Skip to content
Permalink
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
84 lines (70 sloc) 1.59 KB
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include "queue.h"
#define QUEUE_POISON1 ((void*)0xCAFEBAB5)
struct queue_root {
struct queue_head *in_queue;
struct queue_head *out_queue;
// pthread_spinlock_t lock;
pthread_mutex_t lock;
};
#ifndef _cas
# define _cas(ptr, oldval, newval) \
__sync_bool_compare_and_swap(ptr, oldval, newval)
#endif
struct queue_root *ALLOC_QUEUE_ROOT()
{
struct queue_root *root = \
malloc(sizeof(struct queue_root));
// pthread_spin_init(&root->lock, PTHREAD_PROCESS_PRIVATE);
pthread_mutex_init(&root->lock, NULL);
root->in_queue = NULL;
root->out_queue = NULL;
return root;
}
void INIT_QUEUE_HEAD(struct queue_head *head)
{
head->next = QUEUE_POISON1;
}
void queue_put(struct queue_head *new,
struct queue_root *root)
{
while (1) {
struct queue_head *in_queue = root->in_queue;
new->next = in_queue;
if (_cas(&root->in_queue, in_queue, new)) {
break;
}
}
}
struct queue_head *queue_get(struct queue_root *root)
{
// pthread_spin_lock(&root->lock);
pthread_mutex_lock(&root->lock);
if (!root->out_queue) {
while (1) {
struct queue_head *head = root->in_queue;
if (!head) {
break;
}
if (_cas(&root->in_queue, head, NULL)) {
// Reverse the order
while (head) {
struct queue_head *next = head->next;
head->next = root->out_queue;
root->out_queue = head;
head = next;
}
break;
}
}
}
struct queue_head *head = root->out_queue;
if (head) {
root->out_queue = head->next;
}
// pthread_spin_unlock(&root->lock);
pthread_mutex_unlock(&root->lock);
return head;
}
You can’t perform that action at this time.