1 /* 2 * A page queue abstraction. 3 * 4 * Copyright (C) 2021, 2022 Paul Boddie <paul@boddie.org.uk> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation; either version 2 of 9 * the License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, 19 * Boston, MA 02110-1301, USA 20 */ 21 22 #pragma once 23 24 #include <list> 25 26 #include <mem/flexpage.h> 27 #include <mem/memory.h> 28 #include <fsserver/page_owner.h> 29 30 31 32 /* Collection types. */ 33 34 typedef struct { Flexpage *flexpage; PageOwner *owner; } QueueEntry; 35 typedef std::list<QueueEntry> Queue; 36 37 38 39 /* A queue of managed pages. */ 40 41 class PageQueue 42 { 43 protected: 44 /* Helper methods. */ 45 46 virtual void discard(Queue &queue, Memory *memory); 47 48 public: 49 virtual ~PageQueue(); 50 51 virtual void close(Memory *memory) = 0; 52 53 virtual void pop(PageOwner **owner, Flexpage **flexpage) = 0; 54 55 virtual void push(PageOwner *owner, Flexpage *flexpage) = 0; 56 57 virtual void push_front(PageOwner *owner, Flexpage *flexpage) = 0; 58 59 virtual bool remove(PageOwner *owner, Flexpage *flexpage) = 0; 60 }; 61 62 // vim: tabstop=4 expandtab shiftwidth=4