116 lines
3.8 KiB
C++
116 lines
3.8 KiB
C++
/*************************************************************************/
|
|
/* safe_refcount.cpp */
|
|
/*************************************************************************/
|
|
/* This file is part of: */
|
|
/* GODOT ENGINE */
|
|
/* http://www.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
|
|
|
|
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
|