*/
int take(Deque *q) {
size_t b = atomic_load_explicit(&q->bottom, memory_order_relaxed) - 1;
+ /**
+ @Begin
+ @Commit_point_define_check: true
+ @Label: Take_Read_Bottom
+ @End
+ */
Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
+ /**
+ //@Begin
+ @Commit_point_define_check: true
+ @Label: Take_Read_Array
+ @End
+ */
atomic_store_explicit(&q->bottom, b, memory_order_relaxed);
+ /**** SPEC (sequential) (testcase1.c) ****/
atomic_thread_fence(memory_order_seq_cst);
size_t t = atomic_load_explicit(&q->top, memory_order_relaxed);
/**
- @Begin
- @Commit_point_define_check: t > b
- @Label: Take_Point_1
+ //@Begin
+ @Commit_point_define_check: t != b
+ @Label: Take_Read_Top
@End
*/
int x;
if (t <= b) {
/* Non-empty queue. */
- x = atomic_load_explicit(&a->buffer[b % atomic_load_explicit(&a->size,memory_order_relaxed)], memory_order_relaxed);
+ int size = atomic_load_explicit(&a->size,memory_order_relaxed);
+ x = atomic_load_explicit(&a->buffer[b % size], memory_order_relaxed);
/**
- @Begin
+ //@Begin
@Commit_point_define_check: t != b
- @Label: Take_Point2
+ @Label: Take_Read_Buffer
@End
*/
if (t == b) {
/* Single last element in queue. */
+ //FIXME: weaken the following seq_cst causes no spec problem
bool succ = atomic_compare_exchange_strong_explicit(&q->top, &t, t +
1, memory_order_seq_cst, memory_order_relaxed);
/**
- @Begin
- @Commit_point_define_check: succ == true
- @Label: Take_Point3
+ //@Begin
+ @Commit_point_define_check: succ
+ @Label: Take_CAS_Top
@End
*/
-
+
/**
@Begin
- @Commit_point_define_check: succ == false
- @Label: Take_Point4
+ @Additional_ordering_point_define_check: true
+ @Label: Take_Additional_Point
@End
*/
if (!succ) {
for(i=top; i < bottom; i++) {
atomic_store_explicit(&new_a->buffer[i % new_size], atomic_load_explicit(&a->buffer[i % size], memory_order_relaxed), memory_order_relaxed);
}
+ /**** detected UL ****/
atomic_store_explicit(&q->array, new_a, memory_order_release);
- printf("resize\n");
+ //printf("resize\n");
}
/**
*/
void push(Deque *q, int x) {
size_t b = atomic_load_explicit(&q->bottom, memory_order_relaxed);
+ /**** SPEC (sequential) ****/
size_t t = atomic_load_explicit(&q->top, memory_order_acquire);
Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
if (b - t > atomic_load_explicit(&a->size, memory_order_relaxed) - 1) /* Full queue. */ {
resize(q);
+ // CDSSpec can actually detect the same bug if we avoid the UL error
//Bug in paper...should have next line...
a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
+ /**
+ //@Begin
+ @Commit_point_define_check: true
+ @Label: Push_Read_Array
+ @End
+ */
}
- atomic_store_explicit(&a->buffer[b % atomic_load_explicit(&a->size, memory_order_relaxed)], x, memory_order_relaxed);
+ int size = atomic_load_explicit(&a->size, memory_order_relaxed);
+
+ atomic_store_explicit(&a->buffer[b % size], x, memory_order_relaxed);
+ /**
+ //@Begin
+ @Commit_point_define_check: true
+ @Label: Push_Update_Buffer
+ @End
+ */
+ /**** SPEC (Sync) (run with -u100 to avoid the uninitialized bug) ****/
atomic_thread_fence(memory_order_release);
+ // Watch out!!! We need to specifiy the fence as the commit point because
+ // the synchronization in C11 actually is established at the fence.
/**
@Begin
@Commit_point_define_check: true
- @Label: Push_Point
+ @Label: Push_Update_Bottom
@End
*/
atomic_store_explicit(&q->bottom, b + 1, memory_order_relaxed);
+
}
/**
@End
*/
int steal(Deque *q) {
+ //Watch out: actually on need to be an acquire (don't count it)
+ // An old bug
size_t t = atomic_load_explicit(&q->top, memory_order_acquire);
+ /**
+ //@Begin
+ @Potential_commit_point_define: true
+ @Label: Steal_Potential_Read_Tail
+ @End
+ */
+ //FIXME: remove the fence causes no error and fewer executions..
atomic_thread_fence(memory_order_seq_cst);
+ /**** SPEC & UL ****/
size_t b = atomic_load_explicit(&q->bottom, memory_order_acquire);
/**
@Begin
- @Commit_point_define_check: t >= b
- @Label: Steal_Point1
+ @Commit_point_define_check: true
+ @Label: Steal_Read_Bottom
+ @End
+ */
+
+ /**
+ //@Begin
+ @Commit_point_define: t >= b
+ @Potential_commit_point_label: Steal_Potential_Read_Tail
+ @Label: Steal_Read_Tail
@End
*/
int x = EMPTY;
if (t < b) {
/* Non-empty queue. */
+ /**** detected UL ****/
Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_acquire);
- x = atomic_load_explicit(&a->buffer[t % atomic_load_explicit(&a->size, memory_order_relaxed)], memory_order_relaxed);
+ /**
+ //@Begin
+ @Commit_point_define_check: true
+ @Label: Steal_Read_Array
+ @End
+ */
+ int size = atomic_load_explicit(&a->size, memory_order_relaxed);
+ x = atomic_load_explicit(&a->buffer[t % size], memory_order_relaxed);
+ /**
+ //@Begin
+ @Potential_commit_point_define: true
+ @Label: Steal_Potential_Read_Buffer
+ @End
+ */
+ /**** SPEC (sequential) ****/
bool succ = atomic_compare_exchange_strong_explicit(&q->top, &t, t + 1,
memory_order_seq_cst, memory_order_relaxed);
/**
- @Begin
- @Commit_point_define_check: succ == true
- @Label: Steal_Point2
+ //@Begin
+ @Commit_point_define_check: succ
+ @Label: Steal_CAS_Top
@End
*/
-
+
/**
@Begin
- @Commit_point_define_check: succ == false
- @Label: Steal_Point3
+ @Additional_ordering_point_define_check: true
+ @Label: Steal_Additional_Point
+ @End
+ */
+
+ /**
+ //@Begin
+ @Commit_point_define: succ
+ @Potential_commit_point_label: Steal_Potential_Read_Buffer
+ @Label: Steal_Read_Buffer
@End
*/
if (!succ) {
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