1 /* Multi-process/thread control defs for GDB, the GNU debugger. 2 Copyright (C) 1987-2013 Free Software Foundation, Inc. 3 Contributed by Lynx Real-Time Systems, Inc. Los Gatos, CA. 4 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 #ifndef GDBTHREAD_H 22 #define GDBTHREAD_H 23 24 struct symtab; 25 26 #include "breakpoint.h" 27 #include "frame.h" 28 #include "ui-out.h" 29 #include "inferior.h" 30 #include "btrace.h" 31 32 /* Frontend view of the thread state. Possible extensions: stepping, 33 finishing, until(ling),... */ 34 enum thread_state 35 { 36 THREAD_STOPPED, 37 THREAD_RUNNING, 38 THREAD_EXITED, 39 }; 40 41 /* Inferior thread specific part of `struct infcall_control_state'. 42 43 Inferior process counterpart is `struct inferior_control_state'. */ 44 45 struct thread_control_state 46 { 47 /* User/external stepping state. */ 48 49 /* Step-resume or longjmp-resume breakpoint. */ 50 struct breakpoint *step_resume_breakpoint; 51 52 /* Exception-resume breakpoint. */ 53 struct breakpoint *exception_resume_breakpoint; 54 55 /* Range to single step within. 56 57 If this is nonzero, respond to a single-step signal by continuing 58 to step if the pc is in this range. 59 60 If step_range_start and step_range_end are both 1, it means to 61 step for a single instruction (FIXME: it might clean up 62 wait_for_inferior in a minor way if this were changed to the 63 address of the instruction and that address plus one. But maybe 64 not). */ 65 CORE_ADDR step_range_start; /* Inclusive */ 66 CORE_ADDR step_range_end; /* Exclusive */ 67 68 /* Stack frame address as of when stepping command was issued. 69 This is how we know when we step into a subroutine call, and how 70 to set the frame for the breakpoint used to step out. */ 71 struct frame_id step_frame_id; 72 73 /* Similarly, the frame ID of the underlying stack frame (skipping 74 any inlined frames). */ 75 struct frame_id step_stack_frame_id; 76 77 /* Nonzero if we are presently stepping over a breakpoint. 78 79 If we hit a breakpoint or watchpoint, and then continue, we need 80 to single step the current thread with breakpoints disabled, to 81 avoid hitting the same breakpoint or watchpoint again. And we 82 should step just a single thread and keep other threads stopped, 83 so that other threads don't miss breakpoints while they are 84 removed. 85 86 So, this variable simultaneously means that we need to single 87 step the current thread, keep other threads stopped, and that 88 breakpoints should be removed while we step. 89 90 This variable is set either: 91 - in proceed, when we resume inferior on user's explicit request 92 - in keep_going, if handle_inferior_event decides we need to 93 step over breakpoint. 94 95 The variable is cleared in normal_stop. The proceed calls 96 wait_for_inferior, which calls handle_inferior_event in a loop, 97 and until wait_for_inferior exits, this variable is changed only 98 by keep_going. */ 99 int trap_expected; 100 101 /* Nonzero if the thread is being proceeded for a "finish" command 102 or a similar situation when stop_registers should be saved. */ 103 int proceed_to_finish; 104 105 /* Nonzero if the thread is being proceeded for an inferior function 106 call. */ 107 int in_infcall; 108 109 enum step_over_calls_kind step_over_calls; 110 111 /* Nonzero if stopped due to a step command. */ 112 int stop_step; 113 114 /* Chain containing status of breakpoint(s) the thread stopped 115 at. */ 116 bpstat stop_bpstat; 117 }; 118 119 /* Inferior thread specific part of `struct infcall_suspend_state'. 120 121 Inferior process counterpart is `struct inferior_suspend_state'. */ 122 123 struct thread_suspend_state 124 { 125 /* Last signal that the inferior received (why it stopped). */ 126 enum gdb_signal stop_signal; 127 }; 128 129 struct thread_info 130 { 131 struct thread_info *next; 132 ptid_t ptid; /* "Actual process id"; 133 In fact, this may be overloaded with 134 kernel thread id, etc. */ 135 int num; /* Convenient handle (GDB thread id) */ 136 137 /* The name of the thread, as specified by the user. This is NULL 138 if the thread does not have a user-given name. */ 139 char *name; 140 141 /* Non-zero means the thread is executing. Note: this is different 142 from saying that there is an active target and we are stopped at 143 a breakpoint, for instance. This is a real indicator whether the 144 thread is off and running. */ 145 int executing; 146 147 /* Frontend view of the thread state. Note that the RUNNING/STOPPED 148 states are different from EXECUTING. When the thread is stopped 149 internally while handling an internal event, like a software 150 single-step breakpoint, EXECUTING will be false, but running will 151 still be true. As a possible future extension, this could turn 152 into enum { stopped, exited, stepping, finishing, until(ling), 153 running ... } */ 154 int state; 155 156 /* If this is > 0, then it means there's code out there that relies 157 on this thread being listed. Don't delete it from the lists even 158 if we detect it exiting. */ 159 int refcount; 160 161 /* State of GDB control of inferior thread execution. 