gdb/gdbserver/inferiors.c

   1 /* Inferior process information for the remote server for GDB.
   2    Copyright (C) 2002-2017 Free Software Foundation, Inc.
   3
   4    Contributed by MontaVista Software.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "server.h"
  22 #include "gdbthread.h"
  23 #include "dll.h"
  24
  25 struct inferior_list all_processes;
  26 struct inferior_list all_threads;
  27
  28 struct thread_info *current_thread;
  29
  30 #define get_thread(inf) ((struct thread_info *)(inf))
  31
  32 void
  33 add_inferior_to_list (struct inferior_list *list,
  34                       struct inferior_list_entry *new_inferior)
  35 {
  36   new_inferior->next = NULL;
  37   if (list->tail != NULL)
  38     list->tail->next = new_inferior;
  39   else
  40     list->head = new_inferior;
  41   list->tail = new_inferior;
  42 }
  43
  44 /* Invoke ACTION for each inferior in LIST.  */
  45
  46 void
  47 for_each_inferior (struct inferior_list *list,
  48                    void (*action) (struct inferior_list_entry *))
  49 {
  50   struct inferior_list_entry *cur = list->head, *next;
  51
  52   while (cur != NULL)
  53     {
  54       next = cur->next;
  55       (*action) (cur);
  56       cur = next;
  57     }
  58 }
  59
  60 /* Invoke ACTION for each inferior in LIST, passing DATA to ACTION.  */
  61
  62 void
  63 for_each_inferior_with_data (struct inferior_list *list,
  64                              void (*action) (struct inferior_list_entry *,
  65                                              void *),
  66                              void *data)
  67 {
  68   struct inferior_list_entry *cur = list->head, *next;
  69
  70   while (cur != NULL)
  71     {
  72       next = cur->next;
  73       (*action) (cur, data);
  74       cur = next;
  75     }
  76 }
  77
  78 void
  79 remove_inferior (struct inferior_list *list,
  80                  struct inferior_list_entry *entry)
  81 {
  82   struct inferior_list_entry **cur;
  83
  84   if (list->head == entry)
  85     {
  86       list->head = entry->next;
  87       if (list->tail == entry)
  88         list->tail = list->head;
  89       return;
  90     }
  91
  92   cur = &list->head;
  93   while (*cur && (*cur)->next != entry)
  94     cur = &(*cur)->next;
  95
  96   if (*cur == NULL)
  97     return;
  98
  99   (*cur)->next = entry->next;
 100
 101   if (list->tail == entry)
 102     list->tail = *cur;
 103 }
 104
 105 struct thread_info *
 106 add_thread (ptid_t thread_id, void *target_data)
 107 {
 108   struct thread_info *new_thread = XCNEW (struct thread_info);
 109
 110   new_thread->entry.id = thread_id;
 111   new_thread->last_resume_kind = resume_continue;
 112   new_thread->last_status.kind = TARGET_WAITKIND_IGNORE;
 113
 114   add_inferior_to_list (&all_threads, &new_thread->entry);
 115
 116   if (current_thread == NULL)
 117     current_thread = new_thread;
 118
 119   new_thread->target_data = target_data;
 120
 121   return new_thread;
 122 }
 123
 124 /* Wrapper around get_first_inferior to return a struct thread_info *.  */
 125
 126 struct thread_info *
 127 get_first_thread (void)
 128 {
 129   return (struct thread_info *) get_first_inferior (&all_threads);
 130 }
 131
 132 struct thread_info *
 133 find_thread_ptid (ptid_t ptid)
 134 {
 135   return (struct thread_info *) find_inferior_id (&all_threads, ptid);
 136 }
 137
 138 /* Find a thread associated with the given PROCESS, or NULL if no
 139    such thread exists.  */
 140
 141 static struct thread_info *
 142 find_thread_process (const struct process_info *const process)
 143 {
 144   return find_any_thread_of_pid (process->entry.id.pid ());
 145 }
 146
 147 /* Helper for find_any_thread_of_pid.  Returns true if a thread
 148    matches a PID.  */
 149
 150 static int
 151 thread_of_pid (struct inferior_list_entry *entry, void *pid_p)
 152 {
 153   int pid = *(int *) pid_p;
 154
 155   return (ptid_get_pid (entry->id) == pid);
 156 }
 157
 158 /* See gdbthread.h.  */
 159
 160 struct thread_info *
 161 find_any_thread_of_pid (int pid)
 162 {
 163   struct inferior_list_entry *entry;
 164
 165   entry = find_inferior (&all_threads, thread_of_pid, &pid);
 166
 167   return (struct thread_info *) entry;
 168 }
 169
 170 static void
 171 free_one_thread (struct inferior_list_entry *inf)
 172 {
 173   struct thread_info *thread = get_thread (inf);
 174   free_register_cache (thread_regcache_data (thread));
 175   free (thread);
 176 }
 177
 178 void
 179 remove_thread (struct thread_info *thread)
 180 {
 181   if (thread->btrace != NULL)
 182     target_disable_btrace (thread->btrace);
 183
 184   discard_queued_stop_replies (ptid_of (thread));
 185   remove_inferior (&all_threads, (struct inferior_list_entry *) thread);
 186   free_one_thread (&thread->entry);
 187   if (current_thread == thread)
 188     current_thread = NULL;
 189 }
 190
 191 /* Return a pointer to the first inferior in LIST, or NULL if there isn't one.
