From 30418a47c609fdff286bcab4e29e3fe0b244632e Mon Sep 17 00:00:00 2001
From: Jeremy Allison <jra@samba.org>
Date: Wed, 23 Apr 2003 00:19:30 +0000
Subject: Limit the number of outstanding print notify messages for a process
 to 1000. Jeremy. (This used to be commit
 2e5e4c10d2377493913554e7dab79d97a4d16d87)

---
 source3/lib/messages.c    | 31 +++++++++++++++++++++++++++++++
 source3/printing/notify.c |  9 ++++++++-
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/source3/lib/messages.c b/source3/lib/messages.c
index 0615cc1883..8706ede706 100644
--- a/source3/lib/messages.c
+++ b/source3/lib/messages.c
@@ -303,6 +303,37 @@ BOOL message_send_pid_with_timeout(pid_t pid, int msg_type, const void *buf, siz
 	return message_send_pid_internal(pid, msg_type, buf, len, duplicates_allowed, timeout);
 }
 
+/****************************************************************************
+ Count the messages pending for a particular pid. Expensive....
+****************************************************************************/
+
+unsigned int messages_pending_for_pid(pid_t pid)
+{
+	TDB_DATA kbuf;
+	TDB_DATA dbuf;
+	char *buf;
+	unsigned int message_count = 0;
+
+	kbuf = message_key_pid(sys_getpid());
+
+	dbuf = tdb_fetch(tdb, kbuf);
+	if (dbuf.dptr == NULL || dbuf.dsize == 0) {
+		SAFE_FREE(dbuf.dptr);
+		return 0;
+	}
+
+	for (buf = dbuf.dptr; dbuf.dsize > sizeof(struct message_rec);) {
+		struct message_rec rec;
+		memcpy(&rec, buf, sizeof(rec));
+		buf += (sizeof(rec) + rec.len);
+		dbuf.dsize -= (sizeof(rec) + rec.len);
+		message_count++;
+	}
+
+	SAFE_FREE(dbuf.dptr);
+	return message_count;
+}
+
 /****************************************************************************
  Retrieve all messages for the current process.
 ****************************************************************************/
diff --git a/source3/printing/notify.c b/source3/printing/notify.c
index 428eb54ce4..ee973da211 100644
--- a/source3/printing/notify.c
+++ b/source3/printing/notify.c
@@ -174,8 +174,15 @@ static void print_notify_send_messages_to_printer(const char *printer, unsigned
 	if (!print_notify_pid_list(printer, send_ctx, &num_pids, &pid_list))
 		return;
 
-	for (i = 0; i < num_pids; i++)
+	for (i = 0; i < num_pids; i++) {
+		unsigned int q_len = messages_pending_for_pid(pid_list[i]);
+		if (q_len > 1000) {
+			DEBUG(5, ("print_notify_send_messages_to_printer: discarding notify to printer %s as queue length = %u\n",
+				printer, q_len ));
+			continue;
+		}
 		message_send_pid_with_timeout(pid_list[i], MSG_PRINTER_NOTIFY2, buf, offset, True, timeout);
+	}
 }
 
 /*******************************************************************
-- 
cgit