lttv/lttv/hook.c

   1 /* This file is part of the Linux Trace Toolkit viewer
   2  * Copyright (C) 2003-2004 Michel Dagenais
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License Version 2 as
   6  * published by the Free Software Foundation;
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write to the Free Software
  15  * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  16  * MA 02111-1307, USA.
  17  */
  18
  19 #ifdef HAVE_CONFIG_H
  20 #include <config.h>
  21 #endif
  22
  23 #include <lttv/hook.h>
  24 #include <ltt/compiler.h>
  25 #include <ltt/ltt.h>
  26
  27 typedef struct _LttvHookClosure {
  28         LttvHook      hook;
  29         void         *hook_data;
  30         LttvHookPrio  prio;
  31         guint         ref_count;
  32 } LttvHookClosure;
  33
  34 gint lttv_hooks_prio_compare(LttvHookClosure *a, LttvHookClosure *b)
  35 {
  36         gint ret=0;
  37         if(a->prio < b->prio) ret = -1;
  38         else if(a->prio > b->prio) ret = 1;
  39         return ret;
  40 }
  41
  42
  43 LttvHooks *lttv_hooks_new(void)
  44 {
  45         return g_array_new(FALSE, FALSE, sizeof(LttvHookClosure));
  46 }
  47
  48
  49 void lttv_hooks_destroy(LttvHooks *h)
  50 {
  51         g_log(G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, "lttv_hooks_destroy()");
  52         g_array_free(h, TRUE);
  53 }
  54
  55
  56 void lttv_hooks_add(LttvHooks *h, LttvHook f, void *hook_data, LttvHookPrio p)
  57 {
  58         LttvHookClosure *c, new_c;
  59         guint i;
  60
  61         if(unlikely(h == NULL))g_error("Null hook added");
  62
  63         new_c.hook = f;
  64         new_c.hook_data = hook_data;
  65         new_c.prio = p;
  66         new_c.ref_count = 1;
  67
  68         /* Preliminary check for duplication */
  69         /* only hook and hook data is checked */
  70         for(i = 0; i < h->len; i++) {
  71                 c = &g_array_index(h, LttvHookClosure, i);
  72                 if(new_c.hook == c->hook && new_c.hook_data == c->hook_data) {
  73                         g_assert(new_c.prio == c->prio);
  74                         c->ref_count++;
  75                         return;
  76                 }
  77         }
  78
  79
  80         for(i = 0; i < h->len; i++) {
  81                 c = &g_array_index(h, LttvHookClosure, i);
  82                 if(new_c.prio < c->prio) {
  83                         g_array_insert_val(h,i,new_c);
  84                         return;
  85                 }
  86         }
  87         if(i == h->len)
  88                 g_array_append_val(h,new_c);
  89 }
  90
  91 /* lttv_hooks_add_list
  92  *
  93  * Adds a sorted list into another sorted list.
  94  *
  95  * Note : h->len is modified, but only incremented. This assures
  96  * its coherence through the function.
  97  *
  98  * j is an index to the element following the last one added in the
  99  * destination array.
 100  */
 101 void lttv_hooks_add_list(LttvHooks *h, const LttvHooks *list)
 102 {
 103         guint i,j,k;
 104         LttvHookClosure *c;
 105         const LttvHookClosure *new_c;
 106
 107         if(unlikely(list == NULL)) return;
 108
 109         for(i = 0, j = 0 ; i < list->len; i++) {
 110                 new_c = &g_array_index(list, LttvHookClosure, i);
 111                 gboolean found=FALSE;
 112
 113                 /* Preliminary check for duplication */
 114                 /* only hook and hook data is checked, not priority */
 115                 for(k = 0; k < h->len; k++) {
 116                         c = &g_array_index(h, LttvHookClosure, k);
 117                         if(new_c->hook == c->hook && new_c->hook_data == c->hook_data) {
 118                                 /* Found another identical entry : increment its ref_count and
 119                                  * jump over the source index */
 120                                 g_assert(new_c->prio == c->prio);
 121                                 found=TRUE;
 122                                 c->ref_count++;
 123                                 break;
 124                         }
 125                 }
 126
 127                 if(!found) {
 128                         /* If not found, add it to the destination array */
 129                         while(j < h->len) {
 130                                 c = &g_array_index(h, LttvHookClosure, j);
 131                                 if(new_c->prio < c->prio) {
 132                                         g_array_insert_val(h,j,*new_c);
 133                                         j++;
 134                                         break;
 135                                 }
 136                                 else j++;
 137                         }
 138                         if(j == h->len) {
 139                                 g_array_append_val(h,*new_c);
 140                                 j++;
 141                         }
 142                 }
 143         }
 144 }
 145
 146