 192    This is for cases where the caller needs a thread, but doesn't care
 193    which one.  */
 194
 195 struct inferior_list_entry *
 196 get_first_inferior (struct inferior_list *list)
 197 {
 198   if (list->head != NULL)
 199     return list->head;
 200   return NULL;
 201 }
 202
 203 /* Find the first inferior_list_entry E in LIST for which FUNC (E, ARG)
 204    returns non-zero.  If no entry is found then return NULL.  */
 205
 206 struct inferior_list_entry *
 207 find_inferior (struct inferior_list *list,
 208                int (*func) (struct inferior_list_entry *, void *), void *arg)
 209 {
 210   struct inferior_list_entry *inf = list->head;
 211
 212   while (inf != NULL)
 213     {
 214       struct inferior_list_entry *next;
 215
 216       next = inf->next;
 217       if ((*func) (inf, arg))
 218         return inf;
 219       inf = next;
 220     }
 221
 222   return NULL;
 223 }
 224
 225 /* Find the random inferior_list_entry E in LIST for which FUNC (E, ARG)
 226    returns non-zero.  If no entry is found then return NULL.  */
 227
 228 struct inferior_list_entry *
 229 find_inferior_in_random (struct inferior_list *list,
 230                          int (*func) (struct inferior_list_entry *, void *),
 231                          void *arg)
 232 {
 233   struct inferior_list_entry *inf = list->head;
 234   int count = 0;
 235   int random_selector;
 236
 237   /* First count how many interesting entries we have.  */
 238   while (inf != NULL)
 239     {
 240       struct inferior_list_entry *next;
 241
 242       next = inf->next;
 243       if ((*func) (inf, arg))
 244         count++;
 245       inf = next;
 246     }
 247
 248   if (count == 0)
 249     return NULL;
 250
 251   /* Now randomly pick an entry out of those.  */
 252   random_selector = (int)
 253     ((count * (double) rand ()) / (RAND_MAX + 1.0));
 254
 255   inf = list->head;
 256   while (inf != NULL)
 257     {
 258       struct inferior_list_entry *next;
 259
 260       next = inf->next;
 261       if ((*func) (inf, arg) && (random_selector-- == 0))
 262         return inf;
 263       inf = next;
 264     }
 265
 266   gdb_assert_not_reached ("failed to find an inferior in random.");
 267   return NULL;
 268 }
 269
 270 struct inferior_list_entry *
 271 find_inferior_id (struct inferior_list *list, ptid_t id)
 272 {
 273   struct inferior_list_entry *inf = list->head;
 274
 275   while (inf != NULL)
 276     {
 277       if (ptid_equal (inf->id, id))
 278         return inf;
 279       inf = inf->next;
 280     }
 281
 282   return NULL;
 283 }
 284
 285 void *
 286 thread_target_data (struct thread_info *thread)
 287 {
 288   return thread->target_data;
 289 }
 290
 291 struct regcache *
 292 thread_regcache_data (struct thread_info *thread)
 293 {
 294   return thread->regcache_data;
 295 }
 296
 297 void
 298 set_thread_regcache_data (struct thread_info *thread, struct regcache *data)
 299 {
 300   thread->regcache_data = data;
 301 }
 302
 303 /* Return true if LIST has exactly one entry.  */
 304
 305 int
 306 one_inferior_p (struct inferior_list *list)
 307 {
 308   return list->head != NULL && list->head == list->tail;
 309 }
 310
 311 /* Reset head,tail of LIST, assuming all entries have already been freed.  */
 312
 313 void
 314 clear_inferior_list (struct inferior_list *list)
 315 {
 316   list->head = NULL;
 317   list->tail = NULL;
 318 }
 319
 320 void
 321 clear_inferiors (void)
 322 {
 323   for_each_inferior (&all_threads, free_one_thread);
 324   clear_inferior_list (&all_threads);
 325
 326   clear_dlls ();
 327
 328   current_thread = NULL;
 329 }
 330
 331 struct process_info *
 332 add_process (int pid, int attached)
 333 {
 334   struct process_info *process = XCNEW (struct process_info);
 335
 336   process->entry.id = pid_to_ptid (pid);
 337   process->attached = attached;
 338
 339   add_inferior_to_list (&all_processes, &process->entry);
 340
 341   return process;
 342 }
 343
 344 /* Remove a process from the common process list and free the memory
 345    allocated for it.
