1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
|
/*
* BIRD Library -- Event Processing
*
* (c) 1999 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
/**
* DOC: Events
*
* Events are there to keep track of deferred execution.
* Since BIRD is single-threaded, it requires long lasting tasks to be split to smaller
* parts, so that no module can monopolize the CPU. To split such a task, just create
* an &event resource, point it to the function you want to have called and call ev_schedule()
* to ask the core to run the event when nothing more important requires attention.
*
* You can also define your own event lists (the &event_list structure), enqueue your
* events in them and explicitly ask to run them.
*/
#include "nest/bird.h"
#include "lib/event.h"
event_list global_event_list;
inline void
ev_postpone(event *e)
{
if (e->n.next)
{
rem_node(&e->n);
e->n.next = NULL;
}
}
static void
ev_dump(resource *r)
{
event *e = (event *) r;
debug("(code %p, data %p, %s)\n",
e->hook,
e->data,
e->n.next ? "scheduled" : "inactive");
}
static struct resclass ev_class = {
"Event",
sizeof(event),
(void (*)(resource *)) ev_postpone,
ev_dump
};
/**
* ev_new - create a new event
* @p: resource pool
*
* This function creates a new event resource. To use it,
* you need to fill the structure fields and call ev_schedule().
*/
event *
ev_new(pool *p)
{
event *e = ralloc(p, &ev_class);
return e;
}
/**
* ev_run - run an event
* @e: an event
*
* This function explicitly runs the event @e (calls its hook
* function) and removes it from an event list if it's linked to any.
*
* From the hook function, you can call ev_enqueue() or ev_schedule()
* to re-add the event.
*/
inline void
ev_run(event *e)
{
ev_postpone(e);
e->hook(e->data);
}
/**
* ev_enqueue - enqueue an event
* @l: an event list
* @e: an event
*
* ev_enqueue() stores the event @e to the specified event
* list @l which can be run by calling ev_run_list().
*/
inline void
ev_enqueue(event_list *l, event *e)
{
ev_postpone(e);
add_tail(l, &e->n);
}
/**
* ev_schedule - schedule an event
* @e: an event
*
* This function schedules an event by enqueueing it to a system-wide
* event list which is run by the platform dependent code whenever
* appropriate.
*/
void
ev_schedule(event *e)
{
ev_enqueue(&global_event_list, e);
}
/**
* ev_run_list - run an event list
* @l: an event list
*
* This function calls ev_run() for all events enqueued in the list @l.
*/
int
ev_run_list(event_list *l)
{
node *n;
list tmp_list;
init_list(&tmp_list);
add_tail_list(&tmp_list, l);
init_list(l);
WALK_LIST_FIRST(n, tmp_list)
{
event *e = SKIP_BACK(event, n, n);
ev_run(e);
}
return !EMPTY_LIST(*l);
}
|