 147 void *lttv_hooks_remove(LttvHooks *h, LttvHook f)
 148 {
 149         unsigned i;
 150
 151         void *hook_data;
 152
 153         LttvHookClosure *c;
 154
 155         for(i = 0 ; i < h->len ; i++) {
 156                 c = &g_array_index(h, LttvHookClosure, i);
 157                 if(c->hook == f) {
 158                         if(c->ref_count == 1) {
 159                                 hook_data = c->hook_data;
 160                                 lttv_hooks_remove_by_position(h, i);
 161                                 return hook_data;
 162                         } else {
 163                                 g_assert(c->ref_count != 0);
 164                                 c->ref_count--;
 165                                 return NULL;  /* We do not want anyone to free a hook_data
 166                                                                  still referenced */
 167                         }
 168                 }
 169         }
 170         return NULL;
 171 }
 172
 173
 174 void lttv_hooks_remove_data(LttvHooks *h, LttvHook f, void *hook_data)
 175 {
 176         unsigned i;
 177
 178         LttvHookClosure *c;
 179
 180         for(i = 0 ; i < h->len ; i++) {
 181                 c = &g_array_index(h, LttvHookClosure, i);
 182                 if(c->hook == f && c->hook_data == hook_data) {
 183                         if(c->ref_count == 1) {
 184                                 lttv_hooks_remove_by_position(h, i);
 185                                 return;
 186                         } else {
 187                                 g_assert(c->ref_count != 0);
 188                                 c->ref_count--;
 189                                 return;
 190                         }
 191                 }
 192         }
 193 }
 194
 195
 196 void lttv_hooks_remove_list(LttvHooks *h, LttvHooks *list)
 197 {
 198         guint i, j;
 199
 200         LttvHookClosure *c, *c_list;
 201
 202         if(list == NULL) return;
 203         for(i = 0, j = 0 ; i < h->len && j < list->len ;) {
 204                 c = &g_array_index(h, LttvHookClosure, i);
 205                 c_list = &g_array_index(list, LttvHookClosure, j);
 206                 if(c->hook == c_list->hook && c->hook_data == c_list->hook_data) {
 207                         if(c->ref_count == 1) {
 208                                 lttv_hooks_remove_by_position(h, i);
 209                         } else {
 210                                 g_assert(c->ref_count != 0);
 211                                 c->ref_count--;
 212                         }
 213                         j++;
 214                 }
 215                 else i++;
 216         }
 217
 218         /* Normally the hooks in h are ordered as in list. If this is not the case,
 219            try harder here. */
 220
 221         if(unlikely(j < list->len)) {
 222                 for(; j < list->len ; j++) {
 223                         c_list = &g_array_index(list, LttvHookClosure, j);
 224                         lttv_hooks_remove_data(h, c_list->hook, c_list->hook_data);
 225                 }
 226         }
 227 }
 228
 229
 230 unsigned lttv_hooks_number(LttvHooks *h)
 231 {
 232         return h->len;
 233 }
 234
 235
 236 void lttv_hooks_get(LttvHooks *h, unsigned i, LttvHook *f, void **hook_data,
 237                 LttvHookPrio *p)
 238 {
 239         LttvHookClosure *c;
 240
 241         if(unlikely(i >= h->len))
 242         {
 243                 *f = NULL;
 244                 *hook_data = NULL;
 245                 *p = 0;
 246                 return;
 247         }
 248
 249         c = &g_array_index(h, LttvHookClosure, i);
 250         *f = c->hook;
 251         *hook_data = c->hook_data;
 252         *p = c->prio;
 253 }
 254
 255
 256 void lttv_hooks_remove_by_position(LttvHooks *h, unsigned i)
 257 {
 258         g_array_remove_index(h, i);
 259 }
 260
 261 gboolean lttv_hooks_call(LttvHooks *h, void *call_data)
 262 {
 263         gboolean ret, sum_ret = FALSE;
 264
 265         LttvHookClosure *c;
 266
 267         guint i;
 268
 269         if(likely(h != NULL)) {
 270                 for(i = 0 ; i < h->len ; i++) {
 271                         c = &g_array_index(h, LttvHookClosure, i);
 272                         ret = c->hook(c->hook_data,call_data);
 273                         sum_ret = sum_ret || ret;
 274                 }
 275         }
 276         return sum_ret;
 277 }
 278
 279
 280 gboolean lttv_hooks_call_check(LttvHooks *h, void *call_data)
 281 {
 282         LttvHookClosure *c;
 283
 284         guint i;
 285
 286         for(i = 0 ; i < h->len ; i++) {
 287                 c = &g_array_index(h, LttvHookClosure, i);
 288                 if(unlikely(c->hook(c->hook_data,call_data))) return TRUE;
 289         }
 290         return FALSE;
 291 }
 292
 293 /* Optimised for h1 == NULL, h2 != NULL. This is the case
 294  * for optimised computation (with specific by id hooks, but
 295  * no main hooks).
