VNFs/DPPD-PROX/heap.c

   1 /*
   2 // Copyright (c) 2010-2017 Intel Corporation
   3 //
   4 // Licensed under the Apache License, Version 2.0 (the "License");
   5 // you may not use this file except in compliance with the License.
   6 // You may obtain a copy of the License at
   7 //
   8 //     http://www.apache.org/licenses/LICENSE-2.0
   9 //
  10 // Unless required by applicable law or agreed to in writing, software
  11 // distributed under the License is distributed on an "AS IS" BASIS,
  12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 // See the License for the specific language governing permissions and
  14 // limitations under the License.
  15 */
  16
  17 #include <string.h>
  18 #include <stdio.h>
  19 #include <stddef.h>
  20 #include <rte_version.h>
  21 #include <rte_prefetch.h>
  22 #include <rte_memory.h>
  23
  24 #include "prox_malloc.h"
  25 #include "prox_assert.h"
  26 #include "heap.h"
  27 #include "log.h"
  28
  29 #include <string.h>
  30 #include <stddef.h>
  31 #include <stdlib.h>
  32
  33 struct heap_elem {
  34         uint64_t priority;
  35         struct heap_ref *ref;
  36         struct heap_elem *prev;
  37         struct heap_elem *next;
  38         struct heap_elem *child;
  39 };
  40
  41 struct strl {
  42         char *str;
  43         size_t len;
  44 };
  45
  46 int heap_top_is_lower(struct heap *h, uint64_t prio)
  47 {
  48         return !heap_is_empty(h) && h->top->priority < prio;
  49 }
  50
  51 static int heap_elem_check(struct heap_elem *e, int is_top)
  52 {
  53         if (!e)
  54                 return 1;
  55         if (e != e->prev &&
  56             e != e->next &&
  57             e != e->child)
  58                 return 1;
  59         else
  60                 return 0;
  61
  62         if (is_top && e->prev != NULL)
  63                 return 0;
  64         if (!is_top && e->prev == NULL)
  65                 return 0;
  66
  67         if (e->next) {
  68                 if (e->next->prev != e)
  69                         return 0;
  70
  71                 if (heap_elem_check(e->next, 0))
  72                         return 1;
  73                 else
  74                         return 0;
  75         }
  76
  77         if (e->child) {
  78                 if (e->child->prev != e)
  79                         return 0;
  80
  81                 if (heap_elem_check(e->child, 0))
  82                         return 1;
  83                 else
  84                         return 0;
  85         }
  86
  87         return 1;
  88 }
  89
  90 static int heap_elem_in_heap_elem(struct heap_elem *in, struct heap_elem *find)
  91 {
  92         if (in == find)
  93                 return 1;
  94
  95         if (in->next) {
  96                 if (heap_elem_in_heap_elem(in->next, find))
  97                         return 1;
  98         }
  99         if (in->child) {
 100                 if (heap_elem_in_heap_elem(in->child, find))
 101                         return 1;
 102         }
 103
 104         return 0;
 105 }
 106
 107 static int heap_elem_in_heap(struct heap *h, struct heap_elem *e)
 108 {
 109         if (h->top == NULL)
 110                 return 0;
 111
 112         return heap_elem_in_heap_elem(h->top, e);
 113 }
 114
 115 static int heap_elem_is_avail(struct heap *h, struct heap_elem *e)
 116 {
 117         for (uint32_t i = 0; i < h->n_avail; ++i) {
 118                 if (h->avail[i] == e)
 119                         return 1;
 120         }
 121         return 0;
 122 }
 123
 124 static uint32_t heap_elem_calc_size(struct heap_elem *e)
 125 {
 126         int ret = 0;
 127
 128         if (e)
 129                 ret++;
 130         else
 131                 return ret;
 132
 133         if (e->next)
 134                 ret += heap_elem_calc_size(e->next);
 135         if (e->child)
 136                 ret += heap_elem_calc_size(e->child);
 137         return ret;
 138 }
 139
 140 static uint32_t heap_calc_size(struct heap *h)
 141 {
 142         return heap_elem_calc_size(h->top);
 143 }
 144
 145 static void cat_indent(struct strl *s, int indent)
 146 {
 147         size_t r;
 148
 149         if (s->len < 50)
