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.
22 /* Abstract representation of an OVSDB client connection, not tied to any
23 * particular network protocol. Protocol implementations
24 * (e.g. jsonrpc-server.c) embed this in a larger data structure. */
25 struct ovsdb_session {
27 struct list completions; /* Completed triggers. */
28 struct hmap waiters; /* "ovsdb_lock_waiter *"s by lock name. */
31 void ovsdb_session_init(struct ovsdb_session *, struct ovsdb *);
32 void ovsdb_session_destroy(struct ovsdb_session *);
34 struct ovsdb_lock_waiter *ovsdb_session_get_lock_waiter(
35 const struct ovsdb_session *, const char *lock_name);
39 * A lock always has one or more "lock waiters" kept on a list. The waiter at
40 * the head of the list owns the lock. */
42 struct hmap_node hmap_node; /* In ovsdb_server's "locks" hmap. */
43 struct ovsdb_server *server; /* The containing server. */
44 char *name; /* Unique name. */
45 struct list waiters; /* Contains "struct ovsdb_lock_waiter"s. */
48 struct ovsdb_lock_waiter *ovsdb_lock_get_owner(const struct ovsdb_lock *);
50 /* How to obtain a lock. */
51 enum ovsdb_lock_mode {
52 OVSDB_LOCK_WAIT, /* By waiting for it to become available. */
53 OVSDB_LOCK_STEAL /* By stealing it from the owner. */
56 /* A session's request for a database lock. */
57 struct ovsdb_lock_waiter {
58 struct hmap_node session_node; /* In ->session->locks's hmap. */
59 struct ovsdb_lock *lock; /* The lock being waited for. */
61 enum ovsdb_lock_mode mode;
64 struct ovsdb_session *session;
65 struct list lock_node; /* In ->lock->waiters's list. */
68 struct ovsdb_session *ovsdb_lock_waiter_remove(struct ovsdb_lock_waiter *);
69 void ovsdb_lock_waiter_destroy(struct ovsdb_lock_waiter *);
70 bool ovsdb_lock_waiter_is_owner(const struct ovsdb_lock_waiter *);
72 /* Abstract representation of an OVSDB server not tied to any particular
73 * network protocol. Protocol implementations (e.g. jsonrpc-server.c) embed
74 * this in a larger data structure. */
77 struct hmap locks; /* Contains "struct ovsdb_lock"s indexed by name. */
80 void ovsdb_server_init(struct ovsdb_server *, struct ovsdb *);
81 void ovsdb_server_destroy(struct ovsdb_server *);
83 struct ovsdb_lock_waiter *ovsdb_server_lock(struct ovsdb_server *,
84 struct ovsdb_session *,
85 const char *lock_name,
87 struct ovsdb_session **victimp);
89 #endif /* ovsdb/server.h */