1// workqueue-internal.h -- internal work queue header for gold   -*- C++ -*-
2
3// Copyright (C) 2006-2017 Free Software Foundation, Inc.
4// Written by Ian Lance Taylor <iant@google.com>.
5
6// This file is part of gold.
7
8// This program is free software; you can redistribute it and/or modify
9// it under the terms of the GNU General Public License as published by
10// the Free Software Foundation; either version 3 of the License, or
11// (at your option) any later version.
12
13// This program is distributed in the hope that it will be useful,
14// but WITHOUT ANY WARRANTY; without even the implied warranty of
15// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16// GNU General Public License for more details.
17
18// You should have received a copy of the GNU General Public License
19// along with this program; if not, write to the Free Software
20// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21// MA 02110-1301, USA.
22
23#ifndef GOLD_WORKQUEUE_INTERNAL_H
24#define GOLD_WORKQUEUE_INTERNAL_H
25
26#include <queue>
27#include <csignal>
28
29#include "gold-threads.h"
30#include "workqueue.h"
31
32// This is an internal header file for different gold workqueue
33// implementations.
34
35namespace gold
36{
37
38class Workqueue_thread;
39
40// The Workqueue_threader abstract class.  This is the interface used
41// by the general workqueue code to manage threads.
42
43class Workqueue_threader
44{
45 public:
46  Workqueue_threader(Workqueue* workqueue)
47    : workqueue_(workqueue)
48  { }
49  virtual ~Workqueue_threader()
50  { }
51
52  // Set the number of threads to use.  This is ignored when not using
53  // threads.
54  virtual void
55  set_thread_count(int) = 0;
56
57  // Return whether to cancel the current thread.
58  virtual bool
59  should_cancel_thread(int thread_number) = 0;
60
61 protected:
62  // Get the Workqueue.
63  Workqueue*
64  get_workqueue()
65  { return this->workqueue_; }
66
67 private:
68  // The Workqueue.
69  Workqueue* workqueue_;
70};
71
72// The threaded instantiation of Workqueue_threader.
73
74class Workqueue_threader_threadpool : public Workqueue_threader
75{
76 public:
77  Workqueue_threader_threadpool(Workqueue*);
78
79  ~Workqueue_threader_threadpool();
80
81  // Set the thread count.
82  void
83  set_thread_count(int);
84
85  // Return whether to cancel a thread.
86  bool
87  should_cancel_thread(int thread_number);
88
89  // Process all tasks.  This keeps running until told to cancel.
90  void
91  process(int thread_number)
92  { this->get_workqueue()->process(thread_number); }
93
94 private:
95  // This is set if we need to check the thread count.
96  volatile sig_atomic_t check_thread_count_;
97
98  // Lock for the remaining members.
99  Lock lock_;
100  // The number of threads we want to create.  This is set to zero
101  // when all threads should exit.
102  int desired_thread_count_;
103  // The number of threads currently running.
104  int threads_;
105};
106
107} // End namespace gold.
108
109#endif // !defined(GOLD_WORKQUEUE_INTERNAL_H)
110