 150                 return ;
 151
 152         for (int i = 0; i < indent; ++i) {
 153                 r = snprintf(s->str, s->len, " ");
 154                 s->str += r;
 155                 s->len -= r;
 156         }
 157 }
 158
 159 static void cat_priority(struct strl *s, uint64_t priority)
 160 {
 161         size_t r;
 162
 163         if (s->len < 50)
 164                 return ;
 165
 166         r = snprintf(s->str, s->len, "%"PRIu64"\n", priority);
 167         s->str += r;
 168         s->len -= r;
 169 }
 170
 171 static void heap_print2(struct heap_elem *e, int indent, struct strl *s)
 172 {
 173         size_t r;
 174
 175         cat_indent(s, indent);
 176         cat_priority(s, e->priority);
 177
 178         struct heap_elem *child = e->child;
 179
 180         while (child) {
 181                 heap_print2(child, indent + 1, s);
 182                 child = child->next;
 183         }
 184 }
 185
 186 static void heap_print3(struct heap_elem *e, char *result, size_t buf_len)
 187 {
 188         struct strl s;
 189
 190         s.str = result;
 191         s.len = buf_len;
 192
 193         heap_print2(e, 0, &s);
 194 }
 195
 196 void heap_print(struct heap *h, char *result, size_t buf_len)
 197 {
 198         if (h->n_elems == 0) {
 199                 *result = 0;
 200                 return ;
 201         }
 202
 203         heap_print3(h->top, result, buf_len);
 204 }
 205
 206 struct heap *heap_create(uint32_t max_elems, int socket_id)
 207 {
 208         struct heap *ret;
 209         size_t mem_size = 0;
 210         size_t elem_mem = 0;
 211         struct heap_elem *e;
 212
 213         /* max_elems + 1 since index start at 1. Store total number of
 214            elements in the first entry (which is unused otherwise). */
 215         mem_size += sizeof(struct heap);
 216         mem_size += sizeof(((struct heap *)0)->top) * max_elems;
 217         mem_size = RTE_CACHE_LINE_ROUNDUP(mem_size);
 218         elem_mem = mem_size;
 219         mem_size += sizeof(*((struct heap *)0)->top) * max_elems;
 220         ret = prox_zmalloc(mem_size, socket_id);
 221         if (!ret)
 222                 return NULL;
 223
 224         e = (struct heap_elem *)(((uint8_t *)ret) + elem_mem);
 225         PROX_ASSERT((void *)&e[max_elems] <= (void *)ret + mem_size);
 226
 227         for (uint32_t i = 0; i < max_elems; ++i) {
 228                 PROX_ASSERT(e->priority == 0);
 229                 PROX_ASSERT(e->ref == 0);
 230                 PROX_ASSERT(e->prev == 0);
 231                 PROX_ASSERT(e->next == 0);
 232                 PROX_ASSERT(e->child == 0);
 233
 234                 ret->avail[ret->n_avail++] = e++;
 235         }
 236
 237         PROX_ASSERT(ret->n_elems + ret->n_avail == max_elems);
 238         return ret;
 239 }
 240
 241 static struct heap_elem *heap_get(struct heap *h)
 242 {
 243         PROX_ASSERT(h->n_avail);
 244
 245         return h->avail[--h->n_avail];
 246 }
 247
 248 static void heap_put(struct heap *h, struct heap_elem *e)
 249 {
 250         h->avail[h->n_avail++] = e;
 251 }
 252
 253 void heap_add(struct heap *h, struct heap_ref *ref, uint64_t priority)
 254 {
 255         PROX_ASSERT(h);
 256         PROX_ASSERT(ref);
 257         PROX_ASSERT(ref->elem == NULL);
 258         PROX_ASSERT(heap_elem_check(h->top, 1));
 259         PROX_ASSERT(h->n_elems == heap_calc_size(h));
 260
 261         if (h->n_elems == 0) {
 262                 h->n_elems++;
 263                 h->top = heap_get(h);
 264
 265                 h->top->priority = priority;
 266                 h->top->ref = ref;
 267                 ref->elem = h->top;
 268                 h->top->prev = NULL;
 269                 h->top->next = NULL;
 270                 h->top->child = NULL;
 271
 272                 PROX_ASSERT(heap_elem_check(h->top, 1));
 273                 PROX_ASSERT(h->n_elems == heap_calc_size(h));
 274                 return ;
 275         }
 276
 277         h->n_elems++;
 278         /* New element becomes new top */
 279         if (h->top->priority > priority) {
 280                 struct heap_elem *n = heap_get(h);
 281
 282                 n->priority = priority;
