[ovs-dev] [bug 7550 2/9] ofproto: Make ofproto ->construct() function initialize tables.

[Ben Pfaff]

If the ->construct() function initializes the OpenFlow tables itself,
then it can conveniently do implementation-specific configuration of
those tables afterward.  There isn't any such configuration to do yet;
an upcoming commit will add some.

Signed-off-by: Ben Pfaff <blp at nicira.com>
---
 ofproto/ofproto-dpif.c     |    7 ++++---
 ofproto/ofproto-provider.h |   17 ++++++++---------
 ofproto/ofproto.c          |   26 +++++++++++++++++---------
 3 files changed, 29 insertions(+), 21 deletions(-)

diff --git a/ofproto/ofproto-dpif.c b/ofproto/ofproto-dpif.c
index b6c1087..d727781 100644
--- a/ofproto/ofproto-dpif.c
+++ b/ofproto/ofproto-dpif.c
@@ -611,7 +611,7 @@ dealloc(struct ofproto *ofproto_)
 }
 
 static int
-construct(struct ofproto *ofproto_, int *n_tablesp)
+construct(struct ofproto *ofproto_)
 {
     struct ofproto_dpif *ofproto = ofproto_dpif_cast(ofproto_);
     const char *name = ofproto->up.name;
@@ -675,9 +675,10 @@ construct(struct ofproto *ofproto_, int *n_tablesp)
 
     hmap_insert(&all_ofproto_dpifs, &ofproto->all_ofproto_dpifs_node,
                 hash_string(ofproto->up.name, 0));
-
-    *n_tablesp = N_TABLES;
     memset(&ofproto->stats, 0, sizeof ofproto->stats);
+
+    ofproto_init_tables(ofproto_, N_TABLES);
+
     return 0;
 }
 
diff --git a/ofproto/ofproto-provider.h b/ofproto/ofproto-provider.h
index 164e88a..0c514c6 100644
--- a/ofproto/ofproto-provider.h
+++ b/ofproto/ofproto-provider.h
@@ -80,6 +80,8 @@ struct ofproto {
     bool vlans_changed;             /* True if new VLANs are in use. */
 };
 
+void ofproto_init_tables(struct ofproto *, int n_tables);
+
 struct ofproto *ofproto_lookup(const char *name);
 struct ofport *ofproto_get_port(const struct ofproto *, uint16_t ofp_port);
 
@@ -294,14 +296,11 @@ struct ofproto_class {
      *
      * When ->construct() is called, the client does not yet know how many flow
      * tables the datapath supports, so ofproto->n_tables will be 0 and
-     * ofproto->tables will be NULL.  ->construct() should store the number of
-     * flow tables supported by the datapath (between 1 and 255, inclusive)
-     * into '*n_tables'.  After a successful return, the client will initialize
-     * the base 'n_tables' member to '*n_tables' and allocate and initialize
-     * the base 'tables' member as the specified number of empty flow tables.
-     * Each flow table will be initially empty, so ->construct() should delete
-     * flows from the underlying datapath, if necessary, rather than populating
-     * the tables.
+     * ofproto->tables will be NULL.  ->construct() should call
+     * ofproto_init_tables() to allocate and initialize ofproto->n_tables and
+     * ofproto->tables.  Each flow table will be initially empty, so
+     * ->construct() should delete flows from the underlying datapath, if
+     * necessary, rather than populating the tables.
      *
      * Only one ofproto instance needs to be supported for any given datapath.
      * If a datapath is already open as part of one "ofproto", then another
@@ -324,7 +323,7 @@ struct ofproto_class {
      * returns.
      */
     struct ofproto *(*alloc)(void);
-    int (*construct)(struct ofproto *ofproto, int *n_tables);
+    int (*construct)(struct ofproto *ofproto);
     void (*destruct)(struct ofproto *ofproto);
     void (*dealloc)(struct ofproto *ofproto);
 
diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index ceec11f..f589a4a 100644
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -287,8 +287,6 @@ ofproto_create(const char *datapath_name, const char *datapath_type,
 {
     const struct ofproto_class *class;
     struct ofproto *ofproto;
-    struct oftable *table;
-    int n_tables;
     int error;
 
     *ofprotop = NULL;
@@ -341,7 +339,7 @@ ofproto_create(const char *datapath_name, const char *datapath_type,
     ofproto->vlan_bitmap = NULL;
     ofproto->vlans_changed = false;
 
-    error = ofproto->ofproto_class->construct(ofproto, &n_tables);
+    error = ofproto->ofproto_class->construct(ofproto);
     if (error) {
         VLOG_ERR("failed to open datapath %s: %s",
                  datapath_name, strerror(error));
@@ -349,12 +347,7 @@ ofproto_create(const char *datapath_name, const char *datapath_type,
         return error;
     }
 
-    assert(n_tables >= 1 && n_tables <= 255);
-    ofproto->n_tables = n_tables;
-    ofproto->tables = xmalloc(n_tables * sizeof *ofproto->tables);
-    OFPROTO_FOR_EACH_TABLE (table, ofproto) {
-        classifier_init(&table->cls);
-    }
+    assert(ofproto->n_tables);
 
     ofproto->datapath_id = pick_datapath_id(ofproto);
     VLOG_INFO("using datapath ID %016"PRIx64, ofproto->datapath_id);
@@ -365,6 +358,21 @@ ofproto_create(const char *datapath_name, const char *datapath_type,
 }
 
 void
+ofproto_init_tables(struct ofproto *ofproto, int n_tables)
+{
+    struct oftable *table;
+
+    assert(!ofproto->n_tables);
+    assert(n_tables >= 1 && n_tables <= 255);
+
+    ofproto->n_tables = n_tables;
+    ofproto->tables = xmalloc(n_tables * sizeof *ofproto->tables);
+    OFPROTO_FOR_EACH_TABLE (table, ofproto) {
+        classifier_init(&table->cls);
+    }
+}
+
+void
 ofproto_set_datapath_id(struct ofproto *p, uint64_t datapath_id)
 {
     uint64_t old_dpid = p->datapath_id;
-- 
1.7.2.5