162 See `struct thread_control_state'. */ 163 struct thread_control_state control; 164 165 /* State of inferior thread to restore after GDB is done with an inferior 166 call. See `struct thread_suspend_state'. */ 167 struct thread_suspend_state suspend; 168 169 int current_line; 170 struct symtab *current_symtab; 171 172 /* Internal stepping state. */ 173 174 /* Record the pc of the thread the last time it stopped. This is 175 maintained by proceed and keep_going, and used in 176 adjust_pc_after_break to distinguish a hardware single-step 177 SIGTRAP from a breakpoint SIGTRAP. */ 178 CORE_ADDR prev_pc; 179 180 /* Should we step over breakpoint next time keep_going is called? */ 181 int stepping_over_breakpoint; 182 183 /* Set to TRUE if we should finish single-stepping over a breakpoint 184 after hitting the current step-resume breakpoint. The context here 185 is that GDB is to do `next' or `step' while signal arrives. 186 When stepping over a breakpoint and signal arrives, GDB will attempt 187 to skip signal handler, so it inserts a step_resume_breakpoint at the 188 signal return address, and resume inferior. 189 step_after_step_resume_breakpoint is set to TRUE at this moment in 190 order to keep GDB in mind that there is still a breakpoint to step over 191 when GDB gets back SIGTRAP from step_resume_breakpoint. */ 192 int step_after_step_resume_breakpoint; 193 194 /* Per-thread command support. */ 195 196 /* Pointer to what is left to do for an execution command after the 197 target stops. Used only in asynchronous mode, by targets that 198 support async execution. Several execution commands use it. */ 199 struct continuation *continuations; 200 201 /* Similar to the above, but used when a single execution command 202 requires several resume/stop iterations. Used by the step 203 command. */ 204 struct continuation *intermediate_continuations; 205 206 /* If stepping, nonzero means step count is > 1 so don't print frame 207 next time inferior stops if it stops due to stepping. */ 208 int step_multi; 209 210 /* This is used to remember when a fork or vfork event was caught by 211 a catchpoint, and thus the event is to be followed at the next 212 resume of the thread, and not immediately. */ 213 struct target_waitstatus pending_follow; 214 215 /* True if this thread has been explicitly requested to stop. */ 216 int stop_requested; 217 218 /* The initiating frame of a nexting operation, used for deciding 219 which exceptions to intercept. If it is null_frame_id no 220 bp_longjmp or bp_exception but longjmp has been caught just for 221 bp_longjmp_call_dummy. */ 222 struct frame_id initiating_frame; 223 224 /* Private data used by the target vector implementation. */ 225 struct private_thread_info *private; 226 227 /* Function that is called to free PRIVATE. If this is NULL, then 228 xfree will be called on PRIVATE. */ 229 void (*private_dtor) (struct private_thread_info *); 230 231 /* Branch trace information for this thread. */ 232 struct btrace_thread_info btrace; 233 }; 234 235 /* Create an empty thread list, or empty the existing one. */ 236 extern void init_thread_list (void); 237 238 /* Add a thread to the thread list, print a message 239 that a new thread is found, and return the pointer to 240 the new thread. Caller my use this pointer to 241 initialize the private thread data. */ 242 extern struct thread_info *add_thread (ptid_t ptid); 243 244 /* Same as add_thread, but does not print a message 245 about new thread. */ 246 extern struct thread_info *add_thread_silent (ptid_t ptid); 247 248 /* Same as add_thread, and sets the private info. */ 249 extern struct thread_info *add_thread_with_info (ptid_t ptid, 250 struct private_thread_info *); 251 252 /* Delete an existing thread list entry. */ 253 extern void delete_thread (ptid_t); 254 255 /* Delete an existing thread list entry, and be quiet about it. Used 256 after the process this thread having belonged to having already 257 exited, for example. */ 258 extern void delete_thread_silent (ptid_t); 259 260 /* Delete a step_resume_breakpoint from the thread database. */ 261 extern void delete_step_resume_breakpoint (struct thread_info *); 262 263 /* Delete an exception_resume_breakpoint from the thread database. */ 264 extern void delete_exception_resume_breakpoint (struct thread_info *); 265 266 /* Translate the integer thread id (GDB's homegrown id, not the system's) 267 into a "pid" (which may be overloaded with extra thread information). */ 268 extern ptid_t thread_id_to_pid (int); 269 270 /* Translate a 'pid' (which may be overloaded with extra thread information) 271 into the integer thread id (GDB's homegrown id, not the