1 /* Multi-process/thread control defs for GDB, the GNU debugger. 2 Copyright (C) 1987-1993, 1997-2000, 2007-2012 Free Software 3 Foundation, Inc. 4 Contributed by Lynx Real-Time Systems, Inc. Los Gatos, CA. 5 6 7 This file is part of GDB. 8 9 This program is free software; you can redistribute it and/or modify 10 it under the terms of the GNU General Public License as published by 11 the Free Software Foundation; either version 3 of the License, or 12 (at your option) any later version. 13 14 This program is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 21 22 #ifndef GDBTHREAD_H 23 #define GDBTHREAD_H 24 25 struct symtab; 26 27 #include "breakpoint.h" 28 #include "frame.h" 29 #include "ui-out.h" 30 #include "inferior.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 target_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. */ 220 struct frame_id initiating_frame; 221 222 /* Private data used by the target vector implementation. */ 223 struct private_thread_info *private; 224 225 /* Function that is called to free PRIVATE. If this is NULL, then 226 xfree will be called on PRIVATE. */ 227 void (*private_dtor) (struct private_thread_info *); 228 }; 229 230 /* Create an empty thread list, or empty the existing one. */ 231 extern void init_thread_list (void); 232 233 /* Add a thread to the thread list, print a message 234 that a new thread is found, and return the pointer to 235 the new thread. Caller my use this pointer to 236 initialize the private thread data. */ 237 extern struct thread_info *add_thread (ptid_t ptid); 238 239 /* Same as add_thread, but does not print a message 240 about new thread. */ 241 extern struct thread_info *add_thread_silent (ptid_t ptid); 242 243 /* Same as add_thread, and sets the private info. */ 244 extern struct thread_info *add_thread_with_info (ptid_t ptid, 245 struct private_thread_info *); 246 247 /* Delete an existing thread list entry. */ 248 extern void delete_thread (ptid_t); 249 250 /* Delete an existing thread list entry, and be quiet about it. Used 251 after the process this thread having belonged to having already 252 exited, for example. */ 253 extern void delete_thread_silent (ptid_t); 254 255 /* Delete a step_resume_breakpoint from the thread database. */ 256 extern void delete_step_resume_breakpoint (struct thread_info *); 257 258 /* Delete an exception_resume_breakpoint from the thread database. */ 259 extern void delete_exception_resume_breakpoint (struct thread_info *); 260 261 /* Translate the integer thread id (GDB's homegrown id, not the system's) 262 into a "pid" (which may be overloaded with extra thread information). */ 263 extern ptid_t thread_id_to_pid (int); 264 265 /* Translate a 'pid' (which may be overloaded with extra thread information) 266 into the integer thread id (GDB's homegrown id, not the system's). */ 267 extern int pid_to_thread_id (ptid_t ptid); 268 269 /* Boolean test for an already-known pid (which may be overloaded with 270 extra thread information). */ 271 extern int in_thread_list (ptid_t ptid); 272 273 /* Boolean test for an already-known thread id (GDB's homegrown id, 274 not the system's). */ 275 extern int valid_thread_id (int thread); 276 277 /* Search function to lookup a thread by 'pid'. */ 278 extern struct thread_info *find_thread_ptid (ptid_t ptid); 279 280 /* Find thread by GDB user-visible thread number. */ 281 struct thread_info *find_thread_id (int num); 282 283 /* Finds the first thread of the inferior given by PID. If PID is -1, 284 returns the first thread in the list. */ 285 struct thread_info *first_thread_of_process (int pid); 286 287 /* Returns any thread of process PID. */ 288 extern struct thread_info *any_thread_of_process (int pid); 289 290 /* Returns any non-exited thread of process PID, giving preference for 291 not executing threads. */ 292 extern struct thread_info *any_live_thread_of_process (int pid); 293 294 /* Change the ptid of thread OLD_PTID to NEW_PTID. */ 295 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid); 296 297 /* Iterator function to call a user-provided callback function 298 once for each known thread. */ 299 typedef int (*thread_callback_func) (struct thread_info *, void *); 300 extern struct thread_info *iterate_over_threads (thread_callback_func, void *); 301 302 extern int thread_count (void); 303 304 /* Switch from one thread to another. */ 305 extern void switch_to_thread (ptid_t ptid); 306 307 /* Marks thread PTID is running, or stopped. 308 If PIDGET (PTID) is -1, marks all threads. */ 309 extern void set_running (ptid_t ptid, int running); 310 311 /* Marks or clears thread(s) PTID as having been requested to stop. 312 If PTID is MINUS_ONE_PTID, applies to all threads. If 313 ptid_is_pid(PTID) is true, applies to all threads of the process 314 pointed at by PTID. If STOP, then the THREAD_STOP_REQUESTED 315 observer is called with PTID as argument. */ 316 extern void set_stop_requested (ptid_t ptid, int stop); 317 318 /* NOTE: Since the thread state is not a boolean, most times, you do 319 not want to check it with negation. If you really want to check if 320 the thread is stopped, 321 322 use (good): 323 324 if (is_stopped (ptid)) 325 326 instead of (bad): 327 328 if (!is_running (ptid)) 329 330 The latter also returns true on exited threads, most likelly not 331 what you want. */ 332 333 /* Reports if in the frontend's perpective, thread PTID is running. */ 334 extern int is_running (ptid_t ptid); 335 336 /* Is this thread listed, but known to have exited? We keep it listed 337 (but not visible) until it's safe to delete. */ 338 extern int is_exited (ptid_t ptid); 339 340 /* In the frontend's perpective, is this thread stopped? */ 341 extern int is_stopped (ptid_t ptid); 342 343 /* In the frontend's perpective is there any thread running? */ 344 extern int any_running (void); 345 346 /* Marks thread PTID as executing, or not. If PIDGET (PTID) is -1, 347 marks all threads. 348 349 Note that this is different from the running state. See the 350 description of state and executing fields of struct 351 thread_info. */ 352 extern void set_executing (ptid_t ptid, int executing); 353 354 /* Reports if thread PTID is executing. */ 355 extern int is_executing (ptid_t ptid); 356 357 /* Merge the executing property of thread PTID over to its thread 358 state property (frontend running/stopped view). 359 360 "not executing" -> "stopped" 361 "executing" -> "running" 362 "exited" -> "exited" 363 364 If PIDGET (PTID) is -1, go over all threads. 365 366 Notifications are only emitted if the thread state did change. */ 367 extern void finish_thread_state (ptid_t ptid); 368 369 /* Same as FINISH_THREAD_STATE, but with an interface suitable to be 370 registered as a cleanup. PTID_P points to the ptid_t that is 371 passed to FINISH_THREAD_STATE. */ 372 extern void finish_thread_state_cleanup (void *ptid_p); 373 374 /* Commands with a prefix of `thread'. */ 375 extern struct cmd_list_element *thread_cmd_list; 376 377 /* Print notices on thread events (attach, detach, etc.), set with 378 `set print thread-events'. */ 379 extern int print_thread_events; 380 381 extern void print_thread_info (struct ui_out *uiout, char *threads, 382 int pid); 383 384 extern struct cleanup *make_cleanup_restore_current_thread (void); 385 386 /* Returns a pointer into the thread_info corresponding to 387 INFERIOR_PTID. INFERIOR_PTID *must* be in the thread list. */ 388 extern struct thread_info* inferior_thread (void); 389 390 extern void update_thread_list (void); 391 392 #endif /* GDBTHREAD_H */ 393