| 1 | /* Continuations for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 1986-2014 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "gdbthread.h" |
| 22 | #include "inferior.h" |
| 23 | #include "continuations.h" |
| 24 | |
| 25 | struct continuation |
| 26 | { |
| 27 | struct continuation *next; |
| 28 | continuation_ftype *function; |
| 29 | continuation_free_arg_ftype *free_arg; |
| 30 | void *arg; |
| 31 | }; |
| 32 | |
| 33 | /* Add a new continuation to the continuation chain. Args are |
| 34 | FUNCTION to run the continuation up with, and ARG to pass to |
| 35 | it. */ |
| 36 | |
| 37 | static void |
| 38 | make_continuation (struct continuation **pmy_chain, |
| 39 | continuation_ftype *function, |
| 40 | void *arg, void (*free_arg) (void *)) |
| 41 | { |
| 42 | struct continuation *new = XNEW (struct continuation); |
| 43 | |
| 44 | new->next = *pmy_chain; |
| 45 | new->function = function; |
| 46 | new->free_arg = free_arg; |
| 47 | new->arg = arg; |
| 48 | *pmy_chain = new; |
| 49 | } |
| 50 | |
| 51 | static void |
| 52 | do_my_continuations_1 (struct continuation **pmy_chain, int err) |
| 53 | { |
| 54 | struct continuation *ptr; |
| 55 | |
| 56 | while ((ptr = *pmy_chain) != NULL) |
| 57 | { |
| 58 | *pmy_chain = ptr->next; /* Do this first in case of recursion. */ |
| 59 | (*ptr->function) (ptr->arg, err); |
| 60 | if (ptr->free_arg) |
| 61 | (*ptr->free_arg) (ptr->arg); |
| 62 | xfree (ptr); |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | static void |
| 67 | do_my_continuations (struct continuation **list, int err) |
| 68 | { |
| 69 | struct continuation *continuations; |
| 70 | |
| 71 | if (*list == NULL) |
| 72 | return; |
| 73 | |
| 74 | /* Copy the list header into another pointer, and set the global |
| 75 | list header to null, so that the global list can change as a side |
| 76 | effect of invoking the continuations and the processing of the |
| 77 | preexisting continuations will not be affected. */ |
| 78 | |
| 79 | continuations = *list; |
| 80 | *list = NULL; |
| 81 | |
| 82 | /* Work now on the list we have set aside. */ |
| 83 | do_my_continuations_1 (&continuations, err); |
| 84 | } |
| 85 | |
| 86 | static void |
| 87 | discard_my_continuations_1 (struct continuation **pmy_chain) |
| 88 | { |
| 89 | struct continuation *ptr; |
| 90 | |
| 91 | while ((ptr = *pmy_chain) != NULL) |
| 92 | { |
| 93 | *pmy_chain = ptr->next; |
| 94 | if (ptr->free_arg) |
| 95 | (*ptr->free_arg) (ptr->arg); |
| 96 | xfree (ptr); |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | static void |
| 101 | discard_my_continuations (struct continuation **list) |
| 102 | { |
| 103 | discard_my_continuations_1 (list); |
| 104 | *list = NULL; |
| 105 | } |
| 106 | |
| 107 | /* Add a continuation to the continuation list of INFERIOR. The new |
| 108 | continuation will be added at the front. */ |
| 109 | |
| 110 | void |
| 111 | add_inferior_continuation (continuation_ftype *hook, void *args, |
| 112 | continuation_free_arg_ftype *free_arg) |
| 113 | { |
| 114 | struct inferior *inf = current_inferior (); |
| 115 | |
| 116 | make_continuation (&inf->continuations, hook, args, free_arg); |
| 117 | } |
| 118 | |
| 119 | /* Do all continuations of the current inferior. */ |
| 120 | |
| 121 | void |
| 122 | do_all_inferior_continuations (int err) |
| 123 | { |
| 124 | struct inferior *inf = current_inferior (); |
| 125 | do_my_continuations (&inf->continuations, err); |
| 126 | } |
| 127 | |
