/*************************************************************************/
/* safe_refcount.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2017 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 <class T>
static _ALWAYS_INLINE_ T _atomic_conditional_increment_impl(register T *pw) {
if (*pw == 0)
return 0;
(*pw)++;
return *pw;
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_decrement_impl(register T *pw) {
(*pw)--;
return *pw;
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_increment_impl(register T *pw) {
(*pw)++;
return *pw;
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_sub_impl(register T *pw, register T val) {
(*pw) -= val;
return *pw;
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_add_impl(register T *pw, register T val) {
(*pw) += 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 */
// 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_impl(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_impl(register T *pw) {
return __sync_sub_and_fetch(pw, 1);
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_increment_impl(register T *pw) {
return __sync_add_and_fetch(pw, 1);
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_sub_impl(register T *pw, register T val) {
return __sync_sub_and_fetch(pw, val);
}
template <class T>
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 */
// 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_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);
}