| 1 | /* Event loop machinery for GDB, the GNU debugger. |
| 2 | Copyright (C) 1999, 2000, 2001, 2002, 2005, 2006, 2007, 2008, 2009, 2010, |
| 3 | 2011 Free Software Foundation, Inc. |
| 4 | Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions. |
| 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 | #include "defs.h" |
| 22 | #include "event-loop.h" |
| 23 | #include "event-top.h" |
| 24 | |
| 25 | #ifdef HAVE_POLL |
| 26 | #if defined (HAVE_POLL_H) |
| 27 | #include <poll.h> |
| 28 | #elif defined (HAVE_SYS_POLL_H) |
| 29 | #include <sys/poll.h> |
| 30 | #endif |
| 31 | #endif |
| 32 | |
| 33 | #include <sys/types.h> |
| 34 | #include "gdb_string.h" |
| 35 | #include <errno.h> |
| 36 | #include <sys/time.h> |
| 37 | #include "exceptions.h" |
| 38 | #include "gdb_assert.h" |
| 39 | #include "gdb_select.h" |
| 40 | |
| 41 | /* Tell create_file_handler what events we are interested in. |
| 42 | This is used by the select version of the event loop. */ |
| 43 | |
| 44 | #define GDB_READABLE (1<<1) |
| 45 | #define GDB_WRITABLE (1<<2) |
| 46 | #define GDB_EXCEPTION (1<<3) |
| 47 | |
| 48 | /* Data point to pass to the event handler. */ |
| 49 | typedef union event_data |
| 50 | { |
| 51 | void *ptr; |
| 52 | int integer; |
| 53 | } event_data; |
| 54 | |
| 55 | typedef struct gdb_event gdb_event; |
| 56 | typedef void (event_handler_func) (event_data); |
| 57 | |
| 58 | /* Event for the GDB event system. Events are queued by calling |
| 59 | async_queue_event and serviced later on by gdb_do_one_event. An |
| 60 | event can be, for instance, a file descriptor becoming ready to be |
| 61 | read. Servicing an event simply means that the procedure PROC will |
| 62 | be called. We have 2 queues, one for file handlers that we listen |
| 63 | to in the event loop, and one for the file handlers+events that are |
| 64 | ready. The procedure PROC associated with each event is dependant |
| 65 | of the event source. In the case of monitored file descriptors, it |
| 66 | is always the same (handle_file_event). Its duty is to invoke the |
| 67 | handler associated with the file descriptor whose state change |
| 68 | generated the event, plus doing other cleanups and such. In the |
| 69 | case of async signal handlers, it is |
| 70 | invoke_async_signal_handler. */ |
| 71 | |
| 72 | struct gdb_event |
| 73 | { |
| 74 | /* Procedure to call to service this event. */ |
| 75 | event_handler_func *proc; |
| 76 | |
| 77 | /* Data to pass to the event handler. */ |
| 78 | event_data data; |
| 79 | |
| 80 | /* Next in list of events or NULL. */ |
| 81 | struct gdb_event *next_event; |
| 82 | }; |
| 83 | |
| 84 | /* Information about each file descriptor we register with the event |
| 85 | loop. */ |
| 86 | |
| 87 | typedef struct file_handler |
| 88 | { |
| 89 | int fd; /* File descriptor. */ |
| 90 | int mask; /* Events we want to monitor: POLLIN, etc. */ |
| 91 | int ready_mask; /* Events that have been seen since |
| 92 | the last time. */ |
| 93 | handler_func *proc; /* Procedure to call when fd is ready. */ |
| 94 | gdb_client_data client_data; /* Argument to pass to proc. */ |
| 95 | int error; /* Was an error detected on this fd? */ |
| 96 | struct file_handler *next_file; /* Next registered file descriptor. */ |
| 97 | } |
| 98 | file_handler; |
| 99 | |
| 100 | /* PROC is a function to be invoked when the READY flag is set. This |
| 101 | happens when there has been a signal and the corresponding signal |
| 102 | handler has 'triggered' this async_signal_handler for execution. |
| 103 | The actual work to be done in response to a signal will be carried |
| 104 | out by PROC at a later time, within process_event. This provides a |
| 105 | deferred execution of signal handlers. |
| 106 | |
| 107 | Async_init_signals takes care of setting up such an |
| 108 | async_signal_handler for each interesting signal. */ |
| 109 | |
| 110 | typedef struct async_signal_handler |
| 111 | { |
| 112 | int ready; /* If ready, call this handler |
| 113 | from the main event loop, using |
| 114 | invoke_async_handler. */ |
| 115 | struct async_signal_handler *next_handler; /* Ptr to next handler. */ |
| 116 | sig_handler_func *proc; /* Function to call to do the work. */ |
| 117 | gdb_client_data client_data; /* Argument to async_handler_func. */ |
| 118 | } |
| 119 | async_signal_handler; |
| 120 | |
| 121 | /* PROC is a function to be invoked when the READY flag is set. This |
| 122 | happens when the event has been marked with |
| 123 | MARK_ASYNC_EVENT_HANDLER. The actual work to be done in response |
| 124 | to an event will be carried out by PROC at a later time, within |
| 125 | process_event. This provides a deferred execution of event |
| 126 | handlers. */ |
| 127 | typedef struct async_event_handler |
| 128 | { |
| 129 | /* If ready, call this handler from the main event loop, using |
| 130 | invoke_event_handler. */ |
| 131 | int ready; |
| 132 | |
| 133 | /* Point to next handler. */ |
| 134 | struct async_event_handler *next_handler; |
| 135 | |
| 136 | /* Function to call to do the work. */ |
