Re: [HACKERS] [PATCHES] fork/exec patch

Tom Lane wrote:
> "Magnus Hagander" <mha@sollentuna.net> writes:
> > Well. There is one in the form of "make signal handlers thread-safe or
> > defer non-threadsafe handlers".
>
> As long as there is only one thread that can invoke signal handlers,
> I don't see why you think they need to be "thread-safe".
>
> It's already the case that we either handle execution of a signal
> handler everywhere, or block delivery of the signal where we can't
> handle it, because in the Unix model a signal handler can execute
> anytime.
>
> I'd be more concerned about whether the proposed implementation accurately
> models signal mask processing (ie, temporary blocking of signal delivery).

On the Win32 project page:

    http://momjian.postgresql.org/main/writings/pgsql/project/win32.html

I see for the CONNX driver code that handles signal masking:

    /*
      The sigsetmask system call replaces  the  set  of  blocked
      signals totally with a new set specified in mask.  Signals
      are blocked if the corresponding bit in mask is a 1.
    */

    int             sigsetmask(int nNewMask)
    {
        int             nPreviousMask = nGlobalSignalMask;
        nGlobalSignalMask = nNewMask;
        return nPreviousMask;
    }

    int             sigmask(int nSignal)
    {
        return 1 << ((nSignal) - 1);
    }

    CONNX_signal_function CONNX_signal(int sig, CONNX_signal_function func)
    {
        CONNX_signal_function oldfunc;
        oldfunc = CONNX_signal_array[sig];
        CONNX_signal_array[sig] = func;
        return oldfunc;
    }


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