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 std::list<process_info *> 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 /* The current working directory used to start the inferior.  */
  33 static const char *current_inferior_cwd = NULL;
  34
  35 void
  36 add_inferior_to_list (struct inferior_list *list,
  37                       struct inferior_list_entry *new_inferior)
  38 {
  39   new_inferior->next = NULL;
  40   if (list->tail != NULL)
  41     list->tail->next = new_inferior;
  42   else
  43     list->head = new_inferior;
  44   list->tail = new_inferior;
  45 }
  46
  47 /* Invoke ACTION for each inferior in LIST.  */
  48
  49 void
  50 for_each_inferior (struct inferior_list *list,
  51                    void (*action) (struct inferior_list_entry *))
  52 {
  53   struct inferior_list_entry *cur = list->head, *next;
  54
  55   while (cur != NULL)
  56     {
  57       next = cur->next;
  58       (*action) (cur);
  59       cur = next;
  60     }
  61 }
  62
  63 /* Invoke ACTION for each inferior in LIST, passing DATA to ACTION.  */
  64
  65 void
  66 for_each_inferior_with_data (struct inferior_list *list,
  67                              void (*action) (struct inferior_list_entry *,
  68                                              void *),
  69                              void *data)
  70 {
  71   struct inferior_list_entry *cur = list->head, *next;
  72
  73   while (cur != NULL)
  74     {
  75       next = cur->next;
  76       (*action) (cur, data);
  77       cur = next;
  78     }
  79 }
  80
  81 void
  82 remove_inferior (struct inferior_list *list,
  83                  struct inferior_list_entry *entry)
  84 {
  85   struct inferior_list_entry **cur;
  86
  87   if (list->head == entry)
  88     {
  89       list->head = entry->next;
  90       if (list->tail == entry)
  91         list->tail = list->head;
  92       return;
  93     }
  94
  95   cur = &list->head;
  96   while (*cur && (*cur)->next != entry)
  97     cur = &(*cur)->next;
  98
  99   if (*cur == NULL)
 100     return;
 101
 102   (*cur)->next = entry->next;
 103
 104   if (list->tail == entry)
 105     list->tail = *cur;
 106 }
 107
 108 struct thread_info *
 109 add_thread (ptid_t thread_id, void *target_data)
 110 {
 111   struct thread_info *new_thread = XCNEW (struct thread_info);
 112
 113   new_thread->entry.id = thread_id;
 114   new_thread->last_resume_kind = resume_continue;
 115   new_thread->last_status.kind = TARGET_WAITKIND_IGNORE;
 116
 117   add_inferior_to_list (&all_threads, &new_thread->entry);
 118
 119   if (current_thread == NULL)
 120     current_thread = new_thread;
 121
 122   new_thread->target_data = target_data;
 123
 124   return new_thread;
 125 }
 126
 127 /* Wrapper around get_first_inferior to return a struct thread_info *.  */
 128
 129 struct thread_info *
 130 get_first_thread (void)
 131 {
 132   return (struct thread_info *) get_first_inferior (&all_threads);
 133 }
 134
 135 struct thread_info *
 136 find_thread_ptid (ptid_t ptid)
 137 {
 138   return (struct thread_info *) find_inferior_id (&all_threads, ptid);
 139 }
 140
 141 /* Find a thread associated with the given PROCESS, or NULL if no
 142    such thread exists.  */
 143
 144 static struct thread_info *
 145 find_thread_process (const struct process_info *const process)
 146 {
 147   return find_any_thread_of_pid (process->pid);
 148 }
 149
 150 /* Helper for find_any_thread_of_pid.  Returns true if a thread
 151    matches a PID.  */
 152
 153 static int
 154 thread_of_pid (struct inferior_list_entry *entry, void *pid_p)
 155 {
 156   int pid = *(int *) pid_p;
 157
 158   return (ptid_get_pid (entry->id) == pid);
 159 }
 160
 161 /* See gdbthread.h.  */
 162
 163 struct thread_info *
 164 find_any_thread_of_pid (int pid)
 165 {
 166   struct inferior_list_entry *entry;
 167
 168   entry = find_inferior (&all_threads, thread_of_pid, &pid);
 169
 170   return (struct thread_info *) entry;
 171 }
 172
 173 static void
 174 free_one_thread (struct inferior_list_entry *inf)
 175 {
 176   struct thread_info *thread = get_thread (inf);
 177   free_register_cache (thread_regcache_data (thread));
 178   free (thread);
 179 }
 180
 181 void
 182 remove_thread (struct thread_info *thread)
 183 {
 184   if (thread->btrace != NULL)
 185     target_disable_btrace (thread->btrace);
 186
 187   discard_queued_stop_replies (ptid_of (thread));
 188   remove_inferior (&all_threads, (struct inferior_list_entry *) thread);
 189   free_one_thread (&thread->entry);
 190   if (current_thread == thread)
 191     current_thread = NULL;
 192 }
 193
 194 /* Return a pointer to the first inferior in LIST, or NULL if there isn't one.