 283                 n->ref = ref;
 284                 ref->elem = n;
 285                 n->prev = NULL;
 286                 n->next = NULL;
 287                 n->child = h->top;
 288
 289                 h->top->prev = n;
 290                 h->top = n;
 291         }
 292         /* New element is added as first sibling */
 293         else {
 294                 struct heap_elem *n = heap_get(h);
 295                 n->priority = priority;
 296                 n->ref = ref;
 297                 ref->elem = n;
 298                 n->prev = h->top;
 299                 n->next = h->top->child;
 300                 if (h->top->child)
 301                         h->top->child->prev = n;
 302                 n->child = NULL;
 303                 h->top->child = n;
 304         }
 305
 306         PROX_ASSERT(heap_elem_check(h->top, 1));
 307         PROX_ASSERT(h->n_elems == heap_calc_size(h));
 308 }
 309
 310 static void heap_merge_tops_left(struct heap_elem *left, struct heap_elem *right)
 311 {
 312         PROX_ASSERT(left->priority <= right->priority);
 313         PROX_ASSERT(left != right);
 314
 315         /* right moves down and becomes first child of left. */
 316         left->next = right->next;
 317         if (right->next)
 318                 right->next->prev = left;
 319
 320         right->next = left->child;
 321         if (left->child)
 322                 left->child->prev = right;
 323
 324         /* right->prev is now referring to parent since right is the
 325            new first child. */
 326         left->child = right;
 327 }
 328
 329 static void heap_merge_tops_right(struct heap_elem *left, struct heap_elem *right)
 330 {
 331         PROX_ASSERT(left->priority >= right->priority);
 332         PROX_ASSERT(left != right);
 333
 334         /* Left goes down one layer */
 335         right->prev = left->prev;
 336         if (left->prev)
 337                 left->prev->next = right;
 338
 339         left->next = right->child;
 340         if (right->child)
 341                 right->child->prev = left;
 342
 343         left->prev = right;
 344         right->child = left;
 345 }
 346
 347 static struct heap_elem *heap_merge_children(struct heap_elem *e)
 348 {
 349         struct heap_elem *next = e->next;
 350         struct heap_elem *tmp;
 351         struct heap_elem *prev;
 352         struct heap_elem *first;
 353
 354         PROX_ASSERT(e);
 355         int cnt = 0;
 356         /* TODO: is this really needed? */
 357         if (!next)
 358                 return e;
 359
 360         if (e->priority < next->priority)
 361                 first = e;
 362         else
 363                 first = next;
 364
 365         /* Forward pass */
 366         do {
 367                 cnt++;
 368                 tmp = next->next;
 369                 rte_prefetch0(tmp);
 370                 if (e->priority < next->priority) {
 371                         heap_merge_tops_left(e, next);
 372                         prev = e;
 373                         PROX_ASSERT(e->child == next);
 374                 }
 375                 else {
 376                         heap_merge_tops_right(e, next);
 377                         PROX_ASSERT(next->child == e);
 378                         prev = next;
 379                 }
 380
 381                 if (tmp) {
 382                         tmp->prev = prev;
 383                         e = tmp;
 384                         /* Next could be empty, (uneven # children) */
 385                         if (!tmp->next)
 386                                 break;
 387                         next = tmp->next;
 388                 }
 389                 else {
 390                         /* Even number of nodes, after breaking set e
 391                            to the last merged pair top */
 392                         if (e->priority >= next->priority)
 393                                 e = next;
 394                         break;
 395                 }
 396         } while (1);
 397         /* Backward pass, merge everything with the right until the
 398            first child */
 399         while (first != e) {
