void init_queue(queue_t *q, int num_threads)
{
int i, j;
+ for (i = 0; i < MAX_NODES; i++) {
+ atomic_init(&q->nodes[i].next, MAKE_POINTER(POISON_IDX, 0));
+ }
/* Initialize each thread's free list with INITIAL_FREE pointers */
/* The actual nodes are initialized with poison indexes */
atomic_store_explicit(&q->nodes[node].next, tmp, relaxed);
while (!success) {
+
/**
@Begin
@Commit_point_clear: true
*/
/**** detected UL ****/
tail = atomic_load_explicit(&q->tail, acquire);
- /**
- @Begin
- @Commit_point_define_check: true
- @Label: Enqueue_Read_Tail
- @End
- */
/****FIXME: miss ****/
next = atomic_load_explicit(&q->nodes[get_ptr(tail)].next, acquire);
//printf("miss1_enqueue\n");
/**
@Begin
@Commit_point_define_check: success
- @Label: Enqueue_UpdateNext
+ @Label: EnqueueUpdateNext
@End
*/
}
&tail,
MAKE_POINTER(node, get_count(tail) + 1),
release, relaxed);
- /**
- //@Begin
- @Commit_point_define_check: succ
- @Label: Enqueue_UpdateOrLoad_Tail
- @End
- */
}
/**
*/
bool dequeue(queue_t *q, int *retVal)
{
- unsigned int value;
+ unsigned int value = 0;
int success = 0;
pointer head;
pointer tail;
*/
/**** detected correctness error ****/
head = atomic_load_explicit(&q->head, acquire);
- /**
- @Begin
- @Commit_point_define_check: true
- @Label: Dequeue_Read_Head
- @End
- */
+ /** A new bug has been found here!!! It should be acquire instead of
+ * relaxed (it introduces a bug when there's two dequeuers and one
+ * enqueuer) correctness bug!!
+ */
tail = atomic_load_explicit(&q->tail, acquire);
- /**
- @Begin
- @Potential_commit_point_define: true
- @Label: Dequeue_Potential_Read_Tail
- @End
- */
- /****FIXME: miss ****/
+ /**** Detected UL/DR (testcase1.c) ****/
next = atomic_load_explicit(&q->nodes[get_ptr(head)].next, acquire);
/**
@Begin
- @Potential_commit_point_define: true
- @Label: Dequeue_Potential_LoadNext
+ @Potential_commit_point_define: true
+ @Label: DequeueReadNext
@End
*/
-
if (atomic_load_explicit(&q->head, relaxed) == head) {
if (get_ptr(head) == get_ptr(tail)) {
/* Check for uninitialized 'next' */
//MODEL_ASSERT(get_ptr(next) != POISON_IDX);
- if (get_ptr(next) == 0) { // NULL
- /**
- @Begin
- @Commit_point_define: true
- @Potential_commit_point_label: Dequeue_Potential_Read_Tail
- @Label: Dequeue_Read_Tail
- @End
- */
+ if (get_ptr(next) == 0) { // NULL
return false; // NULL
}
- /****FIXME: miss (not reached) ****/
+ /**** Detected UL (testcase1.c) ****/
// Second release can be just relaxed
bool succ = false;
succ = atomic_compare_exchange_strong_explicit(&q->tail,
//printf("miss4_dequeue\n");
thrd_yield();
} else {
- /**
- @Begin
- @Commit_point_define: true
- @Potential_commit_point_label: Dequeue_Potential_LoadNext
- @Label: Dequeue_LoadNext
- @End
- */
value = load_32(&q->nodes[get_ptr(next)].value);
- *retVal = value;
//value = q->nodes[get_ptr(next)].value;
- /****FIXME: correctness error ****/
+ /**** correctness error ****/
success = atomic_compare_exchange_strong_explicit(&q->head,
&head,
MAKE_POINTER(get_ptr(next), get_count(head) + 1),
release, relaxed);
+ /**
+ @Begin
+ @Commit_point_define_check: success
+ @Label: DequeueUpdateHead
+ @End
+ */
+
+ /**
+ @Begin
+ @Commit_point_define: success
+ @Potential_commit_point_label: DequeueReadNext
+ @Label: DequeueReadNextVerify
+ @End
+ */
if (!success)
thrd_yield();
}
}
}
reclaim(get_ptr(head));
+ *retVal = value;
return true;
}