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 ptid_t
 125 thread_to_gdb_id (struct thread_info *thread)
 126 {
 127   return thread->entry.id;
 128 }
 129
 130 /* Wrapper around get_first_inferior to return a struct thread_info *.  */
 131
 132 struct thread_info *
 133 get_first_thread (void)
 134 {
 135   return (struct thread_info *) get_first_inferior (&all_threads);
 136 }
 137
 138 struct thread_info *
 139 find_thread_ptid (ptid_t ptid)
 140 {
 141   return (struct thread_info *) find_inferior_id (&all_threads, ptid);
 142 }
 143
 144 /* Find a thread associated with the given PROCESS, or NULL if no
 145    such thread exists.  */
 146
 147 static struct thread_info *
 148 find_thread_process (const struct process_info *const process)
 149 {
 150   return find_any_thread_of_pid (process->entry.id.pid ());
 151 }
 152
 153 /* Helper for find_any_thread_of_pid.  Returns true if a thread
 154    matches a PID.  */
 155
 156 static int
 157 thread_of_pid (struct inferior_list_entry *entry, void *pid_p)
 158 {
 159   int pid = *(int *) pid_p;
 160
 161   return (ptid_get_pid (entry->id) == pid);
 162 }
 163
 164 /* See gdbthread.h.  */
 165
 166 struct thread_info *
 167 find_any_thread_of_pid (int pid)
 168 {
 169   struct inferior_list_entry *entry;
 170
 171   entry = find_inferior (&all_threads, thread_of_pid, &pid);
 172
 173   return (struct thread_info *) entry;
 174 }
 175
 176 static void
 177 free_one_thread (struct inferior_list_entry *inf)
 178 {
 179   struct thread_info *thread = get_thread (inf);
 180   free_register_cache (thread_regcache_data (thread));
 181   free (thread);
 182 }
 183
 184 void
 185 remove_thread (struct thread_info *thread)
 186 {
 187   if (thread->btrace != NULL)
 188     target_disable_btrace (thread->btrace);
 189
 190   discard_queued_stop_replies (ptid_of (thread));
 191   remove_inferior (&all_threads, (struct inferior_list_entry *) thread);
 192   free_one_thread (&thread->entry);
 193   if (current_thread == thread)
 194     current_thread = NULL;
 195 }
 196
 197 /* Return a pointer to the first inferior in LIST, or NULL if there isn't one.
 198    This is for cases where the caller needs a thread, but doesn't care
 199    which one.  */
 200
 201 struct inferior_list_entry *
 202 get_first_inferior (struct inferior_list *list)
 203 {
 204   if (list->head != NULL)
 205     return list->head;
 206   return NULL;
 207 }
 208
 209 /* Find the first inferior_list_entry E in LIST for which FUNC (E, ARG)
 210    returns non-zero.  If no entry is found then return NULL.  */
 211
 212 struct inferior_list_entry *
 213 find_inferior (struct inferior_list *list,
 214                int (*func) (struct inferior_list_entry *, void *), void *arg)
 215 {
 216   struct inferior_list_entry *inf = list->head;
 217
 218   while (inf != NULL)
 219     {
 220       struct inferior_list_entry *next;
 221
 222       next = inf->next;
 223       if ((*func) (inf, arg))
 224         return inf;
 225       inf = next;
 226     }
 227
 228   return NULL;
 229 }
 230
 231 /* Find the random inferior_list_entry E in LIST for which FUNC (E, ARG)
 232    returns non-zero.  If no entry is found then return NULL.  */
 233
 234 struct inferior_list_entry *
 235 find_inferior_in_random (struct inferior_list *list,
 236                          int (*func) (struct inferior_list_entry *, void *),
 237                          void *arg)
 238 {
 239   struct inferior_list_entry *inf = list->head;
 240   int count = 0;
 241   int random_selector;
 242
 243   /* First count how many interesting entries we have.  */
 244   while (inf != NULL)
 245     {
 246       struct inferior_list_entry *next;
 247
 248       next = inf->next;
 249       if ((*func) (inf, arg))
 250         count++;
 251       inf = next;
 252     }
 253
 254   if (count == 0)
 255     return NULL;
 256
 257   /* Now randomly pick an entry out of those.  */
 258   random_selector = (int)
 259     ((count * (double) rand ()) / (RAND_MAX + 1.0));
 260
 261   inf = list->head;
 262   while (inf != NULL)
 263     {
 264       struct inferior_list_entry *next;
 265
 266       next = inf->next;
 267       if ((*func) (inf, arg) && (random_selector-- == 0))
 268         return inf;
 269       inf = next;
 270     }
 271
 272   gdb_assert_not_reached ("failed to find an inferior in random.");
 273   return NULL;
 274 }
 275
 276 struct inferior_list_entry *
 277 find_inferior_id (struct inferior_list *list, ptid_t id)
 278 {
 279   struct inferior_list_entry *inf = list->head;
 280
