Here, we are not using the SA_NODEFER signal flag. So, when the first instance of signal n arrives, our process jumps into the signal-handling code (which will take 55 ms to complete). However, the second signal will arrive just 10 ms into the signal handling code. But, hang on, it's auto-masked! Hence, we will not process it. In fact, a simple calculation will show that up to five instances of signal n will reach our process in the 55-ms signal handling time frame:
Figure 3: Default behavior: SA_NODEFER bit cleared: no queue, one signal instance pending delivery, no real impact on stack
So, what exactly ...
