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Diffstat (limited to 'src/scheduler.h')
-rw-r--r-- | src/scheduler.h | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/src/scheduler.h b/src/scheduler.h new file mode 100644 index 0000000000..436659e58b --- /dev/null +++ b/src/scheduler.h @@ -0,0 +1,83 @@ +// 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/function.hpp> +#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(boost::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 boost::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 deltaSeconds); + + // 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 deltaSeconds); + + // 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 |