_t *pw, register uint32_t val) { return _atomic_sub_impl(pw, val); } 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); } uint64_t atomic_decrement(register uint64_t *pw) { return _atomic_decrement_impl(pw); } uint64_t atomic_increment(register uint64_t *pw) { return _atomic_increment_impl(pw); } uint64_t atomic_sub(register uint64_t *pw, register uint64_t val) { return _atomic_sub_impl(pw, 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); }