lix/src/libutil/signals.hh
jade 8be7030299 util.hh: split out signals stuff
Copies part of the changes of ac89bb064aeea85a62b82a6daf0ecca7190a28b7

Change-Id: I9ce601875cd6d4db5eb1132d7835c5bab9f126d8
2024-03-11 00:52:09 -07:00

94 lines
2 KiB
C++

#pragma once
/// @file
#include "types.hh"
#include "error.hh"
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include <signal.h>
#include <atomic>
#include <functional>
#include <sstream>
namespace nix {
/* User interruption. */
extern std::atomic<bool> _isInterrupted;
extern thread_local std::function<bool()> interruptCheck;
void setInterruptThrown();
void _interrupted();
void inline checkInterrupt()
{
if (_isInterrupted || (interruptCheck && interruptCheck()))
_interrupted();
}
MakeError(Interrupted, BaseError);
void restoreSignals();
/**
* Start a thread that handles various signals. Also block those signals
* on the current thread (and thus any threads created by it).
* Saves the signal mask before changing the mask to block those signals.
* See saveSignalMask().
*/
void startSignalHandlerThread();
/**
* Saves the signal mask, which is the signal mask that nix will restore
* before creating child processes.
* See setChildSignalMask() to set an arbitrary signal mask instead of the
* current mask.
*/
void saveSignalMask();
/**
* Sets the signal mask. Like saveSignalMask() but for a signal set that doesn't
* necessarily match the current thread's mask.
* See saveSignalMask() to set the saved mask to the current mask.
*/
void setChildSignalMask(sigset_t *sigs);
struct InterruptCallback
{
virtual ~InterruptCallback() { };
};
/**
* Register a function that gets called on SIGINT (in a non-signal
* context).
*/
std::unique_ptr<InterruptCallback> createInterruptCallback(
std::function<void()> callback);
void triggerInterrupt();
/**
* A RAII class that causes the current thread to receive SIGUSR1 when
* the signal handler thread receives SIGINT. That is, this allows
* SIGINT to be multiplexed to multiple threads.
*/
struct ReceiveInterrupts
{
pthread_t target;
std::unique_ptr<InterruptCallback> callback;
ReceiveInterrupts()
: target(pthread_self())
, callback(createInterruptCallback([&]() { pthread_kill(target, SIGUSR1); }))
{ }
};
};