-/* Copyright (c) 2011 Nicira Networks
+/* Copyright (c) 2011, 2012 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include "hmap.h"
#include "list.h"
+#include "shash.h"
+
+struct ovsdb;
+struct ovsdb_server;
/* Abstract representation of an OVSDB client connection, not tied to any
* particular network protocol. Protocol implementations
* (e.g. jsonrpc-server.c) embed this in a larger data structure. */
struct ovsdb_session {
- struct ovsdb *db;
+ struct ovsdb_server *server;
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_init(struct ovsdb_session *, struct ovsdb_server *);
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 hmap_node hmap_node; /* In ovsdb_server's "locks" hmap. */
+ struct ovsdb_server *server; /* The containing server. */
+ char *name; /* Unique name. */
+ 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 {
+ struct hmap_node session_node; /* In ->session->locks's hmap. */
+ struct ovsdb_lock *lock; /* The lock being waited for. */
+
+ enum ovsdb_lock_mode mode;
+ char *lock_name;
+
+ struct ovsdb_session *session;
+ struct list lock_node; /* In ->lock->waiters's list. */
+};
+
+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 shash dbs; /* Maps from a db name to a "struct ovsdb *". */
+ struct hmap locks; /* Contains "struct ovsdb_lock"s indexed by name. */
};
-void ovsdb_server_init(struct ovsdb_server *, struct ovsdb *);
+void ovsdb_server_init(struct ovsdb_server *);
+bool ovsdb_server_add_db(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 */