1 /* Multi-process/thread control defs for GDB, the GNU debugger. 2 Copyright (C) 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1997, 1998, 1999, 3 2000, 2007, 2008, 2009, 2010, 2011 Free Software 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 /* Inferior thread specific part of `struct infcall_control_state'. 33 34 Inferior process counterpart is `struct inferior_control_state'. */ 35 36 struct thread_control_state 37 { 38 /* User/external stepping state. */ 39 40 /* Step-resume or longjmp-resume breakpoint. */ 41 struct breakpoint *step_resume_breakpoint; 42 43 /* Exception-resume breakpoint. */ 44 struct breakpoint *exception_resume_breakpoint; 45 46 /* Range to single step within. 47 48 If this is nonzero, respond to a single-step signal by continuing 49 to step if the pc is in this range. 50 51 If step_range_start and step_range_end are both 1, it means to 52 step for a single instruction (FIXME: it might clean up 53 wait_for_inferior in a minor way if this were changed to the 54 address of the instruction and that address plus one. But maybe 55 not). */ 56 CORE_ADDR step_range_start; /* Inclusive */ 57 CORE_ADDR step_range_end; /* Exclusive */ 58 59 /* Stack frame address as of when stepping command was issued. 60 This is how we know when we step into a subroutine call, and how 61 to set the frame for the breakpoint used to step out. */ 62 struct frame_id step_frame_id; 63 64 /* Similarly, the frame ID of the underlying stack frame (skipping 65 any inlined frames). */ 66 struct frame_id step_stack_frame_id; 67 68 /* Nonzero if we are presently stepping over a breakpoint. 69 70 If we hit a breakpoint or watchpoint, and then continue, we need 71 to single step the current thread with breakpoints disabled, to 72 avoid hitting the same breakpoint or watchpoint again. And we 73 should step just a single thread and keep other threads stopped, 74 so that other threads don't miss breakpoints while they are 75 removed. 76 77 So, this variable simultaneously means that we need to single 78 step the current thread, keep other threads stopped, and that 79 breakpoints should be removed while we step. 80 81 This variable is set either: 82 - in proceed, when we resume inferior on user's explicit request 83 - in keep_going, if handle_inferior_event decides we need to 84 step over breakpoint. 85 86 The variable is cleared in normal_stop. The proceed calls 87 wait_for_inferior, which calls handle_inferior_event in a loop, 88 and until wait_for_inferior exits, this variable is changed only 89 by keep_going. */ 90 int trap_expected; 91 92 /* Nonzero if the thread is being proceeded for a "finish" command 93 or a similar situation when stop_registers should be saved. */ 94 int proceed_to_finish; 95 96 /* Nonzero if the thread is being proceeded for an inferior function 97 call. */ 98 int in_infcall; 99 100 enum step_over_calls_kind step_over_calls; 101 102 /* Nonzero if stopped due to a step command. */ 103 int stop_step; 104 105 /* Chain containing status of breakpoint(s) the thread stopped 106 at. */ 107 bpstat stop_bpstat; 108 }; 109 110 /* Inferior thread specific part of `struct infcall_suspend_state'. 111 112 Inferior process counterpart is `struct inferior_suspend_state'. */ 113 114 struct thread_suspend_state 115 { 116 /* Last signal that the inferior received (why it stopped). */ 117 enum target_signal stop_signal; 118 }; 119 120 struct thread_info 121 { 122 struct thread_info *next; 123 ptid_t ptid; /* "Actual process id"; 124 In fact, this may be overloaded with 125 kernel thread id, etc. */ 126 int num; /* Convenient handle (GDB thread id) */ 127 128 /* The name of the thread, as specified by the user. This is NULL 129 if the thread does not have a user-given name. */ 130 char *name; 131 132 /* Non-zero means the thread is executing. Note: this is different 133 from saying that there is an active target and we are stopped at 134 a breakpoint, for instance. This is a real indicator whether the 135 thread is off and running. */ 136 /* This field is internal to thread.c. Never access it directly, 137 use is_executing instead. */ 138 int executing_; 139 140 /* Frontend view of the thread state. Note that the RUNNING/STOPPED 141 states are different from EXECUTING. When the thread is stopped 142 internally while handling an internal event, like a software 143 single-step breakpoint, EXECUTING will be false, but running will 144 still be true. As a possible future extension, this could turn 145 into enum { stopped, exited, stepping, finishing, until(ling), 146 running ... } */ 147 /* This field is internal to thread.c. Never access it directly, 148 use is_running instead. */ 149 int state_; 150 151 /* If this is > 0, then it means there's code out there that relies 152 on this thread being listed. Don't delete it from the lists even 153 if we detect it exiting. */ 154 int refcount; 155 156 /* State of GDB control of inferior thread execution. 