int i;
int t = get_thread_num();
for (i = 0; i < MAX_FREELIST; i++) {
- unsigned int node = load_32(&free_lists[t][i]);
- //unsigned int node = free_lists[t][i];
+ //unsigned int node = load_32(&free_lists[t][i]);
+ unsigned int node = free_lists[t][i];
if (node) {
- store_32(&free_lists[t][i], 0);
- //free_lists[t][i] = 0;
+ //store_32(&free_lists[t][i], 0);
+ free_lists[t][i] = 0;
return node;
}
}
for (i = 0; i < MAX_FREELIST; i++) {
/* Should never race with our own thread here */
- unsigned int idx = load_32(&free_lists[t][i]);
- //unsigned int idx = free_lists[t][i];
+ //unsigned int idx = load_32(&free_lists[t][i]);
+ unsigned int idx = free_lists[t][i];
/* Found empty spot in free list */
if (idx == 0) {
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 */
pointer tmp;
node = new_node();
- store_32(&q->nodes[node].value, val);
- //q->nodes[node].value = val;
+ //store_32(&q->nodes[node].value, val);
+ q->nodes[node].value = val;
tmp = atomic_load_explicit(&q->nodes[node].next, relaxed);
set_ptr(&tmp, 0); // NULL
atomic_store_explicit(&q->nodes[node].next, tmp, relaxed);
while (!success) {
- /**** detected UL ****/
+
+ /**
+ @Begin
+ @Commit_point_clear: true
+ @Label: Enqueue_Clear
+ @End
+ */
+ /**** UL & inadmissible ****/
tail = atomic_load_explicit(&q->tail, acquire);
/****FIXME: miss ****/
next = atomic_load_explicit(&q->nodes[get_ptr(tail)].next, acquire);
if (get_ptr(next) == 0) { // == NULL
pointer value = MAKE_POINTER(node, get_count(next) + 1);
- /**** detected UL ****/
+ /**** SPEC Error (testcase1.c) ****/
// Second release can be just relaxed
success = atomic_compare_exchange_strong_explicit(&q->nodes[get_ptr(tail)].next,
&next, value, release, relaxed);
/**
@Begin
- @Commit_point_define_check: success == true
- @Label: Enqueue_Success_Point
+ @Commit_point_define_check: success
+ @Label: EnqueueUpdateNext
@End
*/
}
if (!success) {
// This routine helps the other enqueue to update the tail
- /**** detected UL ****/
+ /**** UL & Inadmissible ****/
unsigned int ptr = get_ptr(atomic_load_explicit(&q->nodes[get_ptr(tail)].next, acquire));
pointer value = MAKE_POINTER(ptr,
get_count(tail) + 1);
- /****FIXME: miss ****/
+ /**** SPEC (sequential, testcase2.c) ****/
// Second release can be just relaxed
bool succ = false;
succ = atomic_compare_exchange_strong_explicit(&q->tail,
- &tail, value, release, relaxed);
+ &tail, value, relaxed, relaxed);
if (succ) {
//printf("miss2_enqueue CAS succ\n");
}
}
}
}
- /**** dectected UL ****/
+ /**** UL & Inadmissible ****/
// Second release can be just relaxed
- atomic_compare_exchange_strong_explicit(&q->tail,
+ bool succ = atomic_compare_exchange_strong_explicit(&q->tail,
&tail,
MAKE_POINTER(node, get_count(tail) + 1),
release, relaxed);
@Interface_define: Dequeue
@End
*/
-bool dequeue(queue_t *q, unsigned int *retVal)
+bool dequeue(queue_t *q, int *retVal)
{
- unsigned int value;
+ unsigned int value = 0;
int success = 0;
pointer head;
pointer tail;
pointer next;
while (!success) {
- /**** detected correctness error ****/
+ /**
+ @Begin
+ @Commit_point_clear: true
+ @Label: Dequeue_Clear
+ @End
+ */
+ /**** Inadmissible ****/
head = atomic_load_explicit(&q->head, acquire);
- // FIXME: This must be acquire otherwise we have a bug with 1 enqueue &
- // 1 dequeue
- tail = atomic_load_explicit(&q->tail, relaxed);
- /****FIXME: miss ****/
+ /**
+ @Begin
+ @Commit_point_define_check: true
+ @Label: DequeueReadHead
+ @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!!
+ */
+ /**** SPEC (sequential) (testcase1.c) ****/
+ /**** New bug ****/
+ tail = atomic_load_explicit(&q->tail, acquire);
+
+ /**** SPEC Error (testcase1.c) ****/
next = atomic_load_explicit(&q->nodes[get_ptr(head)].next, acquire);
- //printf("miss3_dequeue\n");
+ /**
+ @Begin
+ @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_check: true
- @Label: Dequeue_Empty_Point
- @End
- */
+ if (get_ptr(next) == 0) { // NULL
return false; // NULL
}
- /****FIXME: miss (not reached) ****/
+ /**** SPEC (sequential testcase3.c) ****/
// Second release can be just relaxed
bool succ = false;
succ = atomic_compare_exchange_strong_explicit(&q->tail,
&tail,
MAKE_POINTER(get_ptr(next), get_count(tail) + 1),
- release, relaxed);
+ release, relaxed);
if (succ) {
//printf("miss4_dequeue CAS succ\n");
}
//printf("miss4_dequeue\n");
thrd_yield();
} else {
- *retVal = load_32(&q->nodes[get_ptr(next)].value);
- //value = q->nodes[get_ptr(next)].value;
- /****FIXME: correctness error ****/
- // Seconde release can be just relaxed
+ //value = load_32(&q->nodes[get_ptr(next)].value);
+ value = q->nodes[get_ptr(next)].value;
+ /**** inadmissibility ****/
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 == true
- @Label: Dequeue_Success_Point
+ @Commit_point_define_check: success
+ @Label: DequeueUpdateHead
+ @End
+ */
+
+ /**
+ @Begin
+ @Commit_point_define: success
+ @Potential_commit_point_label: DequeueReadNext
+ @Label: DequeueReadNextVerify
@End
*/
if (!success)
}
}
reclaim(get_ptr(head));
+ *retVal = value;
return true;
}
projects / cdsspec-compiler.git / blobdiff