#define acquire memory_order_acquire
#define MAX_FREELIST 4 /* Each thread can own up to MAX_FREELIST free nodes */
-#define INITIAL_FREE 2 /* Each thread starts with INITIAL_FREE free nodes */
+#define INITIAL_FREE 3 /* Each thread starts with INITIAL_FREE free nodes */
#define POISON_IDX 0x666
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) {
- //store_32(&free_lists[t][i], node);
- free_lists[t][i] = node;
+ store_32(&free_lists[t][i], node);
+ //free_lists[t][i] = node;
return;
}
}
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) {
- /****FIXME: detected UL ****/
+ /**
+ @Begin
+ @Commit_point_clear: true
+ @Label: Enqueue_Clear
+ @End
+ */
+ /**** 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");
if (tail == atomic_load_explicit(&q->tail, relaxed)) {
/* Check for uninitialized 'next' */
if (get_ptr(next) == 0) { // == NULL
pointer value = MAKE_POINTER(node, get_count(next) + 1);
- /****FIXME: first release UL, second release miss ****/
+ /**** detected UL ****/
+ // Second release can be just relaxed
success = atomic_compare_exchange_strong_explicit(&q->nodes[get_ptr(tail)].next,
- &next, value, release, release);
+ &next, value, release, relaxed);
/**
@Begin
- @Commit_point_define_check: success == true
- @Label: Enqueue_Success_Point
+ @Commit_point_define_check: success
+ @Label: Enqueue_UpdateNext
@End
*/
}
if (!success) {
- /****FIXME: detected UL ****/
+ // This routine helps the other enqueue to update the tail
+ /**** detected UL ****/
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: both miss ****/
- atomic_compare_exchange_strong_explicit(&q->tail,
- &tail, value, release, release);
+ /****FIXME: miss ****/
+ // Second release can be just relaxed
+ bool succ = false;
+ succ = atomic_compare_exchange_strong_explicit(&q->tail,
+ &tail, value, release, relaxed);
+ if (succ) {
+ //printf("miss2_enqueue CAS succ\n");
+ }
+ //printf("miss2_enqueue\n");
thrd_yield();
}
}
}
- /****FIXME: first UL, second miss ****/
- atomic_compare_exchange_strong_explicit(&q->tail,
+ /**** dectected UL ****/
+ // Second release can be just relaxed
+ bool succ = atomic_compare_exchange_strong_explicit(&q->tail,
&tail,
MAKE_POINTER(node, get_count(tail) + 1),
- release, release);
+ release, relaxed);
+ /**
+ @Begin
+ @Commit_point_define_check: succ
+ @Label: Enqueue_UpdateOrLoad_Tail
+ @End
+ */
}
/**
@Interface_define: Dequeue
@End
*/
-unsigned int dequeue(queue_t *q)
+bool dequeue(queue_t *q, int *output)
{
unsigned int value;
int success = 0;
pointer next;
while (!success) {
- /****FIXME: detected correctness error ****/
+ /**
+ @Begin
+ @Commit_point_clear: true
+ @Label: Dequeue_Clear
+ @End
+ */
+ /**** detected correctness error ****/
head = atomic_load_explicit(&q->head, acquire);
+ /**
+ @Begin
+ @Commit_point_define_check: true
+ @Label: Dequeue_Read_Head
+ @End
+ */
tail = atomic_load_explicit(&q->tail, relaxed);
+ /**
+ @Begin
+ @Potential_commit_point_define: true
+ @Label: Dequeue_Potential_Read_Tail
+ @End
+ */
+
/****FIXME: miss ****/
next = atomic_load_explicit(&q->nodes[get_ptr(head)].next, acquire);
+ /**
+ @Begin
+ @Potential_commit_point_define: true
+ @Label: Dequeue_Potential_LoadNext
+ @End
+ */
+
if (atomic_load_explicit(&q->head, relaxed) == head) {
if (get_ptr(head) == get_ptr(tail)) {
if (get_ptr(next) == 0) { // NULL
/**
@Begin
- @Commit_point_define_check: true
- @Label: Dequeue_Empty_Point
+ @Commit_point_define: true
+ @Potential_commit_point_label: Dequeue_Potential_Read_Tail
+ @Label: Dequeue_Read_Tail
@End
*/
- return 0; // NULL
+ return false; // NULL
}
- /****FIXME: both miss ****/
- atomic_compare_exchange_strong_explicit(&q->tail,
+ /****FIXME: miss (not reached) ****/
+ // 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, release);
+ release, relaxed);
+ if (succ) {
+ //printf("miss4_dequeue CAS succ\n");
+ }
+ //printf("miss4_dequeue\n");
thrd_yield();
} else {
- //value = load_32(&q->nodes[get_ptr(next)].value);
- value = q->nodes[get_ptr(next)].value;
- /****FIXME: first correctness error, second miss ****/
- success = atomic_compare_exchange_strong_explicit(&q->head,
- &head,
- MAKE_POINTER(get_ptr(next), get_count(head) + 1),
- release, release);
/**
@Begin
- @Commit_point_define_check: success == true
- @Label: Dequeue_Success_Point
+ @Commit_point_define: true
+ @Potential_commit_point_label: Dequeue_Potential_LoadNext
+ @Label: Dequeue_LoadNext
@End
*/
+ value = load_32(&q->nodes[get_ptr(next)].value);
+ //value = q->nodes[get_ptr(next)].value;
+ /****FIXME: correctness error ****/
+ success = atomic_compare_exchange_strong_explicit(&q->head,
+ &head,
+ MAKE_POINTER(get_ptr(next), get_count(head) + 1),
+ release, relaxed);
if (!success)
thrd_yield();
}
}
}
reclaim(get_ptr(head));
- return value;
+ *output = value;
+ return true;
}
projects / cdsspec-compiler.git / blobdiff