 400                 prev = e->prev;
 401
 402                 if (e->priority < prev->priority) {
 403                         heap_merge_tops_right(prev, e);
 404                         if (prev == first) {
 405                                 first = e;
 406                                 break;
 407                         }
 408                 }
 409                 else {
 410                         heap_merge_tops_left(prev, e);
 411                         e = prev;
 412                 }
 413         }
 414         return first;
 415 }
 416
 417 static int heap_elem_first_sibling(const struct heap_elem *e)
 418 {
 419         return e->prev->child == e;
 420 }
 421
 422 void heap_del(struct heap *h, struct heap_ref *d)
 423 {
 424         struct heap_elem *del = d->elem;
 425
 426         PROX_ASSERT(del);
 427         PROX_ASSERT(heap_elem_in_heap(h, del));
 428         PROX_ASSERT(!heap_elem_is_avail(h, del));
 429         PROX_ASSERT(h->n_elems == heap_calc_size(h));
 430         PROX_ASSERT(heap_elem_check(h->top, 1));
 431         PROX_ASSERT(h->top->next == NULL);
 432         PROX_ASSERT(h->top->prev == NULL);
 433
 434         d->elem = NULL;
 435         /* Del is at the top */
 436         if (del->prev == NULL) {
 437                 PROX_ASSERT(del == h->top);
 438                 if (del->child) {
 439                         del->child->prev = NULL;
 440                         h->top = heap_merge_children(del->child);
 441                         PROX_ASSERT(h->top);
 442                 }
 443                 else {
 444                         h->top = NULL;
 445                 }
 446
 447                 h->n_elems--;
 448                 heap_put(h, del);
 449                 PROX_ASSERT(heap_elem_check(h->top, 1));
 450                 PROX_ASSERT(h->n_elems == 0 || h->top != NULL);
 451                 PROX_ASSERT(h->n_elems == heap_calc_size(h));
 452                 return ;
 453         }
 454         PROX_ASSERT(del != h->top);
 455
 456         /* Del is somewhere in a lower layer. If it the first child,
 457            need to fix the parent differently. */
 458         if (heap_elem_first_sibling(del)) {
 459                 del->prev->child = del->next;
 460                 if (del->next)
 461                         del->next->prev = del->prev;
 462         }
 463         else {
 464                 del->prev->next = del->next;
 465                 if (del->next)
 466                         del->next->prev = del->prev;
 467         }
 468
 469         struct heap_elem *top2 = del->child;
 470
 471         /* If the node to be deleted has children, there is more work:
 472            merge the children into a single heap and merge with
 473            top. If there are no children, then the disconnection above
 474            is enough. */
 475         if (top2) {
 476                 top2->prev = NULL;
 477                 top2 = heap_merge_children(top2);
 478
 479                 /* Merge top2 with h->top */
 480                 if (h->top->priority < top2->priority) {
 481                         top2->next = h->top->child;
 482                         top2->prev = h->top;
 483                         if (h->top->child)
 484                                 h->top->child->prev = top2;
 485
 486                         h->top->child = top2;
 487                 }
 488                 else {
 489                         h->top->next = top2->child;
 490                         h->top->prev = top2;
 491                         if (top2->child)
 492                                 top2->child->prev = h->top;
 493
 494                         top2->child = h->top;
 495                         h->top = top2;
 496                 }
 497
 498         }
 499         h->n_elems--;
 500         heap_put(h, del);
 501
 502         PROX_ASSERT(heap_elem_check(h->top, 1));
 503         PROX_ASSERT(h->n_elems == heap_calc_size(h));
 504 }
 505
 506 struct heap_ref *heap_pop(struct heap *h)
 507 {
 508         if (h->n_elems == 0)
 509                 return NULL;
 510
 511         struct heap_ref *ret = h->top->ref;
 512
 513         heap_del(h, h->top->ref);
 514         return ret;
 515 }