blob: 31a2d14225d690e7f80b4c3e385d0a0698a5b3d7 [file] [log] [blame]
Matthew Wilcox1366c372016-03-17 14:21:45 -07001#include <linux/rcupdate.h>
2#include <pthread.h>
3#include <stdio.h>
4#include <assert.h>
5
6static pthread_mutex_t rculock = PTHREAD_MUTEX_INITIALIZER;
7static struct rcu_head *rcuhead_global = NULL;
8static __thread int nr_rcuhead = 0;
9static __thread struct rcu_head *rcuhead = NULL;
10static __thread struct rcu_head *rcutail = NULL;
11
12static pthread_cond_t rcu_worker_cond = PTHREAD_COND_INITIALIZER;
13
14/* switch to urcu implementation when it is merged. */
15void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *head))
16{
17 head->func = func;
18 head->next = rcuhead;
19 rcuhead = head;
20 if (!rcutail)
21 rcutail = head;
22 nr_rcuhead++;
23 if (nr_rcuhead >= 1000) {
24 int signal = 0;
25
26 pthread_mutex_lock(&rculock);
27 if (!rcuhead_global)
28 signal = 1;
29 rcutail->next = rcuhead_global;
30 rcuhead_global = head;
31 pthread_mutex_unlock(&rculock);
32
33 nr_rcuhead = 0;
34 rcuhead = NULL;
35 rcutail = NULL;
36
37 if (signal) {
38 pthread_cond_signal(&rcu_worker_cond);
39 }
40 }
41}
42
43static void *rcu_worker(void *arg)
44{
45 struct rcu_head *r;
46
47 rcupdate_thread_init();
48
49 while (1) {
50 pthread_mutex_lock(&rculock);
51 while (!rcuhead_global) {
52 pthread_cond_wait(&rcu_worker_cond, &rculock);
53 }
54 r = rcuhead_global;
55 rcuhead_global = NULL;
56
57 pthread_mutex_unlock(&rculock);
58
59 synchronize_rcu();
60
61 while (r) {
62 struct rcu_head *tmp = r->next;
63 r->func(r);
64 r = tmp;
65 }
66 }
67
68 rcupdate_thread_exit();
69
70 return NULL;
71}
72
73static pthread_t worker_thread;
74void rcupdate_init(void)
75{
76 pthread_create(&worker_thread, NULL, rcu_worker, NULL);
77}
78
79void rcupdate_thread_init(void)
80{
81 rcu_register_thread();
82}
83void rcupdate_thread_exit(void)
84{
85 rcu_unregister_thread();
86}