| 1 | /* Event loop machinery for GDB, the GNU debugger. |
| 2 | Copyright (C) 1999-2019 Free Software Foundation, Inc. |
| 3 | Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions. |
| 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 "event-loop.h" |
| 22 | #include "event-top.h" |
| 23 | #include "common/queue.h" |
| 24 | #include "ser-event.h" |
| 25 | |
| 26 | #ifdef HAVE_POLL |
| 27 | #if defined (HAVE_POLL_H) |
| 28 | #include <poll.h> |
| 29 | #elif defined (HAVE_SYS_POLL_H) |
| 30 | #include <sys/poll.h> |
| 31 | #endif |
| 32 | #endif |
| 33 | |
| 34 | #include <sys/types.h> |
| 35 | #include "common/gdb_sys_time.h" |
| 36 | #include "gdb_select.h" |
| 37 | #include "observable.h" |
| 38 | #include "top.h" |
| 39 | |
| 40 | /* Tell create_file_handler what events we are interested in. |
| 41 | This is used by the select version of the event loop. */ |
| 42 | |
| 43 | #define GDB_READABLE (1<<1) |
| 44 | #define GDB_WRITABLE (1<<2) |
| 45 | #define GDB_EXCEPTION (1<<3) |
| 46 | |
| 47 | /* Data point to pass to the event handler. */ |
| 48 | typedef union event_data |
| 49 | { |
| 50 | void *ptr; |
| 51 | int integer; |
| 52 | } event_data; |
| 53 | |
| 54 | typedef struct gdb_event gdb_event; |
| 55 | typedef void (event_handler_func) (event_data); |
| 56 | |
| 57 | /* Event for the GDB event system. Events are queued by calling |
| 58 | async_queue_event and serviced later on by gdb_do_one_event. An |
| 59 | event can be, for instance, a file descriptor becoming ready to be |
| 60 | read. Servicing an event simply means that the procedure PROC will |
| 61 | be called. We have 2 queues, one for file handlers that we listen |
| 62 | to in the event loop, and one for the file handlers+events that are |
| 63 | ready. The procedure PROC associated with each event is dependant |
| 64 | of the event source. In the case of monitored file descriptors, it |
| 65 | is always the same (handle_file_event). Its duty is to invoke the |
| 66 | handler associated with the file descriptor whose state change |
| 67 | generated the event, plus doing other cleanups and such. In the |
| 68 | case of async signal handlers, it is |
| 69 | invoke_async_signal_handler. */ |
| 70 | |
| 71 | typedef struct gdb_event |
| 72 | { |
| 73 | /* Procedure to call to service this event. */ |
| 74 | event_handler_func *proc; |
| 75 | |
| 76 | /* Data to pass to the event handler. */ |
| 77 | event_data data; |
| 78 | } *gdb_event_p; |
| 79 | |
| 80 | /* Information about each file descriptor we register with the event |
| 81 | loop. */ |
| 82 | |
| 83 | typedef struct file_handler |
| 84 | { |
| 85 | int fd; /* File descriptor. */ |
| 86 | int mask; /* Events we want to monitor: POLLIN, etc. */ |
| 87 | int ready_mask; /* Events that have been seen since |
| 88 | the last time. */ |
| 89 | handler_func *proc; /* Procedure to call when fd is ready. */ |
| 90 | gdb_client_data client_data; /* Argument to pass to proc. */ |
| 91 | int error; /* Was an error detected on this fd? */ |
| 92 | struct file_handler *next_file; /* Next registered file descriptor. */ |
| 93 | } |
| 94 | file_handler; |
| 95 | |
| 96 | /* PROC is a function to be invoked when the READY flag is set. This |
| 97 | happens when there has been a signal and the corresponding signal |
| 98 | handler has 'triggered' this async_signal_handler for execution. |
| 99 | The actual work to be done in response to a signal will be carried |
| 100 | out by PROC at a later time, within process_event. This provides a |
| 101 | deferred execution of signal handlers. |
| 102 | |
| 103 | Async_init_signals takes care of setting up such an |
| 104 | async_signal_handler for each interesting signal. */ |
| 105 | |
| 106 | typedef struct async_signal_handler |
| 107 | { |
| 108 | int ready; /* If ready, call this handler |
| 109 | from the main event loop, using |
| 110 | invoke_async_handler. */ |
| 111 | struct async_signal_handler *next_handler; /* Ptr to next handler. */ |
| 112 | sig_handler_func *proc; /* Function to call to do the work. */ |
| 113 | gdb_client_data client_data; /* Argument to async_handler_func. */ |
| 114 | } |
| 115 | async_signal_handler; |
| 116 | |
| 117 | /* PROC is a function to be invoked when the READY flag is set. This |
| 118 | happens when the event has been marked with |
| 119 | MARK_ASYNC_EVENT_HANDLER. The actual work to be done in response |
| 120 | to an event will be carried out by PROC at a later time, within |
| 121 | process_event. This provides a deferred execution of event |
| 122 | handlers. */ |
| 123 | typedef struct async_event_handler |
| 124 | { |
| 125 | /* If ready, call this handler from the main event loop, using |
| 126 | invoke_event_handler. */ |
| 127 | int ready; |
| 128 | |
| 129 | /* Point to next handler. */ |
| 130 | struct async_event_handler *next_handler; |
| 131 | |
| 132 | /* Function to call to do the work. */ |
| 133 | async_event_handler_func *proc; |
| 134 | |
| 135 | /* Argument to PROC. */ |
| 136 | gdb_client_data client_data; |
| 137 | } |
| 138 | async_event_handler; |
| 139 | |
| 140 | /* Gdb_notifier is just a list of file descriptors gdb is interested in. |
| 141 | These are the input file descriptor, and the target file |
| 142 | descriptor. We have two flavors of the notifier, one for platforms |
| 143 | that have the POLL function, the other for those that don't, and |
| 144 | only support SELECT. Each of the elements in the gdb_notifier list is |
| 145 | basically a description of what kind of events gdb is interested |
| 146 | in, for each fd. */ |
| 147 | |
| 148 | /* As of 1999-04-30 only the input file descriptor is registered with the |
| 149 | event loop. */ |
| 150 | |
| 151 | /* Do we use poll or select ? */ |
