[PATCH 8/8] oxenstored: fine tunning the recognition of domain connections with queued input/output

[Zheng Li <dev@zheng.li>]

... also, only try to input on a connection with queued input, ditto for output.

Signed-off-by: Zheng Li <dev@zheng.li>
---
 tools/ocaml/xenstored/connection.ml  |  1 +
 tools/ocaml/xenstored/connections.ml | 14 +++++++++-----
 tools/ocaml/xenstored/xenstored.ml   |  7 ++++---
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/tools/ocaml/xenstored/connection.ml b/tools/ocaml/xenstored/connection.ml
index 47695f8..1769e23 100644
--- a/tools/ocaml/xenstored/connection.ml
+++ b/tools/ocaml/xenstored/connection.ml
@@ -223,6 +223,7 @@ let pop_in con = Xenbus.Xb.get_in_packet con.xb
 let has_more_input con = Xenbus.Xb.has_more_input con.xb
 
 let has_output con = Xenbus.Xb.has_output con.xb
+let has_old_output con = Xenbus.Xb.has_old_output con.xb
 let has_new_output con = Xenbus.Xb.has_new_output con.xb
 let peek_output con = Xenbus.Xb.peek_output con.xb
 let do_output con = Xenbus.Xb.output con.xb
diff --git a/tools/ocaml/xenstored/connections.ml b/tools/ocaml/xenstored/connections.ml
index a0f1b89..1baa6c3 100644
--- a/tools/ocaml/xenstored/connections.ml
+++ b/tools/ocaml/xenstored/connections.ml
@@ -93,11 +93,15 @@ let iter cons fct =
 	iter_domains cons fct; iter_anonymous cons fct
 
 let has_more_work cons =
-	Hashtbl.fold (fun id con acc ->
-		if Connection.has_more_input con then
-			con :: acc
-		else
-			acc) cons.domains []
+	Hashtbl.fold
+		(fun id con (racc, wacc) ->
+		 (if Connection.has_more_input con
+		  then con :: racc else racc),
+		 (if (* not currently blocked by filled up ring *)
+                    not (Connection.has_old_output con)
+		    && Connection.has_new_output con
+		  then con :: wacc else wacc))
+		cons.domains ([],[])
 
 let key_of_str path =
 	if path.[0] = '@'
diff --git a/tools/ocaml/xenstored/xenstored.ml b/tools/ocaml/xenstored/xenstored.ml
index 41a188d..b95232c 100644
--- a/tools/ocaml/xenstored/xenstored.ml
+++ b/tools/ocaml/xenstored/xenstored.ml
@@ -376,9 +376,9 @@ let _ =
 			periodic_ops ();
 		);
 
-		let mw = Connections.has_more_work cons in
+		let rmw, wmw = Connections.has_more_work cons in
+		let timeout = if List.length rmw > 0 || List.length wmw > 0 then 0. else -1. in
 		let inset, outset = Connections.select cons in
-		let timeout = if List.length mw > 0 then 0. else -1. in
 		let rset, wset, _ =
 		try
 			Select.select (spec_fds @ inset) outset [] timeout
@@ -390,7 +390,8 @@ let _ =
 			process_special_fds sfds;
 		if List.length cfds > 0 || List.length wset > 0 then
 			process_connection_fds store cons domains cfds wset;
-		List.iter (process_domain store cons domains) mw
+		List.iter (process_domain ~mode_switch:true store cons domains) rmw;
+		List.iter (process_domain ~mode_switch:false store cons domains) wmw
 		in
 
 	while not !quit
-- 
2.1.0