In founction ServerLoop() in code postmaster.c, after select(), we called PG_SETMASK(). If l add an elog() after PG_SETMASK(), I see errno is reset to 0 when PG_SETMASK() call suceeded. But the immediately code will actually check errno from the select() call which now has been overwritten by PG_SETMASK().
Can someone share some light on this?
Thanks
Congnan