Line data Source code
1 : /*
2 : * Quagga Work Queues.
3 : *
4 : * Copyright (C) 2005 Sun Microsystems, Inc.
5 : *
6 : * This file is part of Quagga.
7 : *
8 : * Quagga is free software; you can redistribute it and/or modify it
9 : * under the terms of the GNU General Public License as published by the
10 : * Free Software Foundation; either version 2, or (at your option) any
11 : * later version.
12 : *
13 : * Quagga is distributed in the hope that it will be useful, but
14 : * WITHOUT ANY WARRANTY; without even the implied warranty of
15 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 : * General Public License for more details.
17 : *
18 : * You should have received a copy of the GNU General Public License along
19 : * with this program; see the file COPYING; if not, write to the Free Software
20 : * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 : */
22 :
23 : #ifndef _QUAGGA_WORK_QUEUE_H
24 : #define _QUAGGA_WORK_QUEUE_H
25 :
26 : #include "memory.h"
27 : #include "queue.h"
28 :
29 : #ifdef __cplusplus
30 : extern "C" {
31 : #endif
32 :
33 : DECLARE_MTYPE(WORK_QUEUE);
34 :
35 : /* Hold time for the initial schedule of a queue run, in millisec */
36 : #define WORK_QUEUE_DEFAULT_HOLD 50
37 :
38 : /* Retry for queue that is 'blocked' or 'retry later' */
39 : #define WORK_QUEUE_DEFAULT_RETRY 0
40 :
41 : /* action value, for use by item processor and item error handlers */
42 : typedef enum {
43 : WQ_SUCCESS = 0,
44 : WQ_RETRY_NOW, /* retry immediately */
45 : WQ_RETRY_LATER, /* retry later, cease processing work queue */
46 : WQ_REQUEUE, /* requeue item, continue processing work queue */
47 : WQ_QUEUE_BLOCKED, /* Queue cant be processed at this time.
48 : * Similar to WQ_RETRY_LATER, but doesn't penalise
49 : * the particular item.. */
50 : } wq_item_status;
51 :
52 : /* A single work queue item, unsurprisingly */
53 : struct work_queue_item {
54 : STAILQ_ENTRY(work_queue_item) wq;
55 : void *data; /* opaque data */
56 : unsigned short ran; /* # of times item has been run */
57 : };
58 :
59 : #define WQ_UNPLUGGED (1 << 0) /* available for draining */
60 :
61 : struct work_queue {
62 : /* Everything but the specification struct is private
63 : * the following may be read
64 : */
65 : struct thread_master *master; /* thread master */
66 : struct thread *thread; /* thread, if one is active */
67 : char *name; /* work queue name */
68 :
69 : /* Specification for this work queue.
70 : * Public, must be set before use by caller. May be modified at will.
71 : */
72 : struct {
73 : /* optional opaque user data, global to the queue. */
74 : void *data;
75 :
76 : /* work function to process items with:
77 : * First argument is the workqueue queue.
78 : * Second argument is the item data
79 : */
80 : wq_item_status (*workfunc)(struct work_queue *, void *);
81 :
82 : /* callback to delete user specific item data */
83 : void (*del_item_data)(struct work_queue *, void *);
84 :
85 : /* completion callback, called when queue is emptied, optional
86 : */
87 : void (*completion_func)(struct work_queue *);
88 :
89 : /* max number of retries to make for item that errors */
90 : unsigned int max_retries;
91 :
92 : unsigned int hold; /* hold time for first run, in ms */
93 :
94 : unsigned long
95 : yield; /* yield time in us for associated thread */
96 :
97 : uint32_t retry; /* Optional retry timeout if queue is blocked */
98 : } spec;
99 :
100 : /* remaining fields should be opaque to users */
101 : STAILQ_HEAD(work_queue_items, work_queue_item)
102 : items; /* queue item list */
103 : int item_count; /* queued items */
104 : unsigned long runs; /* runs count */
105 : unsigned long yields; /* yields count */
106 :
107 : struct {
108 : unsigned int best;
109 : unsigned int granularity;
110 : unsigned long total;
111 : } cycles; /* cycle counts */
112 :
113 : /* private state */
114 : uint16_t flags; /* user set flag */
115 : };
116 :
117 : /* User API */
118 :
119 0 : static inline int work_queue_item_count(struct work_queue *wq)
120 : {
121 0 : return wq->item_count;
122 : }
123 :
124 79 : static inline bool work_queue_empty(struct work_queue *wq)
125 : {
126 79 : return (wq->item_count == 0) ? true : false;
127 : }
128 :
129 : static inline struct work_queue_item *
130 0 : work_queue_last_item(struct work_queue *wq)
131 : {
132 0 : return STAILQ_LAST(&wq->items, work_queue_item, wq);
133 : }
134 :
135 68 : static inline void work_queue_item_enqueue(struct work_queue *wq,
136 : struct work_queue_item *item)
137 : {
138 68 : STAILQ_INSERT_TAIL(&wq->items, item, wq);
139 5 : wq->item_count++;
140 : }
141 :
142 68 : static inline void work_queue_item_dequeue(struct work_queue *wq,
143 : struct work_queue_item *item)
144 : {
145 68 : assert(wq->item_count > 0);
146 :
147 68 : wq->item_count--;
148 68 : STAILQ_REMOVE(&wq->items, item, work_queue_item, wq);
149 68 : }
150 :
151 : /* create a new work queue, of given name.
152 : * user must fill in the spec of the returned work queue before adding
153 : * anything to it
154 : */
155 : extern struct work_queue *work_queue_new(struct thread_master *m,
156 : const char *queue_name);
157 :
158 : /* destroy work queue */
159 : /*
160 : * The usage of work_queue_free is being transitioned to pass
161 : * in the double pointer to remove use after free's.
162 : */
163 : extern void work_queue_free_and_null(struct work_queue **wqp);
164 :
165 : /* Add the supplied data as an item onto the workqueue */
166 : extern void work_queue_add(struct work_queue *wq, void *item);
167 :
168 : /* plug the queue, ie prevent it from being drained / processed */
169 : extern void work_queue_plug(struct work_queue *wq);
170 : /* unplug the queue, allow it to be drained again */
171 : extern void work_queue_unplug(struct work_queue *wq);
172 :
173 : bool work_queue_is_scheduled(struct work_queue *wq);
174 :
175 : /* Helpers, exported for thread.c and command.c */
176 : extern void work_queue_run(struct thread *thread);
177 :
178 : extern void workqueue_cmd_init(void);
179 :
180 : #ifdef __cplusplus
181 : }
182 : #endif
183 :
184 : #endif /* _QUAGGA_WORK_QUEUE_H */
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