spsc-example/queue.h

   1 #include <unrelacy.h>
   2 #include <atomic>
   3 #include "wildcard.h"
   4
   5 using namespace std;
   6
   7 struct node {
   8         node(int d) {
   9                 data.store(0, memory_order_normal);
  10                 next.store(0, wildcard(1));
  11         }
  12         atomic<node*> next;
  13         atomic_int data;
  14 };
  15
  16 class spsc_queue
  17 {
  18         atomic<node*> head, tail;
  19         public:
  20         spsc_queue() {
  21                 head = tail = new node(0);
  22         }
  23
  24         void enqueue(int val) {
  25                 node* n = new node(val);
  26                 node *h = head.load(wildcard(2));
  27                 h->next.store(n, wildcard(3));
  28                 head.store(n, wildcard(4));
  29         }
  30
  31         bool dequeue(int *v) {
  32                 node* t = tail.load(wildcard(5));
  33                 node* n = t->next.load(wildcard(6));
  34                 if (0 == n)
  35                         return false;
  36                 *v = n->data.load(memory_order_normal);
  37                 tail.store(n, wildcard(7));
  38                 delete (t);
  39                 return true;
  40         }
  41 };