spsc-example/queue.h

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