cdschecker_modified_benchmarks/ms-queue/my_queue.c.correct

   1 #include <threads.h>
   2 #include <stdlib.h>
   3 #include "librace.h"
   4 #include "model-assert.h"
   5
   6 #include "queue.h"
   7
   8 #define relaxed memory_order_relaxed
   9 #define release memory_order_release
  10 #define acquire memory_order_acquire
  11
  12 #define MAX_FREELIST 4 /* Each thread can own up to MAX_FREELIST free nodes */
  13 #define INITIAL_FREE 2 /* Each thread starts with INITIAL_FREE free nodes */
  14
  15 #define POISON_IDX 0x666
  16
  17 static unsigned int (*free_lists)[MAX_FREELIST];
  18
  19 /* Search this thread's free list for a "new" node */
  20 static unsigned int new_node()
  21 {
  22         int i;
  23         int t = get_thread_num();
  24         for (i = 0; i < MAX_FREELIST; i++) {
  25                 //unsigned int node = load_32(&free_lists[t][i]);
  26                 unsigned int node = free_lists[t][i];
  27                 if (node) {
  28                         //store_32(&free_lists[t][i], 0);
  29                         free_lists[t][i] = 0;
  30                         return node;
  31                 }
  32         }
  33         /* free_list is empty? */
  34         MODEL_ASSERT(0);
  35         return 0;
  36 }
  37
  38 /* Simulate the fact that when a node got recycled, it will get assigned to the
  39  * same queue or for other usage */
  40 void simulateRecycledNodeUpdate(queue_t *q, unsigned int node) {
  41         atomic_store_explicit(&q->nodes[node].next, -1, memory_order_release);
  42 }
  43
  44
  45 /* Place this node index back on this thread's free list */
  46 static void reclaim(unsigned int node)
  47 {
  48         int i;
  49         int t = get_thread_num();
  50
  51         /* Don't reclaim NULL node */
  52         //MODEL_ASSERT(node);
  53
  54         for (i = 0; i < MAX_FREELIST; i++) {
  55                 /* Should never race with our own thread here */
  56                 //unsigned int idx = load_32(&free_lists[t][i]);
  57                 unsigned int idx = free_lists[t][i];
  58
  59                 /* Found empty spot in free list */
  60                 if (idx == 0) {
  61                         //store_32(&free_lists[t][i], node);
  62                         free_lists[t][i] = node;
  63                         return;
  64                 }
  65         }
  66         /* free list is full? */
  67         //MODEL_ASSERT(0);
  68 }
  69
  70 void init_queue(queue_t *q, int num_threads)
  71 {
  72         int i, j;
  73
  74         /* Initialize each thread's free list with INITIAL_FREE pointers */
  75         /* The actual nodes are initialized with poison indexes */
  76         free_lists = ( unsigned int (*)[MAX_FREELIST] ) malloc(num_threads * sizeof(*free_lists));
  77         for (i = 0; i < num_threads; i++) {
  78                 for (j = 0; j < INITIAL_FREE; j++) {
  79                         free_lists[i][j] = 2 + i * MAX_FREELIST + j;
  80                         atomic_init(&q->nodes[free_lists[i][j]].next, MAKE_POINTER(POISON_IDX, 0));
  81                 }
  82         }
  83
  84         /* initialize queue */
  85         atomic_init(&q->head, MAKE_POINTER(1, 0));
  86         atomic_init(&q->tail, MAKE_POINTER(1, 0));
  87         atomic_init(&q->nodes[1].next, MAKE_POINTER(0, 0));
  88 }
  89
  90 /** @DeclareState: IntList *q;
  91 @Initial: q = new IntList;
  92 @Print:
  93         model_print("\tSTATE(q): ");
  94     printContainer(q);
  95         model_print("\n"); */
  96
  97 /** @Transition: STATE(q)->push_back(val);
  98 @Print: model_print("\tENQ #%d: val=%d\n", ID, val); */
  99 void enqueue(queue_t *q, unsigned int val, int n)
 100 {
 101         int success = 0;
 102         unsigned int node;
 103         pointer tail;
 104         pointer next;
 105         pointer tmp;
 106
 107         node = new_node();
 108         //store_32(&q->nodes[node].value, val);
 109         q->nodes[node].value = val;
 110         tmp = atomic_load_explicit(&q->nodes[node].next, relaxed);
 111         set_ptr(&tmp, 0); // NULL
 112     // XXX-known-bug-#1: This is a found bug in AutoMO, and testcase4 can reveal
 113     // this known bug.
