Throwing an exception from within a signal handler

Question

We have a library that deals with many aspects of error reporting. I have been tasked to port this library to Linux. When running though my little test suite, one of the

Answer 1

This code demonstrates a technique which moves the throwing of the exception out of the signal handler into the code. My thanks to Charles for the idea.

#include 
#include 
#include 

using namespace std;

jmp_buf gBuffer;        // A buffer to hold info on where to jump to

void catch_signal(int signalNumber)
{
    //signal(SIGINT, SIG_DFL);          // Switch to default handling
    signal(SIGINT, catch_signal);       // Reactivate this handler.

    longjmp             // Jump back into the normal flow of the program
    (
        gBuffer,        // using this context to say where to jump to
        signalNumber    // and passing back the value of the signal.
    );
}


int test_signal()
{
    signal(SIGINT, catch_signal);

    try
    {
        int sig;
        if ((sig = setjmp(gBuffer)) == 0) 
        {
            cout << "before raise\n";
            raise(SIGINT);
            cout << "after raise\n";

        }
        else
        {
            // This path implies that a signal was thrown, and
            // that the setjmp function returned the signal
            // which puts use at this point.

            // Now that we are out of the signal handler it is
            // normally safe to throw what ever sort of exception we want.
            throw(sig);
        }
    }
    catch (int &z)
    {
        cerr << "Caught exception: " << z << endl;
    }

    return 0;
}

int main()
{
    try
    {
        test_signal();
    }
    catch (int &z)
    {
        cerr << "Caught unexpected exception: " << z << endl;
    }
    return 0;
}