X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=ovsdb%2Fserver.h;h=a9285f79ee08e6b25be9d6bb0f8ebf2149639b74;hb=da897f41cd795e325ec5ce773a70a819100bd26e;hp=ce19b8d09e431f7593f0c6c9f4336153845ee5a9;hpb=e317253b1391c7b0a84c8dd51eaf1f3cc16eff56;p=sliver-openvswitch.git

diff --git a/ovsdb/server.h b/ovsdb/server.h
index ce19b8d09..a9285f79e 100644
--- a/ovsdb/server.h
+++ b/ovsdb/server.h
@@ -25,19 +25,65 @@
 struct ovsdb_session {
     struct ovsdb *db;
     struct list completions;    /* Completed triggers. */
+    struct hmap waiters;        /* "ovsdb_lock_waiter *"s by lock name. */
 };
 
 void ovsdb_session_init(struct ovsdb_session *, struct ovsdb *);
 void ovsdb_session_destroy(struct ovsdb_session *);
 
+struct ovsdb_lock_waiter *ovsdb_session_get_lock_waiter(
+    const struct ovsdb_session *, const char *lock_name);
+
+/* A database lock.
+ *
+ * A lock always has one or more "lock waiters" kept on a list.  The waiter at
+ * the head of the list owns the lock. */
+struct ovsdb_lock {
+    struct ovsdb_server *server; /* The containing server. */
+    char *name;                  /* Unique name. */
+    struct hmap_node hmap_node;  /* In ovsdb_server's "locks" hmap. */
+    struct list waiters;         /* Contains "struct ovsdb_lock_waiter"s. */
+};
+
+struct ovsdb_lock_waiter *ovsdb_lock_get_owner(const struct ovsdb_lock *);
+
+/* How to obtain a lock. */
+enum ovsdb_lock_mode {
+    OVSDB_LOCK_WAIT,            /* By waiting for it to become available. */
+    OVSDB_LOCK_STEAL            /* By stealing it from the owner. */
+};
+
+/* A session's request for a database lock. */
+struct ovsdb_lock_waiter {
+    enum ovsdb_lock_mode mode;
+    char *lock_name;
+
+    struct ovsdb_lock *lock;    /* The lock being waited for. */
+    struct list lock_node;      /* In ->lock->waiters's list. */
+
+    struct ovsdb_session *session;
+    struct hmap_node session_node; /* In ->session->locks's hmap. */
+};
+
+struct ovsdb_session *ovsdb_lock_waiter_remove(struct ovsdb_lock_waiter *);
+void ovsdb_lock_waiter_destroy(struct ovsdb_lock_waiter *);
+bool ovsdb_lock_waiter_is_owner(const struct ovsdb_lock_waiter *);
+
 /* Abstract representation of an OVSDB server not tied to any particular
  * network protocol.  Protocol implementations (e.g. jsonrpc-server.c) embed
  * this in a larger data structure.  */
 struct ovsdb_server {
     struct ovsdb *db;
+    struct hmap locks;     /* Contains "struct ovsdb_lock"s indexed by name. */
 };
 
 void ovsdb_server_init(struct ovsdb_server *, struct ovsdb *);
 void ovsdb_server_destroy(struct ovsdb_server *);
 
+struct ovsdb_lock_waiter *ovsdb_server_lock(struct ovsdb_server *,
+                                            struct ovsdb_session *,
+                                            const char *lock_name,
+                                            enum ovsdb_lock_mode,
+                                            struct ovsdb_session **victimp);
+
 #endif /* ovsdb/server.h */