 281   while (inf != NULL)
 282     {
 283       if (ptid_equal (inf->id, id))
 284         return inf;
 285       inf = inf->next;
 286     }
 287
 288   return NULL;
 289 }
 290
 291 void *
 292 thread_target_data (struct thread_info *thread)
 293 {
 294   return thread->target_data;
 295 }
 296
 297 struct regcache *
 298 thread_regcache_data (struct thread_info *thread)
 299 {
 300   return thread->regcache_data;
 301 }
 302
 303 void
 304 set_thread_regcache_data (struct thread_info *thread, struct regcache *data)
 305 {
 306   thread->regcache_data = data;
 307 }
 308
 309 /* Return true if LIST has exactly one entry.  */
 310
 311 int
 312 one_inferior_p (struct inferior_list *list)
 313 {
 314   return list->head != NULL && list->head == list->tail;
 315 }
 316
 317 /* Reset head,tail of LIST, assuming all entries have already been freed.  */
 318
 319 void
 320 clear_inferior_list (struct inferior_list *list)
 321 {
 322   list->head = NULL;
 323   list->tail = NULL;
 324 }
 325
 326 void
 327 clear_inferiors (void)
 328 {
 329   for_each_inferior (&all_threads, free_one_thread);
 330   clear_inferior_list (&all_threads);
 331
 332   clear_dlls ();
 333
 334   current_thread = NULL;
 335 }
 336
 337 struct process_info *
 338 add_process (int pid, int attached)
 339 {
 340   struct process_info *process = XCNEW (struct process_info);
 341
 342   process->entry.id = pid_to_ptid (pid);
 343   process->attached = attached;
 344
 345   add_inferior_to_list (&all_processes, &process->entry);
 346
 347   return process;
 348 }
 349
 350 /* Remove a process from the common process list and free the memory
 351    allocated for it.
 352    The caller is responsible for freeing private data first.  */
 353
 354 void
 355 remove_process (struct process_info *process)
 356 {
 357   clear_symbol_cache (&process->symbol_cache);
 358   free_all_breakpoints (process);
 359   gdb_assert (find_thread_process (process) == NULL);
 360   remove_inferior (&all_processes, &process->entry);
 361   VEC_free (int, process->syscalls_to_catch);
 362   free (process);
 363 }
 364
 365 struct process_info *
 366 find_process_pid (int pid)
 367 {
 368   return (struct process_info *)
 369     find_inferior_id (&all_processes, pid_to_ptid (pid));
 370 }
 371
 372 /* Wrapper around get_first_inferior to return a struct process_info *.  */
 373
 374 struct process_info *
 375 get_first_process (void)
 376 {
 377   return (struct process_info *) get_first_inferior (&all_processes);
 378 }
 379
 380 /* Return non-zero if INF, a struct process_info, was started by us,
 381    i.e. not attached to.  */
 382
 383 static int
 384 started_inferior_callback (struct inferior_list_entry *entry, void *args)
 385 {
 386   struct process_info *process = (struct process_info *) entry;
 387
 388   return ! process->attached;
 389 }
 390
 391 /* Return non-zero if there are any inferiors that we have created
 392    (as opposed to attached-to).  */
 393
 394 int
 395 have_started_inferiors_p (void)
 396 {
 397   return (find_inferior (&all_processes, started_inferior_callback, NULL)
 398           != NULL);
 399 }
 400
 401 /* Return non-zero if INF, a struct process_info, was attached to.  */
 402
 403 static int
 404 attached_inferior_callback (struct inferior_list_entry *entry, void *args)
 405 {
 406   struct process_info *process = (struct process_info *) entry;
 407
 408   return process->attached;
 409 }
 410
 411 /* Return non-zero if there are any inferiors that we have attached to.  */
 412
 413 int
 414 have_attached_inferiors_p (void)
 415 {
 416   return (find_inferior (&all_processes, attached_inferior_callback, NULL)
 417           != NULL);
 418 }
 419
 420 struct process_info *
 421 get_thread_process (const struct thread_info *thread)
 422 {
 423   int pid = ptid_get_pid (thread->entry.id);
 424   return find_process_pid (pid);
 425 }
 426
 427 struct process_info *
 428 current_process (void)
 429 {
 430   gdb_assert (current_thread != NULL);
 431   return get_thread_process (current_thread);
 432 }
 433
 434 static void
 435 do_restore_current_thread_cleanup (void *arg)
 436 {
 437   current_thread = (struct thread_info *) arg;
 438 }
 439
 440 struct cleanup *
 441 make_cleanup_restore_current_thread (void)
 442 {
 443   return make_cleanup (do_restore_current_thread_cleanup, current_thread);
 444 }
 445
 446 /* See common/common-gdbthread.h.  */
 447
 448 void
 449 switch_to_thread (ptid_t ptid)
 450 {
 451   if (!ptid_equal (ptid, minus_one_ptid))
 452     current_thread = find_thread_ptid (ptid);
 453 }