// workqueue-internal.h -- internal work queue header for gold -*- C++ -*-

// workqueue-internal.h -- internal work queue header for gold -*- C++ -*-

// Copyright (C) 2006-2024 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <[email protected]>.

// This file is part of gold.

// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.

#ifndef GOLD_WORKQUEUE_INTERNAL_H
#define GOLD_WORKQUEUE_INTERNAL_H

#include <queue>
#include <csignal>

#include "gold-threads.h"
#include "workqueue.h"

// This is an internal header file for different gold workqueue
// implementations.

namespace gold
{

class Workqueue_thread;

// The Workqueue_threader abstract class. This is the interface used
// by the general workqueue code to manage threads.

class Workqueue_threader
{
public:
Workqueue_threader(Workqueue* workqueue)
: workqueue_(workqueue)
{ }
virtual ~Workqueue_threader()
{ }

// Set the number of threads to use. This is ignored when not using
// threads.
virtual void
set_thread_count(int) = 0;

// Return whether to cancel the current thread.
virtual bool
should_cancel_thread(int thread_number) = 0;

protected:
// Get the Workqueue.
Workqueue*
get_workqueue()
{ return this->workqueue_; }

private:
// The Workqueue.
Workqueue* workqueue_;
};

// The threaded instantiation of Workqueue_threader.

class Workqueue_threader_threadpool : public Workqueue_threader
{
public:
Workqueue_threader_threadpool(Workqueue*);

~Workqueue_threader_threadpool();

// Set the thread count.
void
set_thread_count(int);

// Return whether to cancel a thread.
bool
should_cancel_thread(int thread_number);

// Process all tasks. This keeps running until told to cancel.
void
process(int thread_number)
{ this->get_workqueue()->process(thread_number); }

private:
// This is set if we need to check the thread count.
volatile sig_atomic_t check_thread_count_;

// Lock for the remaining members.
Lock lock_;
// The number of threads we want to create. This is set to zero
// when all threads should exit.
int desired_thread_count_;
// The number of threads currently running.
int threads_;
};

} // End namespace gold.

#endif // !defined(GOLD_WORKQUEUE_INTERNAL_H)