 346    The caller is responsible for freeing private data first.  */
 347
 348 void
 349 remove_process (struct process_info *process)
 350 {
 351   clear_symbol_cache (&process->symbol_cache);
 352   free_all_breakpoints (process);
 353   gdb_assert (find_thread_process (process) == NULL);
 354   remove_inferior (&all_processes, &process->entry);
 355   VEC_free (int, process->syscalls_to_catch);
 356   free (process);
 357 }
 358
 359 struct process_info *
 360 find_process_pid (int pid)
 361 {
 362   return (struct process_info *)
 363     find_inferior_id (&all_processes, pid_to_ptid (pid));
 364 }
 365
 366 /* Wrapper around get_first_inferior to return a struct process_info *.  */
 367
 368 struct process_info *
 369 get_first_process (void)
 370 {
 371   return (struct process_info *) get_first_inferior (&all_processes);
 372 }
 373
 374 /* Return non-zero if INF, a struct process_info, was started by us,
 375    i.e. not attached to.  */
 376
 377 static int
 378 started_inferior_callback (struct inferior_list_entry *entry, void *args)
 379 {
 380   struct process_info *process = (struct process_info *) entry;
 381
 382   return ! process->attached;
 383 }
 384
 385 /* Return non-zero if there are any inferiors that we have created
 386    (as opposed to attached-to).  */
 387
 388 int
 389 have_started_inferiors_p (void)
 390 {
 391   return (find_inferior (&all_processes, started_inferior_callback, NULL)
 392           != NULL);
 393 }
 394
 395 /* Return non-zero if INF, a struct process_info, was attached to.  */
 396
 397 static int
 398 attached_inferior_callback (struct inferior_list_entry *entry, void *args)
 399 {
 400   struct process_info *process = (struct process_info *) entry;
 401
 402   return process->attached;
 403 }
 404
 405 /* Return non-zero if there are any inferiors that we have attached to.  */
 406
 407 int
 408 have_attached_inferiors_p (void)
 409 {
 410   return (find_inferior (&all_processes, attached_inferior_callback, NULL)
 411           != NULL);
 412 }
 413
 414 struct process_info *
 415 get_thread_process (const struct thread_info *thread)
 416 {
 417   int pid = ptid_get_pid (thread->entry.id);
 418   return find_process_pid (pid);
 419 }
 420
 421 struct process_info *
 422 current_process (void)
 423 {
 424   gdb_assert (current_thread != NULL);
 425   return get_thread_process (current_thread);
 426 }
 427
 428 static void
 429 do_restore_current_thread_cleanup (void *arg)
 430 {
 431   current_thread = (struct thread_info *) arg;
 432 }
 433
 434 struct cleanup *
 435 make_cleanup_restore_current_thread (void)
 436 {
 437   return make_cleanup (do_restore_current_thread_cleanup, current_thread);
 438 }
 439
 440 /* See common/common-gdbthread.h.  */
 441
 442 void
 443 switch_to_thread (ptid_t ptid)
 444 {
 445   if (!ptid_equal (ptid, minus_one_ptid))
 446     current_thread = find_thread_ptid (ptid);
 447 }