Explain postmaster's treatment of SIGURG.
Add a few words of comment to explain why SIGURG doesn't follow the
dummy_handler pattern used for SIGUSR2, since that might otherwise
appear to be a bug.
Discussion:
@@ -660,6 +660,11 @@ PostmasterMain(int argc, char *argv[])
pqsignal_pm(SIGCHLD, reaper); /* handle child termination */
#ifdef SIGURG
+ /*
+ * Ignore SIGURG for now. Child processes may change this (see
+ * InitializeLatchSupport), but they will not receive any such signals
+ * until they wait on a latch.
+ */
pqsignal_pm(SIGURG, SIG_IGN); /* ignored */
#endif
