bitcoin/src/util/threadinterrupt.h

59 lines
1.7 KiB
C++

// Copyright (c) 2016-2022 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_UTIL_THREADINTERRUPT_H
#define BITCOIN_UTIL_THREADINTERRUPT_H
#include <sync.h>
#include <threadsafety.h>
#include <atomic>
#include <chrono>
#include <condition_variable>
/**
* A helper class for interruptible sleeps. Calling operator() will interrupt
* any current sleep, and after that point operator bool() will return true
* until reset.
*
* This class should not be used in a signal handler. It uses thread
* synchronization primitives that are not safe to use with signals. If sending
* an interrupt from a signal handler is necessary, the \ref SignalInterrupt
* class can be used instead.
*/
class CThreadInterrupt
{
public:
using Clock = std::chrono::steady_clock;
CThreadInterrupt();
virtual ~CThreadInterrupt() = default;
/// Return true if `operator()()` has been called.
virtual bool interrupted() const;
/// An alias for `interrupted()`.
virtual explicit operator bool() const;
/// Interrupt any sleeps. After this `interrupted()` will return `true`.
virtual void operator()() EXCLUSIVE_LOCKS_REQUIRED(!mut);
/// Reset to an non-interrupted state.
virtual void reset();
/// Sleep for the given duration.
/// @retval true The time passed.
/// @retval false The sleep was interrupted.
virtual bool sleep_for(Clock::duration rel_time) EXCLUSIVE_LOCKS_REQUIRED(!mut);
private:
std::condition_variable cond;
Mutex mut;
std::atomic<bool> flag;
};
#endif // BITCOIN_UTIL_THREADINTERRUPT_H