Signal.h

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/*
 * Copyright Onix Solutions Limited [OnixS]. All rights reserved.
 *
 * This software owned by Onix Solutions Limited [OnixS] and is protected by copyright law
 * and international copyright treaties.
 *
 * Access to and use of the software is governed by the terms of the applicable ONIXS Software
 * Services Agreement (the Agreement) and Customer end user license agreements granting
 * a non-assignable, non-transferable and non-exclusive license to use the software
 * for it's own data processing purposes under the terms defined in the Agreement.
 *
 * Except as otherwise granted within the terms of the Agreement, copying or reproduction of any part
 * of this source code or associated reference material to any other location for further reproduction
 * or redistribution, and any amendments to this copyright notice, are expressly prohibited.
 *
 * Any reproduction or redistribution for sale or hiring of the Software not in accordance with
 * the terms of the Agreement is a violation of copyright law.
 */
#pragma once
 
#include <OnixS/ICE/BOE/Compiler.h>
#include <OnixS/ICE/BOE/threading/Thread.h>
 
#include <csignal>
#include <atomic>
#include <string>
#include <sstream>
#include <iostream>
 
#ifdef _WIN32
#include <conio.h>
#else
#include <pthread.h>
#include <cstdlib>
#include <vector>
#include <sys/poll.h>
#endif
 
namespace Samples {

struct SignalHelper
{
    static void manageSignals() noexcept
    {
        manageSignalsImpl();
    }
 
    ONIXS_ICEBOE_FORCEINLINE
    static bool interruptDetected() noexcept
    {
        return interruptDetectedFlag().load(std::memory_order_relaxed);
    }
 
    static void waitUntilKey(const std::string& message)
    {
        std::clog << "\nPress <Ctrl+C> to " << message << ".." << std::endl;
 
        while(!interruptDetected())
            Threading::ThisThread::sleep(0);
    }
 
private:
    ONIXS_ICEBOE_FORCEINLINE
    static std::atomic<bool>& interruptDetectedFlag() noexcept
    {
        static std::atomic<bool> interruptDetected {false};
        return interruptDetected;
    }
 
#ifndef _WIN32
    [[noreturn]]
    static void errorAbort(int status, const char* reason)
    {
        std::cerr << "Aborted due to status " << status << ": " << (reason ? reason : "no error message") << std::endl;
        exit(1);
    }
 
    [[noreturn]]
    static void* signalWaiter(void* /*arg*/)
    {
        try {ONIXS_ICEBOE_NAMESPACE::Threading::ThisThread::affinity(0);} catch(...){}
 
        while (true)
        {
            int signalNumber;
            sigwait(&signalSet(), &signalNumber);
 
            if(signalNumber == SIGINT)
                 interruptDetectedFlag().store(true);
            else
                std::cerr << "Signal " << signalNumber << " received and suppressed." << std::endl;
        }
    }
 
    static void manageSignalsImpl() noexcept
    {
        constexpr int signals[] = { SIGINT, SIGPIPE };
 
        pthread_t signalThreadId;
 
        // Mask signals in the primary thread. Child threads will inherit this signal mask.
        sigemptyset(&signalSet());
        std::for_each(std::begin(signals), std::end(signals), [&](int signal){sigaddset(&signalSet(), signal);});
 
        {
            const auto status = pthread_sigmask(SIG_BLOCK, &signalSet(), nullptr);
            if (status != 0)
                errorAbort(status, "Set signal mask");
        }
        {
            const auto status = pthread_create(&signalThreadId, nullptr, signalWaiter, nullptr);
            if (status != 0)
                errorAbort(status, "Create signalWaiter");
        }
    }
 
    static sigset_t& signalSet() noexcept
    {
        static sigset_t set;
        return set;
    }
#else
    static void manageSignalsImpl() noexcept
    {
        signal(SIGINT, &SignalHelper::signalHandler);
    }
 
    static void signalHandler(int signal)
    {
        if (SIGINT == signal)
            interruptDetectedFlag().store(true);
    }
#endif
};
 
}