157 See `struct thread_control_state'. */ 158 struct thread_control_state control; 159 160 /* State of inferior thread to restore after GDB is done with an inferior 161 call. See `struct thread_suspend_state'. */ 162 struct thread_suspend_state suspend; 163 164 int current_line; 165 struct symtab *current_symtab; 166 167 /* Internal stepping state. */ 168 169 /* Record the pc of the thread the last time it stopped. This is 170 maintained by proceed and keep_going, and used in 171 adjust_pc_after_break to distinguish a hardware single-step 172 SIGTRAP from a breakpoint SIGTRAP. */ 173 CORE_ADDR prev_pc; 174 175 /* Should we step over breakpoint next time keep_going is called? */ 176 int stepping_over_breakpoint; 177 178 /* Set to TRUE if we should finish single-stepping over a breakpoint 179 after hitting the current step-resume breakpoint. */ 180 int step_after_step_resume_breakpoint; 181 182 /* This is set TRUE when a catchpoint of a shared library event 183 triggers. Since we don't wish to leave the inferior in the 184 solib hook when we report the event, we step the inferior 185 back to user code before stopping and reporting the event. */ 186 int stepping_through_solib_after_catch; 187 188 /* When stepping_through_solib_after_catch is TRUE, this is a 189 list of the catchpoints that should be reported as triggering 190 when we finally do stop stepping. */ 191 bpstat stepping_through_solib_catchpoints; 192 193 /* Per-thread command support. */ 194 195 /* Pointer to what is left to do for an execution command after the 196 target stops. Used only in asynchronous mode, by targets that 197 support async execution. Several execution commands use it. */ 198 struct continuation *continuations; 199 200 /* Similar to the above, but used when a single execution command 201 requires several resume/stop iterations. Used by the step 202 command. */ 203 struct continuation *intermediate_continuations; 204 205 /* If stepping, nonzero means step count is > 1 so don't print frame 206 next time inferior stops if it stops due to stepping. */ 207 int step_multi; 208 209 /* This is used to remember when a fork or vfork event was caught by 210 a catchpoint, and thus the event is to be followed at the next 211 resume of the thread, and not immediately. */ 212 struct target_waitstatus pending_follow; 213 214 /* True if this thread has been explicitly requested to stop. */ 215 int stop_requested; 216 217 /* The initiating frame of a nexting operation, used for deciding 218 which exceptions to intercept. */ 219 struct frame_id initiating_frame; 220 221 /* Private data used by the target vector implementation. */ 222 struct private_thread_info *private; 223 224 /* Function that is called to free PRIVATE. If this is NULL, then 225 xfree will be called on PRIVATE. */ 226 void (*private_dtor) (struct private_thread_info *); 227 }; 228 229 /* Create an empty thread list, or empty the existing one. */ 230 extern void init_thread_list (void); 231 232 /* Add a thread to the thread list, print a message 233 that a new thread is found, and return the pointer to 234 the new thread. Caller my use this pointer to 235 initialize the private thread data. */ 236 extern struct thread_info *add_thread (ptid_t ptid); 237 238 /* Same as add_thread, but does not print a message 239 about new thread. */ 240 extern struct thread_info *add_thread_silent (ptid_t ptid); 241 242 /* Same as add_thread, and sets the private info. */ 243 extern struct thread_info *add_thread_with_info (ptid_t ptid, 244 struct private_thread_info *); 245 246 /* Delete an existing thread list entry. */ 247 extern void delete_thread (ptid_t); 248 249 /* Delete an existing thread list entry, and be quiet about it. Used 250 after the process this thread having belonged to having already 251 exited, for example. */ 252 extern void delete_thread_silent (ptid_t); 253 254 /* Delete a step_resume_breakpoint from the thread database. */ 255 extern void delete_step_resume_breakpoint (struct thread_info *); 256 257 /* Delete an exception_resume_breakpoint from the thread database. */ 258 extern void delete_exception_resume_breakpoint (struct thread_info *); 259 260 /* Translate the integer thread id (GDB's homegrown id, not the system's) 261 into a "pid" (which may be overloaded with extra thread information). */ 262 extern ptid_t thread_id_to_pid (int); 263 264 /* Translate a 'pid' (which may be overloaded with extra thread information) 265 into the integer thread id (GDB's homegrown id, not the system's). */ 