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/*************************************************************************/
/* safe_refcount.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur. */
/* */
/* 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
uint32_t atomic_conditional_increment(register uint32_t *pw) {
if (*pw == 0)
return 0;
(*pw)++;
return *pw;
}
uint32_t atomic_increment(register uint32_t *pw) {
(*pw)++;
return *pw;
}
uint32_t atomic_decrement(register uint32_t *pw) {
(*pw)--;
return *pw;
}
#else
#ifdef _MSC_VER
// don't pollute my namespace!
#include <windows.h>
uint32_t atomic_conditional_increment(register uint32_t *pw) {
/* try to increment until it actually works */
// taken from boost
while (true) {
uint32_t tmp = static_cast<uint32_t const volatile &>(*pw);
if (tmp == 0)
return 0; // if zero, can't add to it anymore
if (InterlockedCompareExchange((LONG volatile *)pw, tmp + 1, tmp) == tmp)
return tmp + 1;
}
}
uint32_t atomic_decrement(register uint32_t *pw) {
return InterlockedDecrement((LONG volatile *)pw);
}
uint32_t atomic_increment(register uint32_t *pw) {
return InterlockedIncrement((LONG volatile *)pw);
}
#elif defined(__GNUC__)
uint32_t atomic_conditional_increment(register uint32_t *pw) {
while (true) {
uint32_t tmp = static_cast<uint32_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;
}
}
uint32_t atomic_decrement(register uint32_t *pw) {
return __sync_sub_and_fetch(pw, 1);
}
uint32_t atomic_increment(register uint32_t *pw) {
return __sync_add_and_fetch(pw, 1);
}
#else
//no threads supported?
#error Must provide atomic functions for this platform or compiler!
#endif
#endif
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