9bb89ab323* Improve const correctness and adhere to 'const' specifier positioning style Co-authored-by: Mario Ortiz Manero <marioortizmanero@gmail.com>
79 lines
2.7 KiB
C++
79 lines
2.7 KiB
C++
#pragma once
|
|
|
|
#include <nano/lib/utility.hpp>
|
|
|
|
#include <boost/asio.hpp>
|
|
#include <boost/system/error_code.hpp>
|
|
#include <boost/thread.hpp>
|
|
|
|
#include <iostream>
|
|
#include <memory>
|
|
#include <string>
|
|
#include <vector>
|
|
|
|
namespace nano
|
|
{
|
|
/**
|
|
* Manages signal handling and allows to register custom handlers for any signal.
|
|
* IMPORTANT NOTE: only one instance of this class should be instantiated per process.
|
|
* IMPORTANT NOTE: this is an add-only class, there is currently no way to remove a handler,
|
|
although that functionality could be easily be added if needed.
|
|
*/
|
|
class signal_manager final
|
|
{
|
|
public:
|
|
/** The signal manager expects to have a boost asio context */
|
|
signal_manager ();
|
|
|
|
/** stops the signal manager io context and wait for the thread to finish */
|
|
~signal_manager ();
|
|
|
|
/** Register a handler for a signal to be called from a safe context.
|
|
* The handler will be called from the "ioc" io context.
|
|
*/
|
|
void register_signal_handler (int signum, std::function<void (int)> handler, bool repeat);
|
|
|
|
private:
|
|
struct signal_descriptor final
|
|
{
|
|
signal_descriptor (std::shared_ptr<boost::asio::signal_set> sigset_a, signal_manager & sigman_a, std::function<void (int)> handler_func_a, bool repeat_a);
|
|
|
|
/** a signal set that maps signals to signal handler and provides the connection to boost asio */
|
|
std::shared_ptr<boost::asio::signal_set> sigset;
|
|
|
|
/** reference to the signal manager that owns this signal descriptor */
|
|
signal_manager & sigman;
|
|
|
|
/** the caller supplied function to call from the base signal handler */
|
|
std::function<void (int)> handler_func;
|
|
|
|
/** indicates if the signal handler should continue handling a signal after receiving one */
|
|
bool repeat;
|
|
};
|
|
|
|
/**
|
|
* Logging function of signal manager. It does nothing at the moment, it throws away the log.
|
|
* I expect to revisit this in the future. It also makes it easy to manually introduce logs, if needed temporarily.
|
|
*/
|
|
void log (std::string const &){};
|
|
|
|
/**
|
|
* This is the actual handler that is registered with boost asio.
|
|
* It calls the caller supplied function (if one is given) and sets the handler to repeat (or not).
|
|
*/
|
|
static void base_handler (nano::signal_manager::signal_descriptor descriptor, boost::system::error_code const & error, int signum);
|
|
|
|
/** boost asio context to use */
|
|
boost::asio::io_context ioc;
|
|
|
|
/** work object to make the thread run function live as long as a signal manager */
|
|
boost::asio::executor_work_guard<boost::asio::io_context::executor_type> work;
|
|
|
|
/** a list of descriptors to hold data contexts needed by the asyncronous handlers */
|
|
std::vector<signal_descriptor> descriptor_list;
|
|
|
|
/** thread to service the signal manager io context */
|
|
boost::thread smthread;
|
|
};
|
|
|
|
}
|