1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
// Copyright (c) 2015 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifndef BITCOIN_SCHEDULER_H
#define BITCOIN_SCHEDULER_H
//
// NOTE:
// boost::thread / boost::function / boost::chrono should be ported to
// std::thread / std::function / std::chrono when we support C++11.
//
#include <boost/chrono/chrono.hpp>
#include <boost/thread.hpp>
#include <map>
//
// Simple class for background tasks that should be run
// periodically or once "after a while"
//
// Usage:
//
// CScheduler* s = new CScheduler();
// s->scheduleFromNow(doSomething, 11); // Assuming a: void doSomething() { }
// s->scheduleFromNow(std::bind(Class::func, this, argument), 3);
// boost::thread* t = new boost::thread(boost::bind(CScheduler::serviceQueue, s));
//
// ... then at program shutdown, clean up the thread running serviceQueue:
// t->interrupt();
// t->join();
// delete t;
// delete s; // Must be done after thread is interrupted/joined.
//
class CScheduler
{
public:
CScheduler();
~CScheduler();
typedef std::function<void(void)> Function;
// Call func at/after time t
void schedule(Function f, boost::chrono::system_clock::time_point t);
// Convenience method: call f once deltaSeconds from now
void scheduleFromNow(Function f, int64_t deltaMilliSeconds);
// Another convenience method: call f approximately
// every deltaSeconds forever, starting deltaSeconds from now.
// To be more precise: every time f is finished, it
// is rescheduled to run deltaSeconds later. If you
// need more accurate scheduling, don't use this method.
void scheduleEvery(Function f, int64_t deltaMilliSeconds);
// To keep things as simple as possible, there is no unschedule.
// Services the queue 'forever'. Should be run in a thread,
// and interrupted using boost::interrupt_thread
void serviceQueue();
// Tell any threads running serviceQueue to stop as soon as they're
// done servicing whatever task they're currently servicing (drain=false)
// or when there is no work left to be done (drain=true)
void stop(bool drain=false);
// Returns number of tasks waiting to be serviced,
// and first and last task times
size_t getQueueInfo(boost::chrono::system_clock::time_point &first,
boost::chrono::system_clock::time_point &last) const;
private:
std::multimap<boost::chrono::system_clock::time_point, Function> taskQueue;
boost::condition_variable newTaskScheduled;
mutable boost::mutex newTaskMutex;
int nThreadsServicingQueue;
bool stopRequested;
bool stopWhenEmpty;
bool shouldStop() { return stopRequested || (stopWhenEmpty && taskQueue.empty()); }
};
#endif
|
