/*************************************************************************/
/*  thread_local.cpp                                                     */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2021 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 "thread_local.h"

#ifdef WINDOWS_ENABLED
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#else
#include <pthread.h>
#endif

#include "core/os/memory.h"
#include "core/print_string.h"

struct ThreadLocalStorage::Impl {
#ifdef WINDOWS_ENABLED
	DWORD dwFlsIndex;
#else
	pthread_key_t key;
#endif

	void *get_value() const {
#ifdef WINDOWS_ENABLED
		return FlsGetValue(dwFlsIndex);
#else
		return pthread_getspecific(key);
#endif
	}

	void set_value(void *p_value) const {
#ifdef WINDOWS_ENABLED
		FlsSetValue(dwFlsIndex, p_value);
#else
		pthread_setspecific(key, p_value);
#endif
	}

#ifdef WINDOWS_ENABLED
#define _CALLBACK_FUNC_ __stdcall
#else
#define _CALLBACK_FUNC_
#endif

	Impl(void(_CALLBACK_FUNC_ *p_destr_callback_func)(void *)) {
#ifdef WINDOWS_ENABLED
		dwFlsIndex = FlsAlloc(p_destr_callback_func);
		ERR_FAIL_COND(dwFlsIndex == FLS_OUT_OF_INDEXES);
#else
		pthread_key_create(&key, p_destr_callback_func);
#endif
	}

	~Impl() {
#ifdef WINDOWS_ENABLED
		FlsFree(dwFlsIndex);
#else
		pthread_key_delete(key);
#endif
	}
};

void *ThreadLocalStorage::get_value() const {
	return pimpl->get_value();
}

void ThreadLocalStorage::set_value(void *p_value) const {
	pimpl->set_value(p_value);
}

void ThreadLocalStorage::alloc(void(_CALLBACK_FUNC_ *p_destr_callback)(void *)) {
	pimpl = memnew(ThreadLocalStorage::Impl(p_destr_callback));
}

#undef _CALLBACK_FUNC_

void ThreadLocalStorage::free() {
	memdelete(pimpl);
	pimpl = NULL;
}