| 152 | #ifdef HAVE_POLL |
| 153 | #define USE_POLL 1 |
| 154 | #else |
| 155 | #define USE_POLL 0 |
| 156 | #endif /* HAVE_POLL */ |
| 157 | |
| 158 | static unsigned char use_poll = USE_POLL; |
| 159 | |
| 160 | #ifdef USE_WIN32API |
| 161 | #include <windows.h> |
| 162 | #include <io.h> |
| 163 | #endif |
| 164 | |
| 165 | static struct |
| 166 | { |
| 167 | /* Ptr to head of file handler list. */ |
| 168 | file_handler *first_file_handler; |
| 169 | |
| 170 | /* Next file handler to handle, for the select variant. To level |
| 171 | the fairness across event sources, we serve file handlers in a |
| 172 | round-robin-like fashion. The number and order of the polled |
| 173 | file handlers may change between invocations, but this is good |
| 174 | enough. */ |
| 175 | file_handler *next_file_handler; |
| 176 | |
| 177 | #ifdef HAVE_POLL |
| 178 | /* Ptr to array of pollfd structures. */ |
| 179 | struct pollfd *poll_fds; |
| 180 | |
| 181 | /* Next file descriptor to handle, for the poll variant. To level |
| 182 | the fairness across event sources, we poll the file descriptors |
| 183 | in a round-robin-like fashion. The number and order of the |
| 184 | polled file descriptors may change between invocations, but |
| 185 | this is good enough. */ |
| 186 | int next_poll_fds_index; |
| 187 | |
| 188 | /* Timeout in milliseconds for calls to poll(). */ |
| 189 | int poll_timeout; |
| 190 | #endif |
| 191 | |
| 192 | /* Masks to be used in the next call to select. |
| 193 | Bits are set in response to calls to create_file_handler. */ |
| 194 | fd_set check_masks[3]; |
| 195 | |
| 196 | /* What file descriptors were found ready by select. */ |
| 197 | fd_set ready_masks[3]; |
| 198 | |
| 199 | /* Number of file descriptors to monitor (for poll). */ |
| 200 | /* Number of valid bits (highest fd value + 1) (for select). */ |
| 201 | int num_fds; |
| 202 | |
| 203 | /* Time structure for calls to select(). */ |
| 204 | struct timeval select_timeout; |
| 205 | |
| 206 | /* Flag to tell whether the timeout should be used. */ |
| 207 | int timeout_valid; |
| 208 | } |
| 209 | gdb_notifier; |
| 210 | |
| 211 | /* Structure associated with a timer. PROC will be executed at the |
| 212 | first occasion after WHEN. */ |
| 213 | struct gdb_timer |
| 214 | { |
| 215 | std::chrono::steady_clock::time_point when; |
| 216 | int timer_id; |
| 217 | struct gdb_timer *next; |
| 218 | timer_handler_func *proc; /* Function to call to do the work. */ |
| 219 | gdb_client_data client_data; /* Argument to async_handler_func. */ |
| 220 | }; |
| 221 | |
| 222 | /* List of currently active timers. It is sorted in order of |
| 223 | increasing timers. */ |
| 224 | static struct |
| 225 | { |
| 226 | /* Pointer to first in timer list. */ |
| 227 | struct gdb_timer *first_timer; |
| 228 | |
| 229 | /* Id of the last timer created. */ |
| 230 | int num_timers; |
| 231 | } |
| 232 | timer_list; |
| 233 | |
| 234 | /* All the async_signal_handlers gdb is interested in are kept onto |
| 235 | this list. */ |
| 236 | static struct |
| 237 | { |
| 238 | /* Pointer to first in handler list. */ |
| 239 | async_signal_handler *first_handler; |
| 240 | |
| 241 | /* Pointer to last in handler list. */ |
| 242 | async_signal_handler *last_handler; |
| 243 | } |
| 244 | sighandler_list; |
| 245 | |
| 246 | /* All the async_event_handlers gdb is interested in are kept onto |
| 247 | this list. */ |
| 248 | static struct |
| 249 | { |
| 250 | /* Pointer to first in handler list. */ |
| 251 | async_event_handler *first_handler; |
| 252 | |
| 253 | /* Pointer to last in handler list. */ |
| 254 | async_event_handler *last_handler; |
| 255 | } |
| 256 | async_event_handler_list; |
| 257 | |
| 258 | static int invoke_async_signal_handlers (void); |
| 259 | static void create_file_handler (int fd, int mask, handler_func *proc, |
| 260 | gdb_client_data client_data); |
| 261 | static int check_async_event_handlers (void); |
| 262 | static int gdb_wait_for_event (int); |
| 263 | static int update_wait_timeout (void); |
| 264 | static int poll_timers (void); |
| 265 | \f |
| 266 | |
| 267 | /* This event is signalled whenever an asynchronous handler needs to |
| 268 | defer an action to the event loop. */ |
| 269 | static struct serial_event *async_signal_handlers_serial_event; |
| 270 | |
| 271 | /* Callback registered with ASYNC_SIGNAL_HANDLERS_SERIAL_EVENT. */ |
| 272 | |
| 273 | static void |
| 274 | async_signals_handler (int error, gdb_client_data client_data) |
| 275 | { |
| 276 | /* Do nothing. Handlers are run by invoke_async_signal_handlers |
| 277 | from instead. */ |
| 278 | } |
| 279 | |
| 280 | void |
| 281 | initialize_async_signal_handlers (void) |
| 282 | { |
| 283 | async_signal_handlers_serial_event = make_serial_event (); |
| 284 | |
| 285 | add_file_handler (serial_event_fd (async_signal_handlers_serial_event), |
| 286 | async_signals_handler, NULL); |
| 287 | } |
| 288 | |
| 289 | /* Process one high level event. If nothing is ready at this time, |
| 290 | wait for something to happen (via gdb_wait_for_event), then process |
| 291 | it. Returns >0 if something was done otherwise returns <0 (this |
| 292 | can happen if there are no event sources to wait for). */ |
| 293 | |
| 294 | int |
| 295 | gdb_do_one_event (void) |
| 296 | { |
| 297 | static int event_source_head = 0; |
| 298 | const int number_of_sources = 3; |
| 299 | int current = 0; |
| 300 | |
| 301 | /* First let's see if there are any asynchronous signal handlers |
| 302 | that are ready. These would be the result of invoking any of the |
| 303 | signal handlers. */ |
| 304 | if (invoke_async_signal_handlers ()) |
| 305 | return 1; |
| 306 | |
| 307 | /* To level the fairness across event sources, we poll them in a |
