rcupdate.c
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#include <linux/rcupdate.h>
#include <pthread.h>
#include <stdio.h>
#include <assert.h>
static pthread_mutex_t rculock = PTHREAD_MUTEX_INITIALIZER;
static struct rcu_head *rcuhead_global = NULL;
static __thread int nr_rcuhead = 0;
static __thread struct rcu_head *rcuhead = NULL;
static __thread struct rcu_head *rcutail = NULL;
static pthread_cond_t rcu_worker_cond = PTHREAD_COND_INITIALIZER;
/* switch to urcu implementation when it is merged. */
void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *head))
{
head->func = func;
head->next = rcuhead;
rcuhead = head;
if (!rcutail)
rcutail = head;
nr_rcuhead++;
if (nr_rcuhead >= 1000) {
int signal = 0;
pthread_mutex_lock(&rculock);
if (!rcuhead_global)
signal = 1;
rcutail->next = rcuhead_global;
rcuhead_global = head;
pthread_mutex_unlock(&rculock);
nr_rcuhead = 0;
rcuhead = NULL;
rcutail = NULL;
if (signal) {
pthread_cond_signal(&rcu_worker_cond);
}
}
}
static void *rcu_worker(void *arg)
{
struct rcu_head *r;
rcupdate_thread_init();
while (1) {
pthread_mutex_lock(&rculock);
while (!rcuhead_global) {
pthread_cond_wait(&rcu_worker_cond, &rculock);
}
r = rcuhead_global;
rcuhead_global = NULL;
pthread_mutex_unlock(&rculock);
synchronize_rcu();
while (r) {
struct rcu_head *tmp = r->next;
r->func(r);
r = tmp;
}
}
rcupdate_thread_exit();
return NULL;
}
static pthread_t worker_thread;
void rcupdate_init(void)
{
pthread_create(&worker_thread, NULL, rcu_worker, NULL);
}
void rcupdate_thread_init(void)
{
rcu_register_thread();
}
void rcupdate_thread_exit(void)
{
rcu_unregister_thread();
}