Two more sigprocmask questions

[Angus Leeming]

John, I think that the bodies of these functions should be wrapped 
inside sigprocmask calls so that the signal handler is not called 
unexpectedly. (generateChild contains the fork, execvp code).

Agree?

Questions.
1. In runBlocking, all SIGCHLD signals are blocked until after this 
particular child has died and been reaped. Am I corect to say that 
thereafter the signal handler will not receive a signal corresponding 
to this particular child?

2. In runNonBlocking(), all SIGCHLD signals are blocked until after we 
have performed some preliminary book-keeping in 
ForkedcallsController::addCall. Am I correct to say that thereafter 
the signal handler *will* receive a signal if the child failed to 
start (failed execvp) but will not receive a signal if the fork 
failed?

Angus

 // Wait for child process to finish.
 int ForkedProcess::runBlocking()
 {
+       sigset_t newMask, oldMask;
+
+       sigemptyset(&oldMask);
+       sigemptyset(&newMask);
+       sigaddset(&newMask, SIGCHLD);
+
+       sigprocmask(SIG_BLOCK, &newMask, &oldMask);
+
        retval_  = 0;
        pid_ = generateChild();
        if (pid_ <= 0) { // child or fork failed.
                retval_ = 1;
                return retval_;
        }

        retval_ = waitForChild();
+
+       sigprocmask(SIG_SETMASK, &oldMask, 0);
+
        return retval_;
}


 // Do not wait for child process to finish.
 int ForkedProcess::runNonBlocking()
 {
+       sigset_t newMask, oldMask;
+
+       sigemptyset(&oldMask);
+       sigemptyset(&newMask);
+       sigaddset(&newMask, SIGCHLD);
+
+       sigprocmask(SIG_BLOCK, &newMask, &oldMask);
+
        retval_ = 0;
        pid_ = generateChild();
        if (pid_ <= 0) { // child or fork failed.
                retval_ = 1;
                return retval_;
        }

        // Non-blocking execution.
        // Integrate into the Controller
        ForkedcallsController & contr = ForkedcallsController::get();
        contr.addCall(*this);
+
+       sigprocmask(SIG_SETMASK, &oldMask, 0);
+
        return retval_;
}