| 308 | round-robin fashion. */ |
| 309 | for (current = 0; current < number_of_sources; current++) |
| 310 | { |
| 311 | int res; |
| 312 | |
| 313 | switch (event_source_head) |
| 314 | { |
| 315 | case 0: |
| 316 | /* Are any timers that are ready? */ |
| 317 | res = poll_timers (); |
| 318 | break; |
| 319 | case 1: |
| 320 | /* Are there events already waiting to be collected on the |
| 321 | monitored file descriptors? */ |
| 322 | res = gdb_wait_for_event (0); |
| 323 | break; |
| 324 | case 2: |
| 325 | /* Are there any asynchronous event handlers ready? */ |
| 326 | res = check_async_event_handlers (); |
| 327 | break; |
| 328 | default: |
| 329 | internal_error (__FILE__, __LINE__, |
| 330 | "unexpected event_source_head %d", |
| 331 | event_source_head); |
| 332 | } |
| 333 | |
| 334 | event_source_head++; |
| 335 | if (event_source_head == number_of_sources) |
| 336 | event_source_head = 0; |
| 337 | |
| 338 | if (res > 0) |
| 339 | return 1; |
| 340 | } |
| 341 | |
| 342 | /* Block waiting for a new event. If gdb_wait_for_event returns -1, |
| 343 | we should get out because this means that there are no event |
| 344 | sources left. This will make the event loop stop, and the |
| 345 | application exit. */ |
| 346 | |
| 347 | if (gdb_wait_for_event (1) < 0) |
| 348 | return -1; |
| 349 | |
| 350 | /* If gdb_wait_for_event has returned 1, it means that one event has |
| 351 | been handled. We break out of the loop. */ |
| 352 | return 1; |
| 353 | } |
| 354 | |
| 355 | /* Start up the event loop. This is the entry point to the event loop |
| 356 | from the command loop. */ |
| 357 | |
| 358 | void |
| 359 | start_event_loop (void) |
| 360 | { |
| 361 | /* Loop until there is nothing to do. This is the entry point to |
| 362 | the event loop engine. gdb_do_one_event will process one event |
| 363 | for each invocation. It blocks waiting for an event and then |
| 364 | processes it. */ |
| 365 | while (1) |
| 366 | { |
| 367 | int result = 0; |
| 368 | |
| 369 | TRY |
| 370 | { |
| 371 | result = gdb_do_one_event (); |
| 372 | } |
| 373 | CATCH (ex, RETURN_MASK_ALL) |
| 374 | { |
| 375 | exception_print (gdb_stderr, ex); |
| 376 | |
| 377 | /* If any exception escaped to here, we better enable |
| 378 | stdin. Otherwise, any command that calls async_disable_stdin, |
| 379 | and then throws, will leave stdin inoperable. */ |
| 380 | async_enable_stdin (); |
| 381 | /* If we long-jumped out of do_one_event, we probably didn't |
| 382 | get around to resetting the prompt, which leaves readline |
| 383 | in a messed-up state. Reset it here. */ |
| 384 | current_ui->prompt_state = PROMPT_NEEDED; |
| 385 | gdb::observers::command_error.notify (); |
| 386 | /* This call looks bizarre, but it is required. If the user |
| 387 | entered a command that caused an error, |
| 388 | after_char_processing_hook won't be called from |
| 389 | rl_callback_read_char_wrapper. Using a cleanup there |
| 390 | won't work, since we want this function to be called |
| 391 | after a new prompt is printed. */ |
| 392 | if (after_char_processing_hook) |
| 393 | (*after_char_processing_hook) (); |
| 394 | /* Maybe better to set a flag to be checked somewhere as to |
| 395 | whether display the prompt or not. */ |
| 396 | } |
| 397 | END_CATCH |
| 398 | |
| 399 | if (result < 0) |
| 400 | break; |
| 401 | } |
| 402 | |
| 403 | /* We are done with the event loop. There are no more event sources |
| 404 | to listen to. So we exit GDB. */ |
| 405 | return; |
| 406 | } |
| 407 | \f |
| 408 | |
| 409 | /* Wrapper function for create_file_handler, so that the caller |
| 410 | doesn't have to know implementation details about the use of poll |
| 411 | vs. select. */ |
| 412 | void |
| 413 | add_file_handler (int fd, handler_func * proc, gdb_client_data client_data) |
| 414 | { |
| 415 | #ifdef HAVE_POLL |
| 416 | struct pollfd fds; |
| 417 | #endif |
| 418 | |
| 419 | if (use_poll) |
| 420 | { |
| 421 | #ifdef HAVE_POLL |
| 422 | /* Check to see if poll () is usable. If not, we'll switch to |
| 423 | use select. This can happen on systems like |
| 424 | m68k-motorola-sys, `poll' cannot be used to wait for `stdin'. |
| 425 | On m68k-motorola-sysv, tty's are not stream-based and not |
| 426 | `poll'able. */ |
| 427 | fds.fd = fd; |
| 428 | fds.events = POLLIN; |
| 429 | if (poll (&fds, 1, 0) == 1 && (fds.revents & POLLNVAL)) |
| 430 | use_poll = 0; |
| 431 | #else |
| 432 | internal_error (__FILE__, __LINE__, |
| 433 | _("use_poll without HAVE_POLL")); |
| 434 | #endif /* HAVE_POLL */ |
| 435 | } |
| 436 | if (use_poll) |
| 437 | { |
| 438 | #ifdef HAVE_POLL |
| 439 | create_file_handler (fd, POLLIN, proc, client_data); |
| 440 | #else |
| 441 | internal_error (__FILE__, __LINE__, |
| 442 | _("use_poll without HAVE_POLL")); |
| 443 | #endif |
| 444 | } |
| 445 | else |
| 446 | create_file_handler (fd, GDB_READABLE | GDB_EXCEPTION, |
| 447 | proc, client_data); |
| 448 | } |
| 449 | |
| 450 | /* Add a file handler/descriptor to the list of descriptors we are |
| 451 | interested in. |
| 452 | |
| 453 | FD is the file descriptor for the file/stream to be listened to. |
| 454 | |
| 455 | For the poll case, MASK is a combination (OR) of POLLIN, |
| 456 | POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM, POLLWRBAND: |
| 457 | these are the events we are interested in. If any of them occurs, |
| 458 | proc should be called. |
| 459 | |
| 460 | For the select case, MASK is a combination of READABLE, WRITABLE, |
| 461 | EXCEPTION. PROC is the procedure that will be called when an event |
| 462 | occurs for FD. CLIENT_DATA is the argument to pass to PROC. */ |
| 463 | |
| 464 | static void |
