1 /* Copyright (c) 2011, 2012 Nicira, Inc.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
26 /* Abstract representation of an OVSDB client connection, not tied to any
27 * particular network protocol. Protocol implementations
28 * (e.g. jsonrpc-server.c) embed this in a larger data structure. */
29 struct ovsdb_session {
30 struct ovsdb_server *server;
31 struct list completions; /* Completed triggers. */
32 struct hmap waiters; /* "ovsdb_lock_waiter *"s by lock name. */
35 void ovsdb_session_init(struct ovsdb_session *, struct ovsdb_server *);
36 void ovsdb_session_destroy(struct ovsdb_session *);
38 struct ovsdb_lock_waiter *ovsdb_session_get_lock_waiter(
39 const struct ovsdb_session *, const char *lock_name);
43 * A lock always has one or more "lock waiters" kept on a list. The waiter at
44 * the head of the list owns the lock. */
46 struct hmap_node hmap_node; /* In ovsdb_server's "locks" hmap. */
47 struct ovsdb_server *server; /* The containing server. */
48 char *name; /* Unique name. */
49 struct list waiters; /* Contains "struct ovsdb_lock_waiter"s. */
52 struct ovsdb_lock_waiter *ovsdb_lock_get_owner(const struct ovsdb_lock *);
54 /* How to obtain a lock. */
55 enum ovsdb_lock_mode {
56 OVSDB_LOCK_WAIT, /* By waiting for it to become available. */
57 OVSDB_LOCK_STEAL /* By stealing it from the owner. */
60 /* A session's request for a database lock. */
61 struct ovsdb_lock_waiter {
62 struct hmap_node session_node; /* In ->session->locks's hmap. */
63 struct ovsdb_lock *lock; /* The lock being waited for. */
65 enum ovsdb_lock_mode mode;
68 struct ovsdb_session *session;
69 struct list lock_node; /* In ->lock->waiters's list. */
72 struct ovsdb_session *ovsdb_lock_waiter_remove(struct ovsdb_lock_waiter *);
73 void ovsdb_lock_waiter_destroy(struct ovsdb_lock_waiter *);
74 bool ovsdb_lock_waiter_is_owner(const struct ovsdb_lock_waiter *);
76 /* Abstract representation of an OVSDB server not tied to any particular
77 * network protocol. Protocol implementations (e.g. jsonrpc-server.c) embed
78 * this in a larger data structure. */
80 struct shash dbs; /* Maps from a db name to a "struct ovsdb *". */
81 struct hmap locks; /* Contains "struct ovsdb_lock"s indexed by name. */
84 void ovsdb_server_init(struct ovsdb_server *);
85 bool ovsdb_server_add_db(struct ovsdb_server *, struct ovsdb *);
86 bool ovsdb_server_remove_db(struct ovsdb_server *, struct ovsdb *);
87 void ovsdb_server_destroy(struct ovsdb_server *);
89 struct ovsdb_lock_waiter *ovsdb_server_lock(struct ovsdb_server *,
90 struct ovsdb_session *,
91 const char *lock_name,
93 struct ovsdb_session **victimp);
95 #endif /* ovsdb/server.h */