2 * Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 * Opaque type for the Async. Logging Queue
37 /* The thread for the logging daemon */
38 extern struct thread *ald_thread;
41 * Async. Logging Entry
44 struct ale *ae_next; /* Next Entry */
45 char *ae_data; /* Entry buffer */
46 int ae_flags; /* Entry flags */
49 #define AE_VALID 0x0001 /* Entry has valid data */
53 #define ALQ_NOWAIT 0x0001
54 #define ALQ_WAITOK 0x0002
56 /* Suggested mode for file creation. */
57 #define ALQ_DEFAULT_CMODE 0600
60 * alq_open: Creates a new queue
63 * alq Storage for a pointer to the newly created queue.
64 * file The filename to open for logging.
65 * cred Credential to authorize open and I/O with.
66 * cmode Creation mode for file, if new.
67 * size The size of each entry in the queue.
68 * count The number of items in the buffer, this should be large enough
69 * to store items over the period of a disk write.
71 * error from open or 0 on success
74 int alq_open(struct alq **, const char *file, struct ucred *cred, int cmode,
78 * alq_write: Write data into the queue
81 * alq The queue we're writing to
82 * data The entry to be recorded
83 * waitok Are we permitted to wait?
87 * Waitok is ALQ_NOWAIT and the queue is full.
88 * The system is shutting down.
91 int alq_write(struct alq *alq, void *data, int waitok);
94 * alq_flush: Flush the queue out to disk
96 void alq_flush(struct alq *alq);
99 * alq_close: Flush the queue and free all resources.
101 void alq_close(struct alq *alq);
104 * alq_get: Return an entry for direct access
107 * alq The queue to retrieve an entry from
108 * waitok Are we permitted to wait?
111 * The next available ale on success.
113 * Waitok is ALQ_NOWAIT and the queue is full.
114 * The system is shutting down.
116 * This leaves the queue locked until a subsequent alq_post.
118 struct ale *alq_get(struct alq *alq, int waitok);
121 * alq_post: Schedule the ale retrieved by alq_get for writing.
122 * alq The queue to post the entry to.
123 * ale An asynch logging entry returned by alq_get.
125 void alq_post(struct alq *, struct ale *);
127 #endif /* _SYS_ALQ_H_ */