| 465 | create_file_handler (int fd, int mask, handler_func * proc, |
| 466 | gdb_client_data client_data) |
| 467 | { |
| 468 | file_handler *file_ptr; |
| 469 | |
| 470 | /* Do we already have a file handler for this file? (We may be |
| 471 | changing its associated procedure). */ |
| 472 | for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; |
| 473 | file_ptr = file_ptr->next_file) |
| 474 | { |
| 475 | if (file_ptr->fd == fd) |
| 476 | break; |
| 477 | } |
| 478 | |
| 479 | /* It is a new file descriptor. Add it to the list. Otherwise, just |
| 480 | change the data associated with it. */ |
| 481 | if (file_ptr == NULL) |
| 482 | { |
| 483 | file_ptr = XNEW (file_handler); |
| 484 | file_ptr->fd = fd; |
| 485 | file_ptr->ready_mask = 0; |
| 486 | file_ptr->next_file = gdb_notifier.first_file_handler; |
| 487 | gdb_notifier.first_file_handler = file_ptr; |
| 488 | |
| 489 | if (use_poll) |
| 490 | { |
| 491 | #ifdef HAVE_POLL |
| 492 | gdb_notifier.num_fds++; |
| 493 | if (gdb_notifier.poll_fds) |
| 494 | gdb_notifier.poll_fds = |
| 495 | (struct pollfd *) xrealloc (gdb_notifier.poll_fds, |
| 496 | (gdb_notifier.num_fds |
| 497 | * sizeof (struct pollfd))); |
| 498 | else |
| 499 | gdb_notifier.poll_fds = |
| 500 | XNEW (struct pollfd); |
| 501 | (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->fd = fd; |
| 502 | (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->events = mask; |
| 503 | (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->revents = 0; |
| 504 | #else |
| 505 | internal_error (__FILE__, __LINE__, |
| 506 | _("use_poll without HAVE_POLL")); |
| 507 | #endif /* HAVE_POLL */ |
| 508 | } |
| 509 | else |
| 510 | { |
| 511 | if (mask & GDB_READABLE) |
| 512 | FD_SET (fd, &gdb_notifier.check_masks[0]); |
| 513 | else |
| 514 | FD_CLR (fd, &gdb_notifier.check_masks[0]); |
| 515 | |
| 516 | if (mask & GDB_WRITABLE) |
| 517 | FD_SET (fd, &gdb_notifier.check_masks[1]); |
| 518 | else |
| 519 | FD_CLR (fd, &gdb_notifier.check_masks[1]); |
| 520 | |
| 521 | if (mask & GDB_EXCEPTION) |
| 522 | FD_SET (fd, &gdb_notifier.check_masks[2]); |
| 523 | else |
| 524 | FD_CLR (fd, &gdb_notifier.check_masks[2]); |
| 525 | |
| 526 | if (gdb_notifier.num_fds <= fd) |
| 527 | gdb_notifier.num_fds = fd + 1; |
| 528 | } |
| 529 | } |
| 530 | |
| 531 | file_ptr->proc = proc; |
| 532 | file_ptr->client_data = client_data; |
| 533 | file_ptr->mask = mask; |
| 534 | } |
| 535 | |
| 536 | /* Return the next file handler to handle, and advance to the next |
| 537 | file handler, wrapping around if the end of the list is |
| 538 | reached. */ |
| 539 | |
| 540 | static file_handler * |
| 541 | get_next_file_handler_to_handle_and_advance (void) |
| 542 | { |
| 543 | file_handler *curr_next; |
| 544 | |
| 545 | /* The first time around, this is still NULL. */ |
| 546 | if (gdb_notifier.next_file_handler == NULL) |
| 547 | gdb_notifier.next_file_handler = gdb_notifier.first_file_handler; |
| 548 | |
| 549 | curr_next = gdb_notifier.next_file_handler; |
| 550 | gdb_assert (curr_next != NULL); |
| 551 | |
| 552 | /* Advance. */ |
| 553 | gdb_notifier.next_file_handler = curr_next->next_file; |
| 554 | /* Wrap around, if necessary. */ |
| 555 | if (gdb_notifier.next_file_handler == NULL) |
| 556 | gdb_notifier.next_file_handler = gdb_notifier.first_file_handler; |
| 557 | |
| 558 | return curr_next; |
| 559 | } |
| 560 | |
| 561 | /* Remove the file descriptor FD from the list of monitored fd's: |
| 562 | i.e. we don't care anymore about events on the FD. */ |
| 563 | void |
| 564 | delete_file_handler (int fd) |
| 565 | { |
| 566 | file_handler *file_ptr, *prev_ptr = NULL; |
| 567 | int i; |
| 568 | #ifdef HAVE_POLL |
| 569 | int j; |
| 570 | struct pollfd *new_poll_fds; |
| 571 | #endif |
| 572 | |
| 573 | /* Find the entry for the given file. */ |
| 574 | |
| 575 | for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; |
| 576 | file_ptr = file_ptr->next_file) |
| 577 | { |
| 578 | if (file_ptr->fd == fd) |
| 579 | break; |
| 580 | } |
| 581 | |
| 582 | if (file_ptr == NULL) |
| 583 | return; |
| 584 | |
| 585 | if (use_poll) |
| 586 | { |
| 587 | #ifdef HAVE_POLL |
| 588 | /* Create a new poll_fds array by copying every fd's information |
| 589 | but the one we want to get rid of. */ |
| 590 | |
| 591 | new_poll_fds = (struct pollfd *) |
| 592 | xmalloc ((gdb_notifier.num_fds - 1) * sizeof (struct pollfd)); |
| 593 | |
| 594 | for (i = 0, j = 0; i < gdb_notifier.num_fds; i++) |
| 595 | { |
| 596 | if ((gdb_notifier.poll_fds + i)->fd != fd) |
| 597 | { |
| 598 | (new_poll_fds + j)->fd = (gdb_notifier.poll_fds + i)->fd; |
| 599 | (new_poll_fds + j)->events = (gdb_notifier.poll_fds + i)->events; |
| 600 | (new_poll_fds + j)->revents |
| 601 | = (gdb_notifier.poll_fds + i)->revents; |
| 602 | j++; |
| 603 | } |
| 604 | } |
| 605 | xfree (gdb_notifier.poll_fds); |
| 606 | gdb_notifier.poll_fds = new_poll_fds; |
| 607 | gdb_notifier.num_fds--; |
| 608 | #else |
| 609 | internal_error (__FILE__, __LINE__, |
| 610 | _("use_poll without HAVE_POLL")); |
| 611 | #endif /* HAVE_POLL */ |
| 612 | } |
| 613 | else |
| 614 | { |
| 615 | if (file_ptr->mask & GDB_READABLE) |
| 616 | FD_CLR (fd, &gdb_notifier.check_masks[0]); |
| 617 | if (file_ptr->mask & GDB_WRITABLE) |
| 618 | FD_CLR (fd, &gdb_notifier.check_masks[1]); |
| 619 | if (file_ptr->mask & GDB_EXCEPTION) |
| 620 | FD_CLR (fd, &gdb_notifier.check_masks[2]); |
| 621 | |
| 622 | /* Find current max fd. */ |
| 623 | |
| 624 | if ((fd + 1) == gdb_notifier.num_fds) |
| 625 | { |
| 626 | gdb_notifier.num_fds--; |
| 627 | for (i = gdb_notifier.num_fds; i; i--) |
| 628 | { |
| 629 | if (FD_ISSET (i - 1, &gdb_notifier.check_masks[0]) |
| 630 | || FD_ISSET (i - 1, &gdb_notifier.check_masks[1]) |
