73 lines
2.3 KiB
C++
73 lines
2.3 KiB
C++
// @file task.h
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/**
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* Copyright (C) 2008 10gen Inc.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License, version 3,
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,b
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#pragma once
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#include "../background.h"
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namespace mongo {
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namespace task {
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/** abstraction around threads. simpler than BackgroundJob which is used behind the scenes.
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a shared_ptr is kept to the task - both by the task while running and the caller. that way
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the task object gets cleaned up once the last reference goes away.
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*/
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class Task : private BackgroundJob {
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protected:
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virtual void doWork() = 0; // implement the task here.
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virtual string name() = 0; // name the threada
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public:
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Task();
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/** for a repeating task, stop after current invocation ends. */
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void halt();
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private:
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shared_ptr<Task> me;
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unsigned n, repeat;
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friend void fork(shared_ptr<Task> t);
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friend void repeat(shared_ptr<Task> t, unsigned millis);
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virtual void run();
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virtual void ending();
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void begin(shared_ptr<Task>);
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};
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/** run once */
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void fork(shared_ptr<Task> t);
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/** run doWork() over and over, with a pause between runs of millis */
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void repeat(shared_ptr<Task> t, unsigned millis);
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/*** Example ***
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inline void sample() {
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class Sample : public Task {
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public:
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int result;
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virtual void doWork() { result = 1234; }
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Sample() : result(0) { }
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};
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shared_ptr<Sample> q( new Sample() );
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fork(q);
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cout << q->result << endl; // could print 1234 or 0.
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}
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*/
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}
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}
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