system's). */ 272 extern int pid_to_thread_id (ptid_t ptid); 273 274 /* Boolean test for an already-known pid (which may be overloaded with 275 extra thread information). */ 276 extern int in_thread_list (ptid_t ptid); 277 278 /* Boolean test for an already-known thread id (GDB's homegrown id, 279 not the system's). */ 280 extern int valid_thread_id (int thread); 281 282 /* Search function to lookup a thread by 'pid'. */ 283 extern struct thread_info *find_thread_ptid (ptid_t ptid); 284 285 /* Find thread by GDB user-visible thread number. */ 286 struct thread_info *find_thread_id (int num); 287 288 /* Finds the first thread of the inferior given by PID. If PID is -1, 289 returns the first thread in the list. */ 290 struct thread_info *first_thread_of_process (int pid); 291 292 /* Returns any thread of process PID. */ 293 extern struct thread_info *any_thread_of_process (int pid); 294 295 /* Returns any non-exited thread of process PID, giving preference for 296 not executing threads. */ 297 extern struct thread_info *any_live_thread_of_process (int pid); 298 299 /* Change the ptid of thread OLD_PTID to NEW_PTID. */ 300 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid); 301 302 /* Iterator function to call a user-provided callback function 303 once for each known thread. */ 304 typedef int (*thread_callback_func) (struct thread_info *, void *); 305 extern struct thread_info *iterate_over_threads (thread_callback_func, void *); 306 307 /* Traverse all threads. */ 308 309 #define ALL_THREADS(T) \ 310 for (T = thread_list; T; T = T->next) 311 312 extern int thread_count (void); 313 314 /* Switch from one thread to another. */ 315 extern void switch_to_thread (ptid_t ptid); 316 317 /* Marks thread PTID is running, or stopped. 318 If PIDGET (PTID) is -1, marks all threads. */ 319 extern void set_running (ptid_t ptid, int running); 320 321 /* Marks or clears thread(s) PTID as having been requested to stop. 322 If PTID is MINUS_ONE_PTID, applies to all threads. If 323 ptid_is_pid(PTID) is true, applies to all threads of the process 324 pointed at by PTID. If STOP, then the THREAD_STOP_REQUESTED 325 observer is called with PTID as argument. */ 326 extern void set_stop_requested (ptid_t ptid, int stop); 327 328 /* NOTE: Since the thread state is not a boolean, most times, you do 329 not want to check it with negation. If you really want to check if 330 the thread is stopped, 331 332 use (good): 333 334 if (is_stopped (ptid)) 335 336 instead of (bad): 337 338 if (!is_running (ptid)) 339 340 The latter also returns true on exited threads, most likelly not 341 what you want. */ 342 343 /* Reports if in the frontend's perpective, thread PTID is running. */ 344 extern int is_running (ptid_t ptid); 345 346 /* Is this thread listed, but known to have exited? We keep it listed 347 (but not visible) until it's safe to delete. */ 348 extern int is_exited (ptid_t ptid); 349 350 /* In the frontend's perpective, is this thread stopped? */ 351 extern int is_stopped (ptid_t ptid); 352 353 /* In the frontend's perpective is there any thread running? */ 354 extern int any_running (void); 355 356 /* Marks thread PTID as executing, or not. If PIDGET (PTID) is -1, 357 marks all threads. 358 359 Note that this is different from the running state. See the 360 description of state and executing fields of struct 361 thread_info. */ 362 extern void set_executing (ptid_t ptid, int executing); 363 364 /* Reports if thread PTID is executing. */ 365 extern int is_executing (ptid_t ptid); 366 367 /* Merge the executing property of thread PTID over to its thread 368 state property (frontend running/stopped view). 369 370 "not executing" -> "stopped" 371 "executing" -> "running" 372 "exited" -> "exited" 373 374 If PIDGET (PTID) is -1, go over all threads. 375 376 Notifications are only emitted if the thread state did change. */ 377 extern void finish_thread_state (ptid_t ptid); 378 379 /* Same as FINISH_THREAD_STATE, but with an interface suitable to be 380 registered as a cleanup. PTID_P points to the ptid_t that is 381 passed to FINISH_THREAD_STATE. */ 382 extern void finish_thread_state_cleanup (void *ptid_p); 383 384 /* Commands with a prefix of `thread'. */ 385 extern struct cmd_list_element *thread_cmd_list; 386 387 /* Print notices on thread events (attach, detach, etc.), set with 388 `set print thread-events'. */ 389 extern int print_thread_events; 390 391 extern void print_thread_info (struct ui_out *uiout, char *threads, 392 int pid); 393 394 extern struct cleanup *make_cleanup_restore_current_thread (void); 395 396 /* Returns a pointer into the thread_info corresponding to 397 INFERIOR_PTID. INFERIOR_PTID *must* be in the thread list. */ 398 extern struct thread_info* inferior_thread (void); 399 400 extern void update_thread_list (void); 401 402 extern struct thread_info *thread_list; 403 404 #endif /* GDBTHREAD_H */ 405