| 631 | || FD_ISSET (i - 1, &gdb_notifier.check_masks[2])) |
| 632 | break; |
| 633 | } |
| 634 | gdb_notifier.num_fds = i; |
| 635 | } |
| 636 | } |
| 637 | |
| 638 | /* Deactivate the file descriptor, by clearing its mask, |
| 639 | so that it will not fire again. */ |
| 640 | |
| 641 | file_ptr->mask = 0; |
| 642 | |
| 643 | /* If this file handler was going to be the next one to be handled, |
| 644 | advance to the next's next, if any. */ |
| 645 | if (gdb_notifier.next_file_handler == file_ptr) |
| 646 | { |
| 647 | if (file_ptr->next_file == NULL |
| 648 | && file_ptr == gdb_notifier.first_file_handler) |
| 649 | gdb_notifier.next_file_handler = NULL; |
| 650 | else |
| 651 | get_next_file_handler_to_handle_and_advance (); |
| 652 | } |
| 653 | |
| 654 | /* Get rid of the file handler in the file handler list. */ |
| 655 | if (file_ptr == gdb_notifier.first_file_handler) |
| 656 | gdb_notifier.first_file_handler = file_ptr->next_file; |
| 657 | else |
| 658 | { |
| 659 | for (prev_ptr = gdb_notifier.first_file_handler; |
| 660 | prev_ptr->next_file != file_ptr; |
| 661 | prev_ptr = prev_ptr->next_file) |
| 662 | ; |
| 663 | prev_ptr->next_file = file_ptr->next_file; |
| 664 | } |
| 665 | xfree (file_ptr); |
| 666 | } |
| 667 | |
| 668 | /* Handle the given event by calling the procedure associated to the |
| 669 | corresponding file handler. */ |
| 670 | |
| 671 | static void |
| 672 | handle_file_event (file_handler *file_ptr, int ready_mask) |
| 673 | { |
| 674 | int mask; |
| 675 | #ifdef HAVE_POLL |
| 676 | int error_mask; |
| 677 | #endif |
| 678 | |
| 679 | { |
| 680 | { |
| 681 | /* With poll, the ready_mask could have any of three events |
| 682 | set to 1: POLLHUP, POLLERR, POLLNVAL. These events |
| 683 | cannot be used in the requested event mask (events), but |
| 684 | they can be returned in the return mask (revents). We |
| 685 | need to check for those event too, and add them to the |
| 686 | mask which will be passed to the handler. */ |
| 687 | |
| 688 | /* See if the desired events (mask) match the received |
| 689 | events (ready_mask). */ |
| 690 | |
| 691 | if (use_poll) |
| 692 | { |
| 693 | #ifdef HAVE_POLL |
| 694 | /* POLLHUP means EOF, but can be combined with POLLIN to |
| 695 | signal more data to read. */ |
| 696 | error_mask = POLLHUP | POLLERR | POLLNVAL; |
| 697 | mask = ready_mask & (file_ptr->mask | error_mask); |
| 698 | |
| 699 | if ((mask & (POLLERR | POLLNVAL)) != 0) |
| 700 | { |
| 701 | /* Work in progress. We may need to tell somebody |
| 702 | what kind of error we had. */ |
| 703 | if (mask & POLLERR) |
| 704 | printf_unfiltered (_("Error detected on fd %d\n"), |
| 705 | file_ptr->fd); |
| 706 | if (mask & POLLNVAL) |
| 707 | printf_unfiltered (_("Invalid or non-`poll'able fd %d\n"), |
| 708 | file_ptr->fd); |
| 709 | file_ptr->error = 1; |
| 710 | } |
| 711 | else |
| 712 | file_ptr->error = 0; |
| 713 | #else |
| 714 | internal_error (__FILE__, __LINE__, |
| 715 | _("use_poll without HAVE_POLL")); |
| 716 | #endif /* HAVE_POLL */ |
| 717 | } |
| 718 | else |
| 719 | { |
| 720 | if (ready_mask & GDB_EXCEPTION) |
| 721 | { |
| 722 | printf_unfiltered (_("Exception condition detected " |
| 723 | "on fd %d\n"), file_ptr->fd); |
| 724 | file_ptr->error = 1; |
| 725 | } |
| 726 | else |
| 727 | file_ptr->error = 0; |
| 728 | mask = ready_mask & file_ptr->mask; |
| 729 | } |
| 730 | |
| 731 | /* If there was a match, then call the handler. */ |
| 732 | if (mask != 0) |
| 733 | (*file_ptr->proc) (file_ptr->error, file_ptr->client_data); |
| 734 | } |
| 735 | } |
| 736 | } |
| 737 | |
| 738 | /* Wait for new events on the monitored file descriptors. Run the |
| 739 | event handler if the first descriptor that is detected by the poll. |
| 740 | If BLOCK and if there are no events, this function will block in |
| 741 | the call to poll. Return 1 if an event was handled. Return -1 if |
| 742 | there are no file descriptors to monitor. Return 1 if an event was |
| 743 | handled, otherwise returns 0. */ |
| 744 | |
| 745 | static int |
| 746 | gdb_wait_for_event (int block) |
| 747 | { |
| 748 | file_handler *file_ptr; |
| 749 | int num_found = 0; |
| 750 | |
| 751 | /* Make sure all output is done before getting another event. */ |
| 752 | gdb_flush (gdb_stdout); |
| 753 | gdb_flush (gdb_stderr); |
| 754 | |
| 755 | if (gdb_notifier.num_fds == 0) |
| 756 | return -1; |
| 757 | |
| 758 | if (block) |
| 759 | update_wait_timeout (); |
| 760 | |
| 761 | if (use_poll) |
| 762 | { |
| 763 | #ifdef HAVE_POLL |
| 764 | int timeout; |
| 765 | |
| 766 | if (block) |
| 767 | timeout = gdb_notifier.timeout_valid ? gdb_notifier.poll_timeout : -1; |
| 768 | else |
| 769 | timeout = 0; |
| 770 | |
| 771 | num_found = poll (gdb_notifier.poll_fds, |
| 772 | (unsigned long) gdb_notifier.num_fds, timeout); |
| 773 | |
| 774 | /* Don't print anything if we get out of poll because of a |
| 775 | signal. */ |
| 776 | if (num_found == -1 && errno != EINTR) |
| 777 | perror_with_name (("poll")); |
| 778 | #else |
| 779 | internal_error (__FILE__, __LINE__, |
| 780 | _("use_poll without HAVE_POLL")); |
| 781 | #endif /* HAVE_POLL */ |
| 782 | } |
| 783 | else |
| 784 | { |
| 785 | struct timeval select_timeout; |
| 786 | struct timeval *timeout_p; |
| 787 | |
| 788 | if (block) |
| 789 | timeout_p = gdb_notifier.timeout_valid |
| 790 | ? &gdb_notifier.select_timeout : NULL; |
| 791 | else |
| 792 | { |
| 793 | memset (&select_timeout, 0, sizeof (select_timeout)); |
| 794 | timeout_p = &select_timeout; |
| 795 | } |
| 796 | |
| 797 | gdb_notifier.ready_masks[0] = gdb_notifier.check_masks[0]; |
| 798 | gdb_notifier.ready_masks[1] = gdb_notifier.check_masks[1]; |
| 799 | gdb_notifier.ready_masks[2] = gdb_notifier.check_masks[2]; |
