/**************************************************************************/
/*  thread_work_pool.cpp                                                  */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 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:                                              */
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/* The above copyright notice and this permission notice shall be         */
/* included in all copies or substantial portions of the Software.        */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
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/**************************************************************************/

#include "thread_work_pool.h"

#include "core/os/os.h"

void ThreadWorkPool::_thread_function(void *p_user) {
	ThreadData *thread = static_cast<ThreadData *>(p_user);
	while (true) {
		thread->start.wait();
		if (thread->exit.load()) {
			break;
		}
		thread->work->work();
		thread->completed.post();
	}
}

void ThreadWorkPool::init(int p_thread_count) {
	ERR_FAIL_COND(threads != nullptr);
	if (p_thread_count < 0) {
		p_thread_count = OS::get_singleton()->get_default_thread_pool_size();
	}

	thread_count = p_thread_count;
	threads = memnew_arr(ThreadData, thread_count);

	for (uint32_t i = 0; i < thread_count; i++) {
		threads[i].exit.store(false);
		threads[i].thread.start(&ThreadWorkPool::_thread_function, &threads[i]);
	}
}

void ThreadWorkPool::finish() {
	if (threads == nullptr) {
		return;
	}

	for (uint32_t i = 0; i < thread_count; i++) {
		threads[i].exit.store(true);
		threads[i].start.post();
	}
	for (uint32_t i = 0; i < thread_count; i++) {
		threads[i].thread.wait_to_finish();
	}

	memdelete_arr(threads);
	threads = nullptr;
}

ThreadWorkPool::~ThreadWorkPool() {
	finish();
}