Restoring original signal in sigaction

I have sigaction defined and it works fine. However I want to restore the original signal after my act开发者_StackOverflowion is completed. This is my sigaction:

static void signal_handler(int signal, siginfo_t *info, void *reserved)
{
    //Some logging statements
    //How do I restore the original signal here??
}

The signal handler is set from JNI_Onload:

extern "C" jint JNI_OnLoad(JavaVM* vm, void* /*reserved*/)
{
    struct sigaction handler, action_old;
    memset(&handler, 0, sizeof(handler));
    handler.sa_sigaction = signal_handler;
    handler.sa_flags = SA_SIGINFO;
    sigaction(SIGILL, &handler, &action_old);
    sigaction(SIGABRT, &handler, &action_old);
    sigaction(SIGBUS, &handler, &action_old);
    sigaction(SIGFPE, &handler, &action_old);
    sigaction(SIGSEGV, &handler, &action_old);
    sigaction(SIGSTKFLT, &handler, &action_old);

    //Can I restore prior signal here???

    return JNI_VERSION_1_6;
}

Save the old actions in global (or file-scope) variables (or an array indexed by signal id) and call sigaction from inside your signal handler to restore the previous behavior. sigaction is guaranteed to be async-signal safe.

See also: http://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_04_03

http://www.gnu.org/s/hello/manual/libc/Basic-Signal-Handling.html - says:

The signal function returns the action that was previously in effect for the specified signum. You can save this value and restore it later by calling signal again.