| 128 | /* Get rid of all the inferior-wide continuations of INF. */ |
| 129 | |
| 130 | void |
| 131 | discard_all_inferior_continuations (struct inferior *inf) |
| 132 | { |
| 133 | discard_my_continuations (&inf->continuations); |
| 134 | } |
| 135 | |
| 136 | /* Add a continuation to the continuation list of THREAD. The new |
| 137 | continuation will be added at the front. */ |
| 138 | |
| 139 | void |
| 140 | add_continuation (struct thread_info *thread, |
| 141 | continuation_ftype *hook, void *args, |
| 142 | continuation_free_arg_ftype *free_arg) |
| 143 | { |
| 144 | make_continuation (&thread->continuations, hook, args, free_arg); |
| 145 | } |
| 146 | |
| 147 | static void |
| 148 | restore_thread_cleanup (void *arg) |
| 149 | { |
| 150 | ptid_t *ptid_p = arg; |
| 151 | |
| 152 | switch_to_thread (*ptid_p); |
| 153 | } |
| 154 | |
| 155 | /* Walk down the continuation list of PTID, and execute all the |
| 156 | continuations. There is a problem though. In some cases new |
| 157 | continuations may be added while we are in the middle of this loop. |
| 158 | If this happens they will be added in the front, and done before we |
| 159 | have a chance of exhausting those that were already there. We need |
| 160 | to then save the beginning of the list in a pointer and do the |
| 161 | continuations from there on, instead of using the global beginning |
| 162 | of list as our iteration pointer. */ |
| 163 | |
| 164 | static void |
| 165 | do_all_continuations_ptid (ptid_t ptid, |
| 166 | struct continuation **continuations_p, |
| 167 | int err) |
| 168 | { |
| 169 | struct cleanup *old_chain; |
| 170 | ptid_t current_thread; |
| 171 | |
| 172 | if (*continuations_p == NULL) |
| 173 | return; |
| 174 | |
| 175 | current_thread = inferior_ptid; |
| 176 | |
| 177 | /* Restore selected thread on exit. Don't try to restore the frame |
| 178 | as well, because: |
| 179 | |
| 180 | - When running continuations, the selected frame is always #0. |
| 181 | |
| 182 | - The continuations may trigger symbol file loads, which may |
| 183 | change the frame layout (frame ids change), which would trigger |
| 184 | a warning if we used make_cleanup_restore_current_thread. */ |
| 185 | |
| 186 | old_chain = make_cleanup (restore_thread_cleanup, ¤t_thread); |
| 187 | |
| 188 | /* Let the continuation see this thread as selected. */ |
| 189 | switch_to_thread (ptid); |
| 190 | |
| 191 | do_my_continuations (continuations_p, err); |
| 192 | |
| 193 | do_cleanups (old_chain); |
| 194 | } |
| 195 | |
| 196 | /* Callback for iterate over threads. */ |
| 197 | |
| 198 | static int |
| 199 | do_all_continuations_thread_callback (struct thread_info *thread, void *data) |
| 200 | { |
| 201 | int err = * (int *) data; |
| 202 | do_all_continuations_ptid (thread->ptid, &thread->continuations, err); |
| 203 | return 0; |
| 204 | } |
| 205 | |
| 206 | /* Do all continuations of thread THREAD. */ |
| 207 | |
| 208 | void |
| 209 | do_all_continuations_thread (struct thread_info *thread, int err) |
| 210 | { |
| 211 | do_all_continuations_thread_callback (thread, &err); |
| 212 | } |
| 213 | |
| 214 | /* Do all continuations of all threads. */ |
| 215 | |
| 216 | void |
| 217 | do_all_continuations (int err) |
| 218 | { |
| 219 | iterate_over_threads (do_all_continuations_thread_callback, &err); |
| 220 | } |
| 221 | |
| 222 | /* Callback for iterate over threads. */ |
| 223 | |
| 224 | static int |
| 225 | discard_all_continuations_thread_callback (struct thread_info *thread, |
| 226 | void *data) |