| 800 | num_found = gdb_select (gdb_notifier.num_fds, |
| 801 | &gdb_notifier.ready_masks[0], |
| 802 | &gdb_notifier.ready_masks[1], |
| 803 | &gdb_notifier.ready_masks[2], |
| 804 | timeout_p); |
| 805 | |
| 806 | /* Clear the masks after an error from select. */ |
| 807 | if (num_found == -1) |
| 808 | { |
| 809 | FD_ZERO (&gdb_notifier.ready_masks[0]); |
| 810 | FD_ZERO (&gdb_notifier.ready_masks[1]); |
| 811 | FD_ZERO (&gdb_notifier.ready_masks[2]); |
| 812 | |
| 813 | /* Dont print anything if we got a signal, let gdb handle |
| 814 | it. */ |
| 815 | if (errno != EINTR) |
| 816 | perror_with_name (("select")); |
| 817 | } |
| 818 | } |
| 819 | |
| 820 | /* Avoid looking at poll_fds[i]->revents if no event fired. */ |
| 821 | if (num_found <= 0) |
| 822 | return 0; |
| 823 | |
| 824 | /* Run event handlers. We always run just one handler and go back |
| 825 | to polling, in case a handler changes the notifier list. Since |
| 826 | events for sources we haven't consumed yet wake poll/select |
| 827 | immediately, no event is lost. */ |
| 828 | |
| 829 | /* To level the fairness across event descriptors, we handle them in |
| 830 | a round-robin-like fashion. The number and order of descriptors |
| 831 | may change between invocations, but this is good enough. */ |
| 832 | if (use_poll) |
| 833 | { |
| 834 | #ifdef HAVE_POLL |
| 835 | int i; |
| 836 | int mask; |
| 837 | |
| 838 | while (1) |
| 839 | { |
| 840 | if (gdb_notifier.next_poll_fds_index >= gdb_notifier.num_fds) |
| 841 | gdb_notifier.next_poll_fds_index = 0; |
| 842 | i = gdb_notifier.next_poll_fds_index++; |
| 843 | |
| 844 | gdb_assert (i < gdb_notifier.num_fds); |
| 845 | if ((gdb_notifier.poll_fds + i)->revents) |
| 846 | break; |
| 847 | } |
| 848 | |
| 849 | for (file_ptr = gdb_notifier.first_file_handler; |
| 850 | file_ptr != NULL; |
| 851 | file_ptr = file_ptr->next_file) |
| 852 | { |
| 853 | if (file_ptr->fd == (gdb_notifier.poll_fds + i)->fd) |
| 854 | break; |
| 855 | } |
| 856 | gdb_assert (file_ptr != NULL); |
| 857 | |
| 858 | mask = (gdb_notifier.poll_fds + i)->revents; |
| 859 | handle_file_event (file_ptr, mask); |
| 860 | return 1; |
| 861 | #else |
| 862 | internal_error (__FILE__, __LINE__, |
| 863 | _("use_poll without HAVE_POLL")); |
| 864 | #endif /* HAVE_POLL */ |
| 865 | } |
| 866 | else |
| 867 | { |
| 868 | /* See comment about even source fairness above. */ |
| 869 | int mask = 0; |
| 870 | |
| 871 | do |
| 872 | { |
| 873 | file_ptr = get_next_file_handler_to_handle_and_advance (); |
| 874 | |
| 875 | if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[0])) |
| 876 | mask |= GDB_READABLE; |
| 877 | if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[1])) |
| 878 | mask |= GDB_WRITABLE; |
| 879 | if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[2])) |
| 880 | mask |= GDB_EXCEPTION; |
| 881 | } |
| 882 | while (mask == 0); |
| 883 | |
| 884 | handle_file_event (file_ptr, mask); |
| 885 | return 1; |
| 886 | } |
| 887 | return 0; |
| 888 | } |
| 889 | \f |
| 890 | |
| 891 | /* Create an asynchronous handler, allocating memory for it. |
| 892 | Return a pointer to the newly created handler. |
| 893 | This pointer will be used to invoke the handler by |
| 894 | invoke_async_signal_handler. |
| 895 | PROC is the function to call with CLIENT_DATA argument |
| 896 | whenever the handler is invoked. */ |
| 897 | async_signal_handler * |
| 898 | create_async_signal_handler (sig_handler_func * proc, |
| 899 | gdb_client_data client_data) |
| 900 | { |
| 901 | async_signal_handler *async_handler_ptr; |
| 902 | |
| 903 | async_handler_ptr = XNEW (async_signal_handler); |
| 904 | async_handler_ptr->ready = 0; |
| 905 | async_handler_ptr->next_handler = NULL; |
| 906 | async_handler_ptr->proc = proc; |
| 907 | async_handler_ptr->client_data = client_data; |
| 908 | if (sighandler_list.first_handler == NULL) |
| 909 | sighandler_list.first_handler = async_handler_ptr; |
| 910 | else |
| 911 | sighandler_list.last_handler->next_handler = async_handler_ptr; |
| 912 | sighandler_list.last_handler = async_handler_ptr; |
| 913 | return async_handler_ptr; |
| 914 | } |
| 915 | |
| 916 | /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information |
| 917 | will be used when the handlers are invoked, after we have waited |
| 918 | for some event. The caller of this function is the interrupt |
| 919 | handler associated with a signal. */ |
| 920 | void |
| 921 | mark_async_signal_handler (async_signal_handler * async_handler_ptr) |
| 922 | { |
| 923 | async_handler_ptr->ready = 1; |
| 924 | serial_event_set (async_signal_handlers_serial_event); |
| 925 | } |
| 926 | |
| 927 | /* See event-loop.h. */ |
| 928 | |
| 929 | void |
| 930 | clear_async_signal_handler (async_signal_handler *async_handler_ptr) |
| 931 | { |
| 932 | async_handler_ptr->ready = 0; |
| 933 | } |
| 934 | |
| 935 | /* See event-loop.h. */ |
| 936 | |
| 937 | int |
| 938 | async_signal_handler_is_marked (async_signal_handler *async_handler_ptr) |
| 939 | { |
| 940 | return async_handler_ptr->ready; |
| 941 | } |
| 942 | |
| 943 | /* Call all the handlers that are ready. Returns true if any was |
| 944 | indeed ready. */ |
| 945 | |
| 946 | static int |
| 947 | invoke_async_signal_handlers (void) |
| 948 | { |
| 949 | async_signal_handler *async_handler_ptr; |
| 950 | int any_ready = 0; |
| 951 | |
| 952 | /* We're going to handle all pending signals, so no need to wake up |
| 953 | the event loop again the next time around. Note this must be |
| 954 | cleared _before_ calling the callbacks, to avoid races. */ |
| 955 | serial_event_clear (async_signal_handlers_serial_event); |
| 956 | |
| 957 | /* Invoke all ready handlers. */ |
| 958 | |
| 959 | while (1) |