266 extern int pid_to_thread_id (ptid_t ptid); 267 268 /* Boolean test for an already-known pid (which may be overloaded with 269 extra thread information). */ 270 extern int in_thread_list (ptid_t ptid); 271 272 /* Boolean test for an already-known thread id (GDB's homegrown id, 273 not the system's). */ 274 extern int valid_thread_id (int thread); 275 276 /* Search function to lookup a thread by 'pid'. */ 277 extern struct thread_info *find_thread_ptid (ptid_t ptid); 278 279 /* Find thread by GDB user-visible thread number. */ 280 struct thread_info *find_thread_id (int num); 281 282 /* Finds the first thread of the inferior given by PID. If PID is -1, 283 returns the first thread in the list. */ 284 struct thread_info *first_thread_of_process (int pid); 285 286 /* Returns any thread of process PID. */ 287 extern struct thread_info *any_thread_of_process (int pid); 288 289 /* Returns any non-exited thread of process PID, giving preference for 290 not executing threads. */ 291 extern struct thread_info *any_live_thread_of_process (int pid); 292 293 /* Change the ptid of thread OLD_PTID to NEW_PTID. */ 294 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid); 295 296 /* Iterator function to call a user-provided callback function 297 once for each known thread. */ 298 typedef int (*thread_callback_func) (struct thread_info *, void *); 299 extern struct thread_info *iterate_over_threads (thread_callback_func, void *); 300 301 extern int thread_count (void); 302 303 /* Switch from one thread to another. */ 304 extern void switch_to_thread (ptid_t ptid); 305 306 /* Marks thread PTID is running, or stopped. 307 If PIDGET (PTID) is -1, marks all threads. */ 308 extern void set_running (ptid_t ptid, int running); 309 310 /* Marks or clears thread(s) PTID as having been requested to stop. 311 If PTID is MINUS_ONE_PTID, applies to all threads. If 312 ptid_is_pid(PTID) is true, applies to all threads of the process 313 pointed at by PTID. If STOP, then the THREAD_STOP_REQUESTED 314 observer is called with PTID as argument. */ 315 extern void set_stop_requested (ptid_t ptid, int stop); 316 317 /* NOTE: Since the thread state is not a boolean, most times, you do 318 not want to check it with negation. If you really want to check if 319 the thread is stopped, 320 321 use (good): 322 323 if (is_stopped (ptid)) 324 325 instead of (bad): 326 327 if (!is_running (ptid)) 328 329 The latter also returns true on exited threads, most likelly not 330 what you want. */ 331 332 /* Reports if in the frontend's perpective, thread PTID is running. */ 333 extern int is_running (ptid_t ptid); 334 335 /* Is this thread listed, but known to have exited? We keep it listed 336 (but not visible) until it's safe to delete. */ 337 extern int is_exited (ptid_t ptid); 338 339 /* In the frontend's perpective, is this thread stopped? */ 340 extern int is_stopped (ptid_t ptid); 341 342 /* In the frontend's perpective is there any thread running? */ 343 extern int any_running (void); 344 345 /* Marks thread PTID as executing, or not. If PIDGET (PTID) is -1, 346 marks all threads. 347 348 Note that this is different from the running state. See the 349 description of state_ and executing_ fields of struct 350 thread_info. */ 351 extern void set_executing (ptid_t ptid, int executing); 352 353 /* Reports if thread PTID is executing. */ 354 extern int is_executing (ptid_t ptid); 355 356 /* Merge the executing property of thread PTID over to its thread 357 state property (frontend running/stopped view). 358 359 "not executing" -> "stopped" 360 "executing" -> "running" 361 "exited" -> "exited" 362 363 If PIDGET (PTID) is -1, go over all threads. 364 365 Notifications are only emitted if the thread state did change. */ 366 extern void finish_thread_state (ptid_t ptid); 367 368 /* Same as FINISH_THREAD_STATE, but with an interface suitable to be 369 registered as a cleanup. PTID_P points to the ptid_t that is 370 passed to FINISH_THREAD_STATE. */ 371 extern void finish_thread_state_cleanup (void *ptid_p); 372 373 /* Commands with a prefix of `thread'. */ 374 extern struct cmd_list_element *thread_cmd_list; 375 376 /* Print notices on thread events (attach, detach, etc.), set with 377 `set print thread-events'. */ 378 extern int print_thread_events; 379 380 extern void print_thread_info (struct ui_out *uiout, char *threads, 381 int pid); 382 383 extern struct cleanup *make_cleanup_restore_current_thread (void); 384 385 /* Returns a pointer into the thread_info corresponding to 386 INFERIOR_PTID. INFERIOR_PTID *must* be in the thread list. */ 387 extern struct thread_info* inferior_thread (void); 388 389 extern void update_thread_list (void); 390 391 #endif /* GDBTHREAD_H */ 392