 114     // To reproduce, weaken the parameter "memory_order_release" to
 115     // "memory_order_relaxed", run "make" to recompile, and then run:
 116     // "./run.sh ./ms-queue/testcase4 -m2 -y -u3 -tSPEC"
 117         /**********    Detected KNOWN BUG (testcase4)    **********/
 118         atomic_store_explicit(&q->nodes[node].next, tmp, release);
 119
 120         while (!success) {
 121         // XXX-injection-#1: To reproduce, weaken the parameter
 122         // "memory_order_acquire" to "memory_order_relaxed", run "make" to
 123         // recompile, and then run:
 124         // "./run.sh ./ms-queue/testcase2 -m2 -y -u3 -tSPEC"
 125                 /**********    Detected UL (testcase2)    **********/
 126                 tail = atomic_load_explicit(&q->tail, acquire);
 127         // XXX-injection-#2: To reproduce, weaken the parameter
 128         // "memory_order_acquire" to "memory_order_relaxed", run "make" to
 129         // recompile, and then run:
 130         // "./run.sh ./ms-queue/testcase4 -m2 -y -u3 -tSPEC"
 131                 /**********    Detected Correctness (testcase4)    **********/
 132                 next = atomic_load_explicit(&q->nodes[get_ptr(tail)].next, acquire);
 133                 if (tail == atomic_load_explicit(&q->tail, relaxed)) {
 134
 135                         /* Check for uninitialized 'next' */
 136                         //MODEL_ASSERT(get_ptr(next) != POISON_IDX);
 137
 138                         if (get_ptr(next) == 0) { // == NULL
 139                                 pointer value = MAKE_POINTER(node, get_count(next) + 1);
 140                 // XXX-injection-#3: To reproduce, weaken the parameter
 141                 // "memory_order_release" to "memory_order_relaxed", run "make" to
 142                 // recompile, and then run:
 143                 // "./run.sh ./ms-queue/testcase1 -m2 -y -u3 -tSPEC"
 144                                 /**********    Detected Correctness (testcase1)    **********/
 145                                 success = atomic_compare_exchange_strong_explicit(&q->nodes[get_ptr(tail)].next,
 146                                                 &next, value, release, release);
 147                                 /** @OPClearDefine: success */
 148                         }
 149                         if (!success) {
 150                 // XXX-injection-#4: To reproduce, weaken the parameter
 151                 // "memory_order_acquire" to "memory_order_relaxed", run "make" to
 152                 // recompile, and then run:
 153                 // "./run.sh ./ms-queue/testcase2 -m2 -y -u3 -tSPEC"
 154                                 /**********    Detected UL (testcase2)    **********/
 155                                 unsigned int ptr = get_ptr(atomic_load_explicit(&q->nodes[get_ptr(tail)].next, acquire));
 156                                 pointer value = MAKE_POINTER(ptr,
 157                                                 get_count(tail) + 1);
 158                 // XXX-injection-#5: To reproduce, weaken the parameter
 159                 // "memory_order_release" to "memory_order_relaxed", run "make" to
 160                 // recompile, and then run:
 161                 // "./run.sh ./ms-queue/testcase2 -m2 -y -u3 -tSPEC"
 162                                 /**********    Detected Correctness (testcase2)    **********/
 163                                 atomic_compare_exchange_strong_explicit(&q->tail,
 164                                                 &tail, value,
 165                                                 release, release);
 166                                 thrd_yield();
 167                         }
 168                 }
 169         }
 170
 171     // XXX-injection-#6: To reproduce, weaken the parameter
 172     // "memory_order_release" to "memory_order_relaxed", run "make" to
 173     // recompile, and then run:
 174     // "./run.sh ./ms-queue/testcase1 -m2 -y -u3 -tSPEC"
 175         /**********    Detected Correctness (testcase1) **********/
 176         atomic_compare_exchange_strong_explicit(&q->tail,
 177                         &tail,
 178                         MAKE_POINTER(node, get_count(tail) + 1),
 179                         release, release);
 180 }
 181
 182 /** @Transition: S_RET = STATE(q)->empty() ? 0 : STATE(q)->front();