| 960 | { |
| 961 | for (async_handler_ptr = sighandler_list.first_handler; |
| 962 | async_handler_ptr != NULL; |
| 963 | async_handler_ptr = async_handler_ptr->next_handler) |
| 964 | { |
| 965 | if (async_handler_ptr->ready) |
| 966 | break; |
| 967 | } |
| 968 | if (async_handler_ptr == NULL) |
| 969 | break; |
| 970 | any_ready = 1; |
| 971 | async_handler_ptr->ready = 0; |
| 972 | /* Async signal handlers have no connection to whichever was the |
| 973 | current UI, and thus always run on the main one. */ |
| 974 | current_ui = main_ui; |
| 975 | (*async_handler_ptr->proc) (async_handler_ptr->client_data); |
| 976 | } |
| 977 | |
| 978 | return any_ready; |
| 979 | } |
| 980 | |
| 981 | /* Delete an asynchronous handler (ASYNC_HANDLER_PTR). |
| 982 | Free the space allocated for it. */ |
| 983 | void |
| 984 | delete_async_signal_handler (async_signal_handler ** async_handler_ptr) |
| 985 | { |
| 986 | async_signal_handler *prev_ptr; |
| 987 | |
| 988 | if (sighandler_list.first_handler == (*async_handler_ptr)) |
| 989 | { |
| 990 | sighandler_list.first_handler = (*async_handler_ptr)->next_handler; |
| 991 | if (sighandler_list.first_handler == NULL) |
| 992 | sighandler_list.last_handler = NULL; |
| 993 | } |
| 994 | else |
| 995 | { |
| 996 | prev_ptr = sighandler_list.first_handler; |
| 997 | while (prev_ptr && prev_ptr->next_handler != (*async_handler_ptr)) |
| 998 | prev_ptr = prev_ptr->next_handler; |
| 999 | gdb_assert (prev_ptr); |
| 1000 | prev_ptr->next_handler = (*async_handler_ptr)->next_handler; |
| 1001 | if (sighandler_list.last_handler == (*async_handler_ptr)) |
| 1002 | sighandler_list.last_handler = prev_ptr; |
| 1003 | } |
| 1004 | xfree ((*async_handler_ptr)); |
| 1005 | (*async_handler_ptr) = NULL; |
| 1006 | } |
| 1007 | |
| 1008 | /* Create an asynchronous event handler, allocating memory for it. |
| 1009 | Return a pointer to the newly created handler. PROC is the |
| 1010 | function to call with CLIENT_DATA argument whenever the handler is |
| 1011 | invoked. */ |
| 1012 | async_event_handler * |
| 1013 | create_async_event_handler (async_event_handler_func *proc, |
| 1014 | gdb_client_data client_data) |
| 1015 | { |
| 1016 | async_event_handler *h; |
| 1017 | |
| 1018 | h = XNEW (struct async_event_handler); |
| 1019 | h->ready = 0; |
| 1020 | h->next_handler = NULL; |
| 1021 | h->proc = proc; |
| 1022 | h->client_data = client_data; |
| 1023 | if (async_event_handler_list.first_handler == NULL) |
| 1024 | async_event_handler_list.first_handler = h; |
| 1025 | else |
| 1026 | async_event_handler_list.last_handler->next_handler = h; |
| 1027 | async_event_handler_list.last_handler = h; |
| 1028 | return h; |
| 1029 | } |
| 1030 | |
| 1031 | /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information |
| 1032 | will be used by gdb_do_one_event. The caller will be whoever |
| 1033 | created the event source, and wants to signal that the event is |
| 1034 | ready to be handled. */ |
| 1035 | void |
| 1036 | mark_async_event_handler (async_event_handler *async_handler_ptr) |
| 1037 | { |
| 1038 | async_handler_ptr->ready = 1; |
| 1039 | } |
| 1040 | |
| 1041 | /* See event-loop.h. */ |
| 1042 | |
| 1043 | void |
| 1044 | clear_async_event_handler (async_event_handler *async_handler_ptr) |
| 1045 | { |
| 1046 | async_handler_ptr->ready = 0; |
| 1047 | } |
| 1048 | |
| 1049 | /* Check if asynchronous event handlers are ready, and call the |
| 1050 | handler function for one that is. */ |
| 1051 | |
| 1052 | static int |
| 1053 | check_async_event_handlers (void) |
| 1054 | { |
| 1055 | async_event_handler *async_handler_ptr; |
| 1056 | |
| 1057 | for (async_handler_ptr = async_event_handler_list.first_handler; |
| 1058 | async_handler_ptr != NULL; |
| 1059 | async_handler_ptr = async_handler_ptr->next_handler) |
| 1060 | { |
| 1061 | if (async_handler_ptr->ready) |
| 1062 | { |
| 1063 | async_handler_ptr->ready = 0; |
| 1064 | (*async_handler_ptr->proc) (async_handler_ptr->client_data); |
| 1065 | return 1; |
| 1066 | } |
| 1067 | } |
| 1068 | |
| 1069 | return 0; |
| 1070 | } |
| 1071 | |
| 1072 | /* Delete an asynchronous handler (ASYNC_HANDLER_PTR). |
| 1073 | Free the space allocated for it. */ |
| 1074 | void |
| 1075 | delete_async_event_handler (async_event_handler **async_handler_ptr) |
| 1076 | { |
| 1077 | async_event_handler *prev_ptr; |
| 1078 | |
| 1079 | if (async_event_handler_list.first_handler == *async_handler_ptr) |
| 1080 | { |
| 1081 | async_event_handler_list.first_handler |
| 1082 | = (*async_handler_ptr)->next_handler; |
| 1083 | if (async_event_handler_list.first_handler == NULL) |
| 1084 | async_event_handler_list.last_handler = NULL; |
| 1085 | } |
| 1086 | else |
| 1087 | { |
| 1088 | prev_ptr = async_event_handler_list.first_handler; |
| 1089 | while (prev_ptr && prev_ptr->next_handler != *async_handler_ptr) |
| 1090 | prev_ptr = prev_ptr->next_handler; |
| 1091 | gdb_assert (prev_ptr); |
| 1092 | prev_ptr->next_handler = (*async_handler_ptr)->next_handler; |
| 1093 | if (async_event_handler_list.last_handler == (*async_handler_ptr)) |
| 1094 | async_event_handler_list.last_handler = prev_ptr; |
| 1095 | } |
| 1096 | xfree (*async_handler_ptr); |
| 1097 | *async_handler_ptr = NULL; |
| 1098 | } |
| 1099 | |
| 1100 | /* Create a timer that will expire in MS milliseconds from now. When |
| 1101 | the timer is ready, PROC will be executed. At creation, the timer |
| 1102 | is added to the timers queue. This queue is kept sorted in order |
| 1103 | of increasing timers. Return a handle to the timer struct. */ |
| 1104 | |
| 1105 | int |
| 1106 | create_timer (int ms, timer_handler_func *proc, |
| 1107 | gdb_client_data client_data) |
| 1108 | { |
| 1109 | using namespace std::chrono; |
