8 Deque * q = (Deque *) calloc(1, sizeof(Deque));
9 Array * a = (Array *) calloc(1, sizeof(Array)+2*sizeof(atomic_int));
10 atomic_store_explicit(&q->array, a, memory_order_relaxed);
11 atomic_store_explicit(&q->top, 0, memory_order_relaxed);
12 atomic_store_explicit(&q->bottom, 0, memory_order_relaxed);
13 atomic_store_explicit(&a->size, 2, memory_order_relaxed);
20 @Interface_define: Take
24 size_t b = atomic_load_explicit(&q->bottom, memory_order_relaxed) - 1;
27 @Commit_point_define_check: true
28 @Label: Take_Read_Bottom
31 Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
34 @Commit_point_define_check: true
35 @Label: Take_Read_Array
38 atomic_store_explicit(&q->bottom, b, memory_order_relaxed);
39 /**** detected correctness ****/
40 atomic_thread_fence(memory_order_seq_cst);
41 size_t t = atomic_load_explicit(&q->top, memory_order_relaxed);
44 @Commit_point_define_check: t != b
50 /* Non-empty queue. */
51 int size = atomic_load_explicit(&a->size,memory_order_relaxed);
52 x = atomic_load_explicit(&a->buffer[b % size], memory_order_relaxed);
55 @Commit_point_define_check: t != b
56 @Label: Take_Read_Buffer
60 /* Single last element in queue. */
61 //FIXME: weaken the following seq_cst causes no spec problem
62 bool succ = atomic_compare_exchange_strong_explicit(&q->top, &t, t +
63 1, memory_order_seq_cst, memory_order_relaxed);
66 @Commit_point_define_check: succ
73 @Additional_ordering_point_define_check: !succ
74 @Label: Take_Additional_Point
81 atomic_store_explicit(&q->bottom, b + 1, memory_order_relaxed);
83 } else { /* Empty queue. */
85 atomic_store_explicit(&q->bottom, b + 1, memory_order_relaxed);
90 void resize(Deque *q) {
91 Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
92 size_t size=atomic_load_explicit(&a->size, memory_order_relaxed);
93 size_t new_size=size << 1;
94 Array *new_a = (Array *) calloc(1, new_size * sizeof(atomic_int) + sizeof(Array));
95 size_t top=atomic_load_explicit(&q->top, memory_order_relaxed);
96 size_t bottom=atomic_load_explicit(&q->bottom, memory_order_relaxed);
97 atomic_store_explicit(&new_a->size, new_size, memory_order_relaxed);
99 for(i=top; i < bottom; i++) {
100 atomic_store_explicit(&new_a->buffer[i % new_size], atomic_load_explicit(&a->buffer[i % size], memory_order_relaxed), memory_order_relaxed);
102 /**** detected UL ****/
103 atomic_store_explicit(&q->array, new_a, memory_order_release);
104 //printf("resize\n");
109 @Interface_define: Push
112 void push(Deque *q, int x) {
113 size_t b = atomic_load_explicit(&q->bottom, memory_order_relaxed);
114 /**** detected correctness ****/
115 size_t t = atomic_load_explicit(&q->top, memory_order_acquire);
116 Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
117 if (b - t > atomic_load_explicit(&a->size, memory_order_relaxed) - 1) /* Full queue. */ {
119 //Bug in paper...should have next line...
120 a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
123 @Commit_point_define_check: true
124 @Label: Push_Read_Array
128 int size = atomic_load_explicit(&a->size, memory_order_relaxed);
130 atomic_store_explicit(&a->buffer[b % size], x, memory_order_relaxed);
133 @Commit_point_define_check: true
134 @Label: Push_Update_Buffer
137 /**** correctness error ****/
138 atomic_thread_fence(memory_order_release);
140 atomic_store_explicit(&q->bottom, b + 1, memory_order_relaxed);
143 @Commit_point_define_check: true
144 @Label: Push_Update_Bottom
151 @Interface_define: Steal
154 int steal(Deque *q) {
155 //FIXME: weaken the following acquire causes no spec problem
156 size_t t = atomic_load_explicit(&q->top, memory_order_acquire);
159 @Potential_commit_point_define: true
160 @Label: Steal_Potential_Read_Tail
163 //FIXME: remove the fence causes no error and fewer executions..
164 atomic_thread_fence(memory_order_seq_cst);
165 /**** detected UL ****/
166 size_t b = atomic_load_explicit(&q->bottom, memory_order_acquire);
169 @Commit_point_define_check: true
170 @Label: Steal_Read_Bottom
176 @Commit_point_define: t >= b
177 @Potential_commit_point_label: Steal_Potential_Read_Tail
178 @Label: Steal_Read_Tail
183 /* Non-empty queue. */
184 /**** detected UL ****/
185 Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_acquire);
188 @Commit_point_define_check: true
189 @Label: Steal_Read_Array
192 int size = atomic_load_explicit(&a->size, memory_order_relaxed);
193 x = atomic_load_explicit(&a->buffer[t % size], memory_order_relaxed);
196 @Potential_commit_point_define: true
197 @Label: Steal_Potential_Read_Buffer
200 /**** detected correctness failure ****/
201 bool succ = atomic_compare_exchange_strong_explicit(&q->top, &t, t + 1,
202 memory_order_seq_cst, memory_order_relaxed);
205 @Commit_point_define_check: succ
206 @Label: Steal_CAS_Top
212 @Additional_ordering_point_define_check: !succ
213 @Label: Steal_Additional_Point
219 @Commit_point_define: succ
220 @Potential_commit_point_label: Steal_Potential_Read_Buffer
221 @Label: Steal_Read_Buffer