 183 if (S_RET && C_RET) STATE(q)->pop_front();
 184 @JustifyingPostcondition: if (!C_RET)
 185     return S_RET == C_RET;
 186 @PostCondition: return C_RET ? *retVal  == S_RET : true;
 187 @Print: model_print("\tDEQ #%d: C_RET=%d && *retVal=%d && S_RET=%d\n", ID,
 188             C_RET, *retVal, S_RET);
 189 */
 190 int dequeue(queue_t *q, unsigned int *retVal, unsigned int *reclaimNode)
 191 {
 192         int success = 0;
 193         pointer head;
 194         pointer tail;
 195         pointer next;
 196
 197         while (!success) {
 198         // XXX-injection-#7: To reproduce, weaken the parameter
 199         // "memory_order_acquire" to "memory_order_relaxed", run "make" to
 200         // recompile, and then run:
 201         // "./run.sh ./ms-queue/testcase3 -m2 -y -u3 -tSPEC"
 202                 /**********    Detected Correctness (testcase3)    **********/
 203                 head = atomic_load_explicit(&q->head, acquire);
 204         // To reproduce, weaken the parameter "memory_order_acquire" to
 205         // "memory_order_relaxed", run "make" to recompile, and then run:
 206         // "./run.sh ./ms-queue/testcase4 -m2 -y -u3 -tSPEC"
 207         // XXX-known-bug-#2: This is another known bug, and testcase2 can reveal
 208         // this known bug
 209                 /**********    Detected KNOWN BUG (testcase2)    **********/
 210                 tail = atomic_load_explicit(&q->tail, acquire);
 211
 212         // XXX-injection-#8: To reproduce, weaken the parameter
 213         // "memory_order_acquire" to "memory_order_relaxed", run "make" to
 214         // recompile, and then run:
 215         // "./run.sh ./ms-queue/testcase1 -m2 -y -u3 -tSPEC"
 216                 /**********    Detected Correctness (testcase1) **********/
 217                 next = atomic_load_explicit(&q->nodes[get_ptr(head)].next, acquire);
 218                 /** @OPClearDefine: true */
 219                 if (atomic_load_explicit(&q->head, relaxed) == head) {
 220                         if (get_ptr(head) == get_ptr(tail)) {
 221
 222                                 /* Check for uninitialized 'next' */
 223                                 MODEL_ASSERT(get_ptr(next) != POISON_IDX);
 224
 225                                 if (get_ptr(next) == 0) { // NULL
 226                                         return false; // NULL
 227                                 }
 228
 229                 // XXX-injection-#9: To reproduce, weaken the parameter
 230                 // "memory_order_release" to "memory_order_relaxed", run "make" to
 231                 // recompile, and then run:
 232                 // "./run.sh ./ms-queue/testcase2 -m2 -y -u3 -tSPEC"
 233                                 /**********    Detected UL (testcase2)    **********/
 234                                 atomic_compare_exchange_strong_explicit(&q->tail,
 235                                                 &tail,
 236                                                 MAKE_POINTER(get_ptr(next), get_count(tail) + 1),
 237                                                 release, release);
 238                                 thrd_yield();
 239                         } else {
 240                                 //*retVal = load_32(&q->nodes[get_ptr(next)].value);
 241                                 *retVal = q->nodes[get_ptr(next)].value;
 242
 243                 // XXX-injection-#10: To reproduce, weaken the parameter
 244                 // "memory_order_release" to "memory_order_relaxed", run "make" to
 245                 // recompile, and then run:
 246                 // "./run.sh ./ms-queue/testcase3 -m2 -y -u3 -tSPEC"
 247                                 /**********    Detected Correctness (testcase3)    **********/
 248                                 success = atomic_compare_exchange_strong_explicit(&q->head,
 249                                                 &head,
 250                                                 MAKE_POINTER(get_ptr(next), get_count(head) + 1),
 251                                                 release, release);
 252                                 if (!success)
 253                                         thrd_yield();
 254                         }
 255                 }
 256         }
 257         *reclaimNode = get_ptr(head);
 258         reclaim(get_ptr(head));
 259         return true;
 260 }