| 1110 | struct gdb_timer *timer_ptr, *timer_index, *prev_timer; |
| 1111 | |
| 1112 | steady_clock::time_point time_now = steady_clock::now (); |
| 1113 | |
| 1114 | timer_ptr = new gdb_timer (); |
| 1115 | timer_ptr->when = time_now + milliseconds (ms); |
| 1116 | timer_ptr->proc = proc; |
| 1117 | timer_ptr->client_data = client_data; |
| 1118 | timer_list.num_timers++; |
| 1119 | timer_ptr->timer_id = timer_list.num_timers; |
| 1120 | |
| 1121 | /* Now add the timer to the timer queue, making sure it is sorted in |
| 1122 | increasing order of expiration. */ |
| 1123 | |
| 1124 | for (timer_index = timer_list.first_timer; |
| 1125 | timer_index != NULL; |
| 1126 | timer_index = timer_index->next) |
| 1127 | { |
| 1128 | if (timer_index->when > timer_ptr->when) |
| 1129 | break; |
| 1130 | } |
| 1131 | |
| 1132 | if (timer_index == timer_list.first_timer) |
| 1133 | { |
| 1134 | timer_ptr->next = timer_list.first_timer; |
| 1135 | timer_list.first_timer = timer_ptr; |
| 1136 | |
| 1137 | } |
| 1138 | else |
| 1139 | { |
| 1140 | for (prev_timer = timer_list.first_timer; |
| 1141 | prev_timer->next != timer_index; |
| 1142 | prev_timer = prev_timer->next) |
| 1143 | ; |
| 1144 | |
| 1145 | prev_timer->next = timer_ptr; |
| 1146 | timer_ptr->next = timer_index; |
| 1147 | } |
| 1148 | |
| 1149 | gdb_notifier.timeout_valid = 0; |
| 1150 | return timer_ptr->timer_id; |
| 1151 | } |
| 1152 | |
| 1153 | /* There is a chance that the creator of the timer wants to get rid of |
| 1154 | it before it expires. */ |
| 1155 | void |
| 1156 | delete_timer (int id) |
| 1157 | { |
| 1158 | struct gdb_timer *timer_ptr, *prev_timer = NULL; |
| 1159 | |
| 1160 | /* Find the entry for the given timer. */ |
| 1161 | |
| 1162 | for (timer_ptr = timer_list.first_timer; timer_ptr != NULL; |
| 1163 | timer_ptr = timer_ptr->next) |
| 1164 | { |
| 1165 | if (timer_ptr->timer_id == id) |
| 1166 | break; |
| 1167 | } |
| 1168 | |
| 1169 | if (timer_ptr == NULL) |
| 1170 | return; |
| 1171 | /* Get rid of the timer in the timer list. */ |
| 1172 | if (timer_ptr == timer_list.first_timer) |
| 1173 | timer_list.first_timer = timer_ptr->next; |
| 1174 | else |
| 1175 | { |
| 1176 | for (prev_timer = timer_list.first_timer; |
| 1177 | prev_timer->next != timer_ptr; |
| 1178 | prev_timer = prev_timer->next) |
| 1179 | ; |
| 1180 | prev_timer->next = timer_ptr->next; |
| 1181 | } |
| 1182 | delete timer_ptr; |
| 1183 | |
| 1184 | gdb_notifier.timeout_valid = 0; |
| 1185 | } |
| 1186 | |
| 1187 | /* Convert a std::chrono duration to a struct timeval. */ |
| 1188 | |
| 1189 | template<typename Duration> |
| 1190 | static struct timeval |
| 1191 | duration_cast_timeval (const Duration &d) |
| 1192 | { |
| 1193 | using namespace std::chrono; |
| 1194 | seconds sec = duration_cast<seconds> (d); |
| 1195 | microseconds msec = duration_cast<microseconds> (d - sec); |
| 1196 | |
| 1197 | struct timeval tv; |
| 1198 | tv.tv_sec = sec.count (); |
| 1199 | tv.tv_usec = msec.count (); |
| 1200 | return tv; |
| 1201 | } |
| 1202 | |
| 1203 | /* Update the timeout for the select() or poll(). Returns true if the |
| 1204 | timer has already expired, false otherwise. */ |
| 1205 | |
| 1206 | static int |
| 1207 | update_wait_timeout (void) |
| 1208 | { |
| 1209 | if (timer_list.first_timer != NULL) |
| 1210 | { |
| 1211 | using namespace std::chrono; |
| 1212 | steady_clock::time_point time_now = steady_clock::now (); |
| 1213 | struct timeval timeout; |
| 1214 | |
| 1215 | if (timer_list.first_timer->when < time_now) |
| 1216 | { |
| 1217 | /* It expired already. */ |
| 1218 | timeout.tv_sec = 0; |
| 1219 | timeout.tv_usec = 0; |
| 1220 | } |
| 1221 | else |
| 1222 | { |
| 1223 | steady_clock::duration d = timer_list.first_timer->when - time_now; |
| 1224 | timeout = duration_cast_timeval (d); |
| 1225 | } |
| 1226 | |
| 1227 | /* Update the timeout for select/ poll. */ |
| 1228 | if (use_poll) |
| 1229 | { |
| 1230 | #ifdef HAVE_POLL |
| 1231 | gdb_notifier.poll_timeout = timeout.tv_sec * 1000; |
| 1232 | #else |
| 1233 | internal_error (__FILE__, __LINE__, |
| 1234 | _("use_poll without HAVE_POLL")); |
| 1235 | #endif /* HAVE_POLL */ |
| 1236 | } |
| 1237 | else |
| 1238 | { |
| 1239 | gdb_notifier.select_timeout.tv_sec = timeout.tv_sec; |
| 1240 | gdb_notifier.select_timeout.tv_usec = timeout.tv_usec; |
| 1241 | } |
| 1242 | gdb_notifier.timeout_valid = 1; |
| 1243 | |
| 1244 | if (timer_list.first_timer->when < time_now) |
| 1245 | return 1; |
| 1246 | } |
| 1247 | else |
| 1248 | gdb_notifier.timeout_valid = 0; |
| 1249 | |
| 1250 | return 0; |
| 1251 | } |
| 1252 | |
| 1253 | /* Check whether a timer in the timers queue is ready. If a timer is |
| 1254 | ready, call its handler and return. Update the timeout for the |
| 1255 | select() or poll() as well. Return 1 if an event was handled, |
| 1256 | otherwise returns 0.*/ |
| 1257 | |
| 1258 | static int |
| 1259 | poll_timers (void) |
| 1260 | { |
| 1261 | if (update_wait_timeout ()) |
| 1262 | { |
| 1263 | struct gdb_timer *timer_ptr = timer_list.first_timer; |
| 1264 | timer_handler_func *proc = timer_ptr->proc; |
| 1265 | gdb_client_data client_data = timer_ptr->client_data; |
| 1266 | |
| 1267 | /* Get rid of the timer from the beginning of the list. */ |
| 1268 | timer_list.first_timer = timer_ptr->next; |
| 1269 | |
| 1270 | /* Delete the timer before calling the callback, not after, in |
| 1271 | case the callback itself decides to try deleting the timer |
| 1272 | too. */ |
| 1273 | delete timer_ptr; |
| 1274 | |
| 1275 | /* Call the procedure associated with that timer. */ |
| 1276 | (proc) (client_data); |
| 1277 | |
| 1278 | return 1; |
| 1279 | } |
| 1280 | |
| 1281 | return 0; |
| 1282 | } |