fc8e02abb28e05ae79bdf09958ad7cca5635935e
[cdsspec-compiler.git] / benchmark / ms-queue / my_queue.c
1 #include <threads.h>
2 #include <stdlib.h>
3 #include "librace.h"
4 #include "model-assert.h"
5
6 #include "my_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                 if (node) {
27                         store_32(&free_lists[t][i], 0);
28                         return node;
29                 }
30         }
31         /* free_list is empty? */
32         MODEL_ASSERT(0);
33         return 0;
34 }
35
36 /* Place this node index back on this thread's free list */
37 static void reclaim(unsigned int node)
38 {
39         int i;
40         int t = get_thread_num();
41
42         /* Don't reclaim NULL node */
43         MODEL_ASSERT(node);
44
45         for (i = 0; i < MAX_FREELIST; i++) {
46                 /* Should never race with our own thread here */
47                 unsigned int idx = load_32(&free_lists[t][i]);
48
49                 /* Found empty spot in free list */
50                 if (idx == 0) {
51                         store_32(&free_lists[t][i], node);
52                         return;
53                 }
54         }
55         /* free list is full? */
56         MODEL_ASSERT(0);
57 }
58
59 void init_queue(queue_t *q, int num_threads)
60 {
61         int i, j;
62
63         /* Initialize each thread's free list with INITIAL_FREE pointers */
64         /* The actual nodes are initialized with poison indexes */
65         free_lists = malloc(num_threads * sizeof(*free_lists));
66         for (i = 0; i < num_threads; i++) {
67                 for (j = 0; j < INITIAL_FREE; j++) {
68                         free_lists[i][j] = 2 + i * MAX_FREELIST + j;
69                         atomic_init(&q->nodes[free_lists[i][j]].next, MAKE_POINTER(POISON_IDX, 0));
70                 }
71         }
72
73         /* initialize queue */
74         atomic_init(&q->head, MAKE_POINTER(1, 0));
75         atomic_init(&q->tail, MAKE_POINTER(1, 0));
76         atomic_init(&q->nodes[1].next, MAKE_POINTER(0, 0));
77 }
78
79 /**
80         @Begin
81         @Global_define:
82                 typedef struct tag_elem {
83                         Tag id;
84                         unsigned int data;
85                         
86                         tag_elem(Tag _id, unsigned int _data) {
87                                 id = _id;
88                                 data = _data;
89                         }
90                 } tag_elem_t;
91
92                 spec_queue<tag_elem_t> __queue;
93                 Tag __tag;
94         @Happens_before:
95                 # Only check the happens-before relationship according to the id of the
96                 # commit_point_set. For commit_point_set that has same ID, A -> B means
97                 # B happens after the previous A.
98                 Enqueue -> Dequeue
99         @End
100 */
101
102 /**
103         @Begin
104         @Interface: Enqueue
105         @Commit_point_set: Enqueue_Success_Point
106         @ID: __tag.getCurAndInc()
107         @Action:
108                 # __ID__ is an internal macro that refers to the id of the current
109                 # interface call
110                 @Code:
111                 __queue.enqueue(tag_elem_t(__ID__, val));
112         @End
113 */
114 void enqueue(queue_t *q, unsigned int val)
115 {
116         int success = 0;
117         unsigned int node;
118         pointer tail;
119         pointer next;
120         pointer tmp;
121
122         node = new_node();
123         store_32(&q->nodes[node].value, val);
124         tmp = atomic_load_explicit(&q->nodes[node].next, relaxed);
125         set_ptr(&tmp, 0); // NULL
126         atomic_store_explicit(&q->nodes[node].next, tmp, relaxed);
127
128         while (!success) {
129                 tail = atomic_load_explicit(&q->tail, acquire);
130                 next = atomic_load_explicit(&q->nodes[get_ptr(tail)].next, acquire);
131                 if (tail == atomic_load_explicit(&q->tail, relaxed)) {
132
133                         /* Check for uninitialized 'next' */
134                         MODEL_ASSERT(get_ptr(next) != POISON_IDX);
135
136                         if (get_ptr(next) == 0) { // == NULL
137                                 pointer value = MAKE_POINTER(node, get_count(next) + 1);
138                                 success = atomic_compare_exchange_strong_explicit(&q->nodes[get_ptr(tail)].next,
139                                                 &next, value, release, release);
140                         }
141                         if (!success) {
142                                 unsigned int ptr = get_ptr(atomic_load_explicit(&q->nodes[get_ptr(tail)].next, acquire));
143                                 pointer value = MAKE_POINTER(ptr,
144                                                 get_count(tail) + 1);
145                                 int commit_success = 0;
146                                 commit_success = atomic_compare_exchange_strong_explicit(&q->tail,
147                                                 &tail, value, release, release);
148                                 /**
149                                         @Begin
150                                         @Commit_point_define_check: __ATOMIC_RET__ == true
151                                         @Label: Enqueue_Success_Point
152                                         @End
153                                 */
154                                 thrd_yield();
155                         }
156                 }
157         }
158         atomic_compare_exchange_strong_explicit(&q->tail,
159                         &tail,
160                         MAKE_POINTER(node, get_count(tail) + 1),
161                         release, release);
162 }
163
164 /**
165         @Begin
166         @Interface: Dequeue
167         @Commit_point_set: Dequeue_Success_Point
168         @ID: __queue.peak().tag
169         @Action:
170                 @Code:
171                 unsigned int _Old_Val = __queue.dequeue().data;
172         @Post_check:
173                 _Old_Val == __RET__
174         @End
175 */
176 unsigned int dequeue(queue_t *q)
177 {
178         unsigned int value;
179         int success = 0;
180         pointer head;
181         pointer tail;
182         pointer next;
183
184         while (!success) {
185                 head = atomic_load_explicit(&q->head, acquire);
186                 tail = atomic_load_explicit(&q->tail, relaxed);
187                 next = atomic_load_explicit(&q->nodes[get_ptr(head)].next, acquire);
188                 if (atomic_load_explicit(&q->head, relaxed) == head) {
189                         if (get_ptr(head) == get_ptr(tail)) {
190
191                                 /* Check for uninitialized 'next' */
192                                 MODEL_ASSERT(get_ptr(next) != POISON_IDX);
193
194                                 if (get_ptr(next) == 0) { // NULL
195                                         return 0; // NULL
196                                 }
197                                 atomic_compare_exchange_strong_explicit(&q->tail,
198                                                 &tail,
199                                                 MAKE_POINTER(get_ptr(next), get_count(tail) + 1),
200                                                 release, release);
201                                 thrd_yield();
202                         } else {
203                                 value = load_32(&q->nodes[get_ptr(next)].value);
204                                 success = atomic_compare_exchange_strong_explicit(&q->head,
205                                                 &head,
206                                                 MAKE_POINTER(get_ptr(next), get_count(head) + 1),
207                                                 release, release);
208                                 /**
209                                         @Begin
210                                         @Commit_point_define_check: __ATOMIC_RET__ == true
211                                         @Label: Dequeue_Success_Point
212                                         @End
213                                 */
214                                 if (!success)
215                                         thrd_yield();
216                         }
217                 }
218         }
219         reclaim(get_ptr(head));
220         return value;
221 }