Hello all,
While executing system call, If signal occurs, then kernel take one of
the two actions,
1) If a signal arrived while we were executing kernel code, then just
before returning from the system call we first call the user program's
signal handler, and when this finishes return from the system call.
2) When a system call is slow and a signal arrives while it was
blocked, waiting for something, the call is aborted and returns -EINTR, so
that the library function will return -1 and set errorno to EINTR.Just
before the system call returns, the user program's signal handler is called.
In second case, I am not understanding that why not system call execution is
restarted by default, once handler get executed? I know that can be
automated by installing the signal handler using a call to sigaction with
the SA_RESTART flag set, but why not it is default?
Regards,
Shyam.