 195    This is for cases where the caller needs a thread, but doesn't care
 196    which one.  */
 197
 198 struct inferior_list_entry *
 199 get_first_inferior (struct inferior_list *list)
 200 {
 201   if (list->head != NULL)
 202     return list->head;
 203   return NULL;
 204 }
 205
 206 /* Find the first inferior_list_entry E in LIST for which FUNC (E, ARG)
 207    returns non-zero.  If no entry is found then return NULL.  */
 208
 209 struct inferior_list_entry *
 210 find_inferior (struct inferior_list *list,
 211                int (*func) (struct inferior_list_entry *, void *), void *arg)
 212 {
 213   struct inferior_list_entry *inf = list->head;
 214
 215   while (inf != NULL)
 216     {
 217       struct inferior_list_entry *next;
 218
 219       next = inf->next;
 220       if ((*func) (inf, arg))
 221         return inf;
 222       inf = next;
 223     }
 224
 225   return NULL;
 226 }
 227
 228 /* Find the random inferior_list_entry E in LIST for which FUNC (E, ARG)
 229    returns non-zero.  If no entry is found then return NULL.  */
 230
 231 struct inferior_list_entry *
 232 find_inferior_in_random (struct inferior_list *list,
 233                          int (*func) (struct inferior_list_entry *, void *),
 234                          void *arg)
 235 {
 236   struct inferior_list_entry *inf = list->head;
 237   int count = 0;
 238   int random_selector;
 239
 240   /* First count how many interesting entries we have.  */
 241   while (inf != NULL)
 242     {
 243       struct inferior_list_entry *next;
 244
 245       next = inf->next;
 246       if ((*func) (inf, arg))
 247         count++;
 248       inf = next;
 249     }
 250
 251   if (count == 0)
 252     return NULL;
 253
 254   /* Now randomly pick an entry out of those.  */
 255   random_selector = (int)
 256     ((count * (double) rand ()) / (RAND_MAX + 1.0));
 257
 258   inf = list->head;
 259   while (inf != NULL)
 260     {
 261       struct inferior_list_entry *next;
 262
 263       next = inf->next;
 264       if ((*func) (inf, arg) && (random_selector-- == 0))
 265         return inf;
 266       inf = next;
 267     }
 268
 269   gdb_assert_not_reached ("failed to find an inferior in random.");
 270   return NULL;
 271 }
 272
 273 struct inferior_list_entry *
 274 find_inferior_id (struct inferior_list *list, ptid_t id)
 275 {
 276   struct inferior_list_entry *inf = list->head;
 277
 278   while (inf != NULL)
 279     {
 280       if (ptid_equal (inf->id, id))
 281         return inf;
 282       inf = inf->next;
 283     }
 284
 285   return NULL;
 286 }
 287
 288 void *
 289 thread_target_data (struct thread_info *thread)
 290 {
 291   return thread->target_data;
 292 }
 293
 294 struct regcache *
 295 thread_regcache_data (struct thread_info *thread)
 296 {
 297   return thread->regcache_data;
 298 }
 299
 300 void
 301 set_thread_regcache_data (struct thread_info *thread, struct regcache *data)
 302 {
 303   thread->regcache_data = data;
 304 }
 305
 306 /* Return true if LIST has exactly one entry.  */
 307
 308 int
 309 one_inferior_p (struct inferior_list *list)
 310 {
 311   return list->head != NULL && list->head == list->tail;
 312 }
 313
 314 /* Reset head,tail of LIST, assuming all entries have already been freed.  */
 315
 316 void
 317 clear_inferior_list (struct inferior_list *list)
 318 {
 319   list->head = NULL;
 320   list->tail = NULL;
 321 }
 322
 323 void
 324 clear_inferiors (void)
 325 {
 326   for_each_inferior (&all_threads, free_one_thread);
 327   clear_inferior_list (&all_threads);
 328
 329   clear_dlls ();
 330
 331   current_thread = NULL;
 332 }
 333
 334 struct process_info *
 335 add_process (int pid, int attached)
 336 {
 337   struct process_info *process = XCNEW (struct process_info);
 338
 339   process->pid = pid;
 340   process->attached = attached;
 341
 342   all_processes.push_back (process);
 343
 344   return process;
 345 }
 346
 347 /* Remove a process from the common process list and free the memory
 348    allocated for it.
