very simple asynchronous "lpq" thread patch

To speed up operations with the lpq command, it's now run in a separate
asynchronous process.

Opening the Printers folder on NT is now fast ;-) I think even faster than
with a ** server

Jeremy, you should look at that patch to include it in 2.2.3

	J.F.
(This used to be commit 8ef9dff3074e7979579ce66a204e8ec7bf62a587)

3 files changed, 53 insertions, 2 deletions

diff --git a/source3/include/messages.h b/source3/include/messages.h
index cc10f3b90bb..dfbc4862117 100644
--- a/source3/include/messages.h
+++ b/source3/include/messages.h
@@ -37,6 +37,7 @@
 
 /* rpc messages */
 #define MSG_PRINTER_NOTIFY 2001
+#define MSG_PRINTER_UPDATE 2002
 
 /* smbd messages */
 #define MSG_SMB_CONF_UPDATED 3001
diff --git a/source3/printing/printing.c b/source3/printing/printing.c
index 9135cb2d5ef..db675853327 100644
--- a/source3/printing/printing.c
+++ b/source3/printing/printing.c
@@ -311,10 +311,10 @@ static void set_updating_pid(fstring printer_name, BOOL delete)
 }
 
 /****************************************************************************
-update the internal database from the system print queue for a queue
+update the internal database from the system print queue for a queue in the background
 ****************************************************************************/
 
-static void print_queue_update(int snum)
+static void print_queue_update_background(int snum)
 {
 	int i, qcount;
 	print_queue_struct *queue = NULL;
@@ -468,6 +468,54 @@ static void print_queue_update(int snum)
 }
 
 /****************************************************************************
+this is the receive function of the background lpq updater
+****************************************************************************/
+static void print_queue_receive(int msg_type, pid_t src, void *buf, size_t len)
+{
+	int snum;
+	snum=*((int *)buf);
+	print_queue_update_background(snum);
+}
+
+/****************************************************************************
+main thread of the background lpq updater
+****************************************************************************/
+void start_background_queue(void)
+{
+	DEBUG(3,("Starting background LPQ thread\n"));
+	if(sys_fork()==0) {
+		DEBUG(5,("background LPQ thread started\n"));
+
+		claim_connection(NULL,"smbd lpq backend",MAXSTATUS,False);
+
+		if (!locking_init(0)) {
+			exit(1);
+		}
+
+		if (!print_backend_init()) {
+			exit(1);
+		}
+
+		message_register(MSG_PRINTER_UPDATE, print_queue_receive);
+		
+		DEBUG(5,("background LPQ thread waiting for messages\n"));
+		while (1) {
+			pause();
+			DEBUG(10,("background LPQ thread got a message\n"));
+			message_dispatch();
+		}
+	}
+}
+
+/****************************************************************************
+update the internal database from the system print queue for a queue
+****************************************************************************/
+static void print_queue_update(int snum)
+{
+	message_send_all(conn_tdb_ctx(), MSG_PRINTER_UPDATE, &snum, sizeof(snum), False);
+}
+
+/****************************************************************************
 check if a jobid is valid. It is valid if it exists in the database
 ****************************************************************************/
 BOOL print_job_exists(int jobid)
diff --git a/source3/smbd/server.c b/source3/smbd/server.c
index f707a61376e..4599cef41fb 100644
--- a/source3/smbd/server.c
+++ b/source3/smbd/server.c
@@ -791,6 +791,8 @@ static void usage(char *pname)
 	/* Setup the main smbd so that we can get messages. */
 	claim_connection(NULL,"",MAXSTATUS,True);
 
+	start_background_queue();
+
 	if (!open_sockets(is_daemon,port))
 		exit(1);