 296  *
 297  * The second case that should occur the most often is
 298  * h1 != NULL , h2 == NULL.
 299  */
 300 gint lttv_hooks_call_merge(LttvHooks *h1, void *call_data1,
 301                 LttvHooks *h2, void *call_data2)
 302 {
 303         gint ret, sum_ret = 0;
 304
 305         LttvHookClosure *c1, *c2;
 306
 307         guint i, j;
 308
 309         if(unlikely(h1 != NULL)) {
 310                 if(unlikely(h2 != NULL)) {
 311                         for(i = 0, j = 0 ; i < h1->len && j < h2->len ;) {
 312                                 c1 = &g_array_index(h1, LttvHookClosure, i);
 313                                 c2 = &g_array_index(h2, LttvHookClosure, j);
 314                                 if(c1->prio <= c2->prio) {
 315                                         ret = c1->hook(c1->hook_data,call_data1);
 316                                         sum_ret = sum_ret | ret;
 317                                         i++;
 318                                 } else {
 319                                         ret = c2->hook(c2->hook_data,call_data2);
 320                                         sum_ret = sum_ret | ret;
 321                                         j++;
 322                                 }
 323                         }
 324                         /* Finish the last list with hooks left */
 325                         for(;i < h1->len; i++) {
 326                                 c1 = &g_array_index(h1, LttvHookClosure, i);
 327                                 ret = c1->hook(c1->hook_data,call_data1);
 328                                 sum_ret = sum_ret | ret;
 329                         }
 330                         for(;j < h2->len; j++) {
 331                                 c2 = &g_array_index(h2, LttvHookClosure, j);
 332                                 ret = c2->hook(c2->hook_data,call_data2);
 333                                 sum_ret = sum_ret | ret;
 334                         }
 335                 } else {  /* h1 != NULL && h2 == NULL */
 336                         for(i = 0 ; i < h1->len ; i++) {
 337                                 c1 = &g_array_index(h1, LttvHookClosure, i);
 338                                 ret = c1->hook(c1->hook_data,call_data1);
 339                                 sum_ret = sum_ret | ret;
 340                         }
 341                 }
 342         } else if(likely(h2 != NULL)) { /* h1 == NULL && h2 != NULL */
 343                  for(j = 0 ; j < h2->len ; j++) {
 344                         c2 = &g_array_index(h2, LttvHookClosure, j);
 345                         ret = c2->hook(c2->hook_data,call_data2);
 346                         sum_ret = sum_ret | ret;
 347                 }
 348         }
 349
 350         return sum_ret;
 351 }
 352
 353 gboolean lttv_hooks_call_check_merge(LttvHooks *h1, void *call_data1,
 354                 LttvHooks *h2, void *call_data2)
 355 {
 356         LttvHookClosure *c1, *c2;
 357
 358         guint i, j;
 359
 360         if(unlikely(h1 != NULL)) {
 361                 if(unlikely(h2 != NULL)) {
 362                         for(i = 0, j = 0 ; i < h1->len && j < h2->len ;) {
 363                                 c1 = &g_array_index(h1, LttvHookClosure, i);
 364                                 c2 = &g_array_index(h2, LttvHookClosure, j);
 365                                 if(c1->prio <= c2->prio) {
 366                                         if(c1->hook(c1->hook_data,call_data1)) return TRUE;
 367                                         i++;
 368                                 } else {
 369                                         if(c2->hook(c2->hook_data,call_data2)) return TRUE;
 370                                         j++;
 371                                 }
 372                         }
 373                         /* Finish the last list with hooks left */
 374                         for(;i < h1->len; i++) {
 375                                 c1 = &g_array_index(h1, LttvHookClosure, i);
 376                                 if(c1->hook(c1->hook_data,call_data1)) return TRUE;
 377                         }
 378                         for(;j < h2->len; j++) {
 379                                 c2 = &g_array_index(h2, LttvHookClosure, j);
 380                                 if(c2->hook(c2->hook_data,call_data2)) return TRUE;
 381                         }
 382                 } else { /* h2 == NULL && h1 != NULL */
 383                         for(i = 0 ; i < h1->len ; i++) {
 384                                 c1 = &g_array_index(h1, LttvHookClosure, i);
 385                                 if(c1->hook(c1->hook_data,call_data1)) return TRUE;
 386                         }
 387                 }
 388         } else if(likely(h2 != NULL)) { /* h1 == NULL && h2 != NULL */
 389                 for(j = 0 ; j < h2->len ; j++) {
 390                         c2 = &g_array_index(h2, LttvHookClosure, j);
 391                         if(c2->hook(c2->hook_data,call_data2)) return TRUE;
 392                 }
 393         }
 394
 395         return FALSE;
 396 }