Currently if we max out the maximum number of files, pseudo can deadlock, unable to
accept new connections yet unable to move forward and unblock the other processes
waiting either.

Rather than hang, when this happens, close out inactive connections, allowing us
to accept the new ones. The disconnected clients will simply reconnect. There is
a small risk of data loss here sadly but its better than hanging.

RP
2017/4/25

Upstream-Status: Submitted [Peter is aware of the issue]

Index: pseudo-1.8.2/pseudo_server.c
===================================================================
--- pseudo-1.8.2.orig/pseudo_server.c
+++ pseudo-1.8.2/pseudo_server.c
@@ -581,6 +581,7 @@ pseudo_server_loop(void) {
 	int rc;
 	int fd;
 	int loop_timeout = pseudo_server_timeout;
+	int hitmaxfiles;
 
 	clients = malloc(16 * sizeof(*clients));
 
@@ -597,6 +598,7 @@ pseudo_server_loop(void) {
 	active_clients = 1;
 	max_clients = 16;
 	highest_client = 0;
+	hitmaxfiles = 0;
 
 	pseudo_debug(PDBGF_SERVER, "server loop started.\n");
 	if (listen_fd < 0) {
@@ -663,10 +665,15 @@ pseudo_server_loop(void) {
 						message_time.tv_usec -= 1000000;
 						++message_time.tv_sec;
 					}
+				} else if (hitmaxfiles) {
+					/* Only close one per loop iteration in the interests of caution */
+					close_client(i);
+					hitmaxfiles = 0;
 				}
 				if (die_forcefully)
 					break;
 			}
+			hitmaxfiles = 0;
 			if (!die_forcefully && 
 			    (FD_ISSET(clients[0].fd, &events) ||
 			     FD_ISSET(clients[0].fd, &reads))) {
@@ -688,6 +698,9 @@ pseudo_server_loop(void) {
                                          */
                                         pseudo_server_timeout = DEFAULT_PSEUDO_SERVER_TIMEOUT;
                                         die_peacefully = 0;
+				} else if (errno == EMFILE) {
+					hitmaxfiles = 1;
+					pseudo_debug(PDBGF_SERVER, "Hit max open files, dropping a client.\n");
 				}
 			}
 			pseudo_debug(PDBGF_SERVER, "server loop complete [%d clients left]\n", active_clients);