benchmark/chase-lev-deque-bugfix/deque.c

   1 #include <stdatomic.h>
   2 #include <inttypes.h>
   3 #include "deque.h"
   4 #include <stdlib.h>
   5 #include <stdio.h>
   6
   7 Deque * create() {
   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);
  14         return q;
  15 }
  16
  17
  18 /**
  19         @Begin
  20         @Interface_define: Take
  21         @End
  22 */
  23 int take(Deque *q) {
  24         size_t b = atomic_load_explicit(&q->bottom, memory_order_relaxed) - 1;
  25         Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
  26         atomic_store_explicit(&q->bottom, b, memory_order_relaxed);
  27         /**** detected correctness ****/
  28         atomic_thread_fence(memory_order_seq_cst);
  29         size_t t = atomic_load_explicit(&q->top, memory_order_relaxed);
  30         /**
  31                 @Begin
  32                 @Commit_point_define_check: t > b
  33                 @Label: Take_Point1
  34                 @End
  35         */
  36         int x;
  37         if (t <= b) {
  38                 /* Non-empty queue. */
  39                 int size = atomic_load_explicit(&a->size,memory_order_relaxed);
  40                 x = atomic_load_explicit(&a->buffer[b % size], memory_order_relaxed);
  41                 /**
  42                         @Begin
  43                         @Commit_point_define_check: t != b
  44                         @Label: Take_Point2
  45                         @End
  46                 */
  47                 if (t == b) {
  48                         /* Single last element in queue. */
  49                         //FIXME: weaken the following seq_cst causes no spec problem
  50                         bool succ = atomic_compare_exchange_strong_explicit(&q->top, &t, t +
  51                                 1, memory_order_seq_cst, memory_order_relaxed);
  52                         /**
  53                                 @Begin
  54                                 @Commit_point_define_check: true
  55                                 @Label: Take_Point3
  56                                 @End
  57                         */
  58                         if (!succ) {
  59                                 /* Failed race. */
  60                                 x = EMPTY;
  61                         }
  62                         atomic_store_explicit(&q->bottom, b + 1, memory_order_relaxed);
  63                 }
  64         } else { /* Empty queue. */
  65                 x = EMPTY;
  66                 atomic_store_explicit(&q->bottom, b + 1, memory_order_relaxed);
  67         }
  68         return x;
  69 }
  70
  71 void resize(Deque *q) {
  72         Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
  73         size_t size=atomic_load_explicit(&a->size, memory_order_relaxed);
  74         size_t new_size=size << 1;
  75         Array *new_a = (Array *) calloc(1, new_size * sizeof(atomic_int) + sizeof(Array));
  76         size_t top=atomic_load_explicit(&q->top, memory_order_relaxed);
  77         size_t bottom=atomic_load_explicit(&q->bottom, memory_order_relaxed);
  78         atomic_store_explicit(&new_a->size, new_size, memory_order_relaxed);
  79         size_t i;
  80         for(i=top; i < bottom; i++) {
  81                 atomic_store_explicit(&new_a->buffer[i % new_size], atomic_load_explicit(&a->buffer[i % size], memory_order_relaxed), memory_order_relaxed);
  82         }
  83         /**** detected UL ****/
  84         atomic_store_explicit(&q->array, new_a, memory_order_release);
  85         //printf("resize\n");
  86 }
  87
  88 /**
  89         @Begin
  90         @Interface_define: Push
  91         @End
  92 */
  93 void push(Deque *q, int x) {
  94         size_t b = atomic_load_explicit(&q->bottom, memory_order_relaxed);
  95         /**** detected correctness ****/
  96         size_t t = atomic_load_explicit(&q->top, memory_order_acquire);
  97         Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
  98         if (b - t > atomic_load_explicit(&a->size, memory_order_relaxed) - 1) /* Full queue. */ {
  99                 resize(q);
 100                 //Bug in paper...should have next line...
 101                 a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
 102                 /**
 103                         @Begin
 104                         @Commit_point_define_check: true
 105                         @Label: Push_Read_Array
 106                         @End
 107                 */
 108         }
 109         int size = atomic_load_explicit(&a->size, memory_order_relaxed);
 110
 111         atomic_store_explicit(&a->buffer[b % size], x, memory_order_relaxed);
 112         /**
 113                 @Begin
 114                 @Commit_point_define_check: true
 115                 @Label: Push_Update_Buffer
 116                 @End
 117         */
 118         /**** correctness error ****/
 119         atomic_thread_fence(memory_order_release);
 120
 121         atomic_store_explicit(&q->bottom, b + 1, memory_order_relaxed);
 122         /**
 123                 @Begin
 124                 @Commit_point_define_check: true
 125                 @Label: Push_Update_Bottom
 126                 @End
 127         */
 128 }
 129
 130 /**
 131         @Begin
 132         @Interface_define: Steal
 133         @End
 134 */
 135 int steal(Deque *q) {
 136         //FIXME: weaken the following acquire causes no spec problem
 137         size_t t = atomic_load_explicit(&q->top, memory_order_acquire);
 138         //FIXME: remove the fence causes no error and fewer executions..
 139         atomic_thread_fence(memory_order_seq_cst);
 140         /**** detected UL ****/
 141         size_t b = atomic_load_explicit(&q->bottom, memory_order_acquire);
 142         /**
 143                 @Begin
 144                 @Commit_point_define_check: t >= b
 145                 @Label: Steal_Point1
 146                 @End
 147         */
 148         int x = EMPTY;
 149         if (t < b) {
 150                 /* Non-empty queue. */
 151                 /**** detected UL ****/
 152                 Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_acquire);
 153                 int size = atomic_load_explicit(&a->size, memory_order_relaxed);
 154                 x = atomic_load_explicit(&a->buffer[t % size], memory_order_relaxed);
 155                 /**
 156                         @Begin
 157                         @Potential_commit_point_define: true
 158                         @Label: Potential_Steal
 159                         @End
 160                 */
 161                 /**** detected correctness failure ****/
 162                 bool succ = atomic_compare_exchange_strong_explicit(&q->top, &t, t + 1,
 163                         memory_order_seq_cst, memory_order_relaxed);
 164                 /**
 165                         @Begin
 166                         @Commit_point_define_check: !succ
 167                         @Label: Steal_Point2
 168                         @End
 169                 */
 170
 171                 /**
 172                         @Begin
 173                         @Commit_point_define: succ
 174                         @Potential_commit_point_label: Potential_Steal
 175                         @Label: Steal_Point3
 176                         @End
 177                 */
 178                 if (!succ) {
 179                         /* Failed race. */
 180                         return ABORT;
 181                 }
 182         }
 183         return x;
 184 }