 349    The caller is responsible for freeing private data first.  */
 350
 351 void
 352 remove_process (struct process_info *process)
 353 {
 354   clear_symbol_cache (&process->symbol_cache);
 355   free_all_breakpoints (process);
 356   gdb_assert (find_thread_process (process) == NULL);
 357   all_processes.remove (process);
 358   VEC_free (int, process->syscalls_to_catch);
 359   free (process);
 360 }
 361
 362 process_info *
 363 find_process_pid (int pid)
 364 {
 365   return find_process ([&] (process_info *process) {
 366     return process->pid == pid;
 367   });
 368 }
 369
 370 /* Get the first process in the process list, or NULL if the list is empty.  */
 371
 372 process_info *
 373 get_first_process (void)
 374 {
 375   if (!all_processes.empty ())
 376     return all_processes.front ();
 377   else
 378     return NULL;
 379 }
 380
 381 /* Return non-zero if there are any inferiors that we have created
 382    (as opposed to attached-to).  */
 383
 384 int
 385 have_started_inferiors_p (void)
 386 {
 387   return find_process ([] (process_info *process) {
 388     return !process->attached;
 389   }) != NULL;
 390 }
 391
 392 /* Return non-zero if there are any inferiors that we have attached to.  */
 393
 394 int
 395 have_attached_inferiors_p (void)
 396 {
 397   return find_process ([] (process_info *process) {
 398     return process->attached;
 399   }) != NULL;
 400 }
 401
 402 struct process_info *
 403 get_thread_process (const struct thread_info *thread)
 404 {
 405   int pid = ptid_get_pid (thread->entry.id);
 406   return find_process_pid (pid);
 407 }
 408
 409 struct process_info *
 410 current_process (void)
 411 {
 412   gdb_assert (current_thread != NULL);
 413   return get_thread_process (current_thread);
 414 }
 415
 416 static void
 417 do_restore_current_thread_cleanup (void *arg)
 418 {
 419   current_thread = (struct thread_info *) arg;
 420 }
 421
 422 struct cleanup *
 423 make_cleanup_restore_current_thread (void)
 424 {
 425   return make_cleanup (do_restore_current_thread_cleanup, current_thread);
 426 }
 427
 428 /* See common/common-gdbthread.h.  */
 429
 430 void
 431 switch_to_thread (ptid_t ptid)
 432 {
 433   gdb_assert (ptid != minus_one_ptid);
 434   current_thread = find_thread_ptid (ptid);
 435 }
 436
 437 /* See common/common-inferior.h.  */
 438
 439 const char *
 440 get_inferior_cwd ()
 441 {
 442   return current_inferior_cwd;
 443 }
 444
 445 /* See common/common-inferior.h.  */
 446
 447 void
 448 set_inferior_cwd (const char *cwd)
 449 {
 450   xfree ((void *) current_inferior_cwd);
 451   if (cwd != NULL)
 452     current_inferior_cwd = xstrdup (cwd);
 453   else
 454     current_inferior_cwd = NULL;
 455 }