[Qemu-devel] [PATCH 02/10] qdev: change iterator callback seq

[Liu Ping Fan <qemulist@gmail.com>]

From: Liu Ping Fan <pingfank@linux.vnet.ibm.com>

Some func should be called after iteration over object's children,
for example, func will put ref of object.

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
---
 hw/qdev.c |   30 ++++++++++++++++++++++--------
 hw/qdev.h |    4 ++--
 2 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/hw/qdev.c b/hw/qdev.c
index b5b74b9..ad618dd 100644
--- a/hw/qdev.c
+++ b/hw/qdev.c
@@ -230,13 +230,13 @@ static int qbus_reset_one(BusState *bus, void *opaque)
 
 void qdev_reset_all(DeviceState *dev)
 {
-    qdev_walk_children(dev, qdev_reset_one, qbus_reset_one, NULL);
+    qdev_walk_children(dev, qdev_reset_one, qbus_reset_one, NULL, 0);
 }
 
 void qbus_reset_all_fn(void *opaque)
 {
     BusState *bus = opaque;
-    qbus_walk_children(bus, qdev_reset_one, qbus_reset_one, NULL);
+    qbus_walk_children(bus, qdev_reset_one, qbus_reset_one, NULL, 0);
 }
 
 /* can be used as ->unplug() callback for the simple cases */
@@ -342,12 +342,12 @@ BusState *qdev_get_child_bus(DeviceState *dev, const char *name)
 }
 
 int qbus_walk_children(BusState *bus, qdev_walkerfn *devfn,
-                       qbus_walkerfn *busfn, void *opaque)
+                       qbus_walkerfn *busfn, void *opaque, int after)
 {
     BusChild *kid;
     int err;
 
-    if (busfn) {
+    if ((after == 0) && busfn) {
         err = busfn(bus, opaque);
         if (err) {
             return err;
@@ -355,22 +355,29 @@ int qbus_walk_children(BusState *bus, qdev_walkerfn *devfn,
     }
 
     QTAILQ_FOREACH(kid, &bus->children, sibling) {
-        err = qdev_walk_children(kid->child, devfn, busfn, opaque);
+        err = qdev_walk_children(kid->child, devfn, busfn, opaque, after);
         if (err < 0) {
             return err;
         }
     }
 
+    if ((after != 0) && busfn) {
+        err = busfn(bus, opaque);
+        if (err) {
+            return err;
+        }
+    }
+
     return 0;
 }
 
 int qdev_walk_children(DeviceState *dev, qdev_walkerfn *devfn,
-                       qbus_walkerfn *busfn, void *opaque)
+                       qbus_walkerfn *busfn, void *opaque, int after)
 {
     BusState *bus;
     int err;
 
-    if (devfn) {
+    if ((after == 0) && devfn) {
         err = devfn(dev, opaque);
         if (err) {
             return err;
@@ -378,12 +385,19 @@ int qdev_walk_children(DeviceState *dev, qdev_walkerfn *devfn,
     }
 
     QLIST_FOREACH(bus, &dev->child_bus, sibling) {
-        err = qbus_walk_children(bus, devfn, busfn, opaque);
+        err = qbus_walk_children(bus, devfn, busfn, opaque, after);
         if (err < 0) {
             return err;
         }
     }
 
+    if ((after != 0) && devfn) {
+        err = devfn(dev, opaque);
+        if (err) {
+            return err;
+        }
+    }
+
     return 0;
 }
 
diff --git a/hw/qdev.h b/hw/qdev.h
index d699194..9fc8b46 100644
--- a/hw/qdev.h
+++ b/hw/qdev.h
@@ -195,9 +195,9 @@ BusState *qbus_create(const char *typename, DeviceState *parent, const char *nam
  *         < 0 if either devfn or busfn terminate walk somewhere in cursion,
  *           0 otherwise. */
 int qbus_walk_children(BusState *bus, qdev_walkerfn *devfn,
-                       qbus_walkerfn *busfn, void *opaque);
+                       qbus_walkerfn *busfn, void *opaque, int after);
 int qdev_walk_children(DeviceState *dev, qdev_walkerfn *devfn,
-                       qbus_walkerfn *busfn, void *opaque);
+                       qbus_walkerfn *busfn, void *opaque, int after);
 void qdev_reset_all(DeviceState *dev);
 void qbus_reset_all_fn(void *opaque);
 
-- 
1.7.4.4