| 227 | { |
| 228 | discard_my_continuations (&thread->continuations); |
| 229 | return 0; |
| 230 | } |
| 231 | |
| 232 | /* Get rid of all the continuations of THREAD. */ |
| 233 | |
| 234 | void |
| 235 | discard_all_continuations_thread (struct thread_info *thread) |
| 236 | { |
| 237 | discard_all_continuations_thread_callback (thread, NULL); |
| 238 | } |
| 239 | |
| 240 | /* Get rid of all the continuations of all threads. */ |
| 241 | |
| 242 | void |
| 243 | discard_all_continuations (void) |
| 244 | { |
| 245 | iterate_over_threads (discard_all_continuations_thread_callback, NULL); |
| 246 | } |
| 247 | |
| 248 | |
| 249 | /* Add a continuation to the intermediate continuation list of THREAD. |
| 250 | The new continuation will be added at the front. */ |
| 251 | |
| 252 | void |
| 253 | add_intermediate_continuation (struct thread_info *thread, |
| 254 | continuation_ftype *hook, |
| 255 | void *args, |
| 256 | continuation_free_arg_ftype *free_arg) |
| 257 | { |
| 258 | make_continuation (&thread->intermediate_continuations, hook, |
| 259 | args, free_arg); |
| 260 | } |
| 261 | |
| 262 | /* Walk down the cmd_continuation list, and execute all the |
| 263 | continuations. There is a problem though. In some cases new |
| 264 | continuations may be added while we are in the middle of this |
| 265 | loop. If this happens they will be added in the front, and done |
| 266 | before we have a chance of exhausting those that were already |
| 267 | there. We need to then save the beginning of the list in a pointer |
| 268 | and do the continuations from there on, instead of using the |
| 269 | global beginning of list as our iteration pointer. */ |
| 270 | |
| 271 | static int |
| 272 | do_all_intermediate_continuations_thread_callback (struct thread_info *thread, |
| 273 | void *data) |
| 274 | { |
| 275 | int err = * (int *) data; |
| 276 | |
| 277 | do_all_continuations_ptid (thread->ptid, |
| 278 | &thread->intermediate_continuations, err); |
| 279 | return 0; |
| 280 | } |
| 281 | |
| 282 | /* Do all intermediate continuations of thread THREAD. */ |
| 283 | |
| 284 | void |
| 285 | do_all_intermediate_continuations_thread (struct thread_info *thread, int err) |
| 286 | { |
| 287 | do_all_intermediate_continuations_thread_callback (thread, &err); |
| 288 | } |
| 289 | |
| 290 | /* Do all intermediate continuations of all threads. */ |
| 291 | |
| 292 | void |
| 293 | do_all_intermediate_continuations (int err) |
| 294 | { |
| 295 | iterate_over_threads (do_all_intermediate_continuations_thread_callback, |
| 296 | &err); |
| 297 | } |
| 298 | |
| 299 | /* Callback for iterate over threads. */ |
| 300 | |
| 301 | static int |
| 302 | discard_all_intermediate_continuations_thread_callback (struct thread_info *thread, |
| 303 | void *data) |
| 304 | { |
| 305 | discard_my_continuations (&thread->intermediate_continuations); |
| 306 | return 0; |
| 307 | } |
| 308 | |
| 309 | /* Get rid of all the intermediate continuations of THREAD. */ |
| 310 | |
| 311 | void |
| 312 | discard_all_intermediate_continuations_thread (struct thread_info *thread) |
| 313 | { |
| 314 | discard_all_intermediate_continuations_thread_callback (thread, NULL); |
| 315 | } |
| 316 | |
| 317 | /* Get rid of all the intermediate continuations of all threads. */ |
| 318 | |
| 319 | void |
| 320 | discard_all_intermediate_continuations (void) |
| 321 | { |
| 322 | iterate_over_threads (discard_all_intermediate_continuations_thread_callback, |
| 323 | NULL); |
| 324 | } |