| 137 | async_event_handler_func *proc; |
| 138 | |
| 139 | /* Argument to PROC. */ |
| 140 | gdb_client_data client_data; |
| 141 | } |
| 142 | async_event_handler; |
| 143 | |
| 144 | |
| 145 | /* Event queue: |
| 146 | - the first event in the queue is the head of the queue. |
| 147 | It will be the next to be serviced. |
| 148 | - the last event in the queue |
| 149 | |
| 150 | Events can be inserted at the front of the queue or at the end of |
| 151 | the queue. Events will be extracted from the queue for processing |
| 152 | starting from the head. Therefore, events inserted at the head of |
| 153 | the queue will be processed in a last in first out fashion, while |
| 154 | those inserted at the tail of the queue will be processed in a first |
| 155 | in first out manner. All the fields are NULL if the queue is |
| 156 | empty. */ |
| 157 | |
| 158 | static struct |
| 159 | { |
| 160 | gdb_event *first_event; /* First pending event. */ |
| 161 | gdb_event *last_event; /* Last pending event. */ |
| 162 | } |
| 163 | event_queue; |
| 164 | |
| 165 | /* Gdb_notifier is just a list of file descriptors gdb is interested in. |
| 166 | These are the input file descriptor, and the target file |
| 167 | descriptor. We have two flavors of the notifier, one for platforms |
| 168 | that have the POLL function, the other for those that don't, and |
| 169 | only support SELECT. Each of the elements in the gdb_notifier list is |
| 170 | basically a description of what kind of events gdb is interested |
| 171 | in, for each fd. */ |
| 172 | |
| 173 | /* As of 1999-04-30 only the input file descriptor is registered with the |
| 174 | event loop. */ |
| 175 | |
| 176 | /* Do we use poll or select ? */ |
| 177 | #ifdef HAVE_POLL |
| 178 | #define USE_POLL 1 |
| 179 | #else |
| 180 | #define USE_POLL 0 |
| 181 | #endif /* HAVE_POLL */ |
| 182 | |
| 183 | static unsigned char use_poll = USE_POLL; |
| 184 | |
| 185 | #ifdef USE_WIN32API |
| 186 | #include <windows.h> |
| 187 | #include <io.h> |
| 188 | #endif |
| 189 | |
| 190 | static struct |
| 191 | { |
| 192 | /* Ptr to head of file handler list. */ |
| 193 | file_handler *first_file_handler; |
| 194 | |
| 195 | #ifdef HAVE_POLL |
| 196 | /* Ptr to array of pollfd structures. */ |
| 197 | struct pollfd *poll_fds; |
| 198 | |
| 199 | /* Timeout in milliseconds for calls to poll(). */ |
| 200 | int poll_timeout; |
| 201 | #endif |
| 202 | |
| 203 | /* Masks to be used in the next call to select. |
| 204 | Bits are set in response to calls to create_file_handler. */ |
| 205 | fd_set check_masks[3]; |
| 206 | |
| 207 | /* What file descriptors were found ready by select. */ |
| 208 | fd_set ready_masks[3]; |
| 209 | |
| 210 | /* Number of file descriptors to monitor (for poll). */ |
| 211 | /* Number of valid bits (highest fd value + 1) (for select). */ |
| 212 | int num_fds; |
| 213 | |
| 214 | /* Time structure for calls to select(). */ |
| 215 | struct timeval select_timeout; |
| 216 | |
| 217 | /* Flag to tell whether the timeout should be used. */ |
| 218 | int timeout_valid; |
| 219 | } |
| 220 | gdb_notifier; |
| 221 | |
| 222 | /* Structure associated with a timer. PROC will be executed at the |
| 223 | first occasion after WHEN. */ |
| 224 | struct gdb_timer |
| 225 | { |
| 226 | struct timeval when; |
| 227 | int timer_id; |
| 228 | struct gdb_timer *next; |
| 229 | timer_handler_func *proc; /* Function to call to do the work. */ |
| 230 | gdb_client_data client_data; /* Argument to async_handler_func. */ |
| 231 | }; |
| 232 | |
| 233 | /* List of currently active timers. It is sorted in order of |
| 234 | increasing timers. */ |
| 235 | static struct |
| 236 | { |
| 237 | /* Pointer to first in timer list. */ |
| 238 | struct gdb_timer *first_timer; |
| 239 | |
| 240 | /* Id of the last timer created. */ |
| 241 | int num_timers; |
| 242 | } |
| 243 | timer_list; |
| 244 | |
| 245 | /* All the async_signal_handlers gdb is interested in are kept onto |
| 246 | this list. */ |
| 247 | static struct |
| 248 | { |
| 249 | /* Pointer to first in handler list. */ |
| 250 | async_signal_handler *first_handler; |
| 251 | |
| 252 | /* Pointer to last in handler list. */ |
| 253 | async_signal_handler *last_handler; |
| 254 | } |
| 255 | sighandler_list; |
| 256 | |
| 257 | /* All the async_event_handlers gdb is interested in are kept onto |
| 258 | this list. */ |
| 259 | static struct |
| 260 | { |
| 261 | /* Pointer to first in handler list. */ |
| 262 | async_event_handler *first_handler; |
| 263 | |
| 264 | /* Pointer to last in handler list. */ |
| 265 | async_event_handler *last_handler; |
| 266 | } |
| 267 | async_event_handler_list; |
| 268 | |
| 269 | static int invoke_async_signal_handlers (void); |
| 270 | static void create_file_handler (int fd, int mask, handler_func *proc, |
| 271 | gdb_client_data client_data); |
| 272 | static void handle_file_event (event_data data); |
| 273 | static void check_async_event_handlers (void); |
| 274 | static int gdb_wait_for_event (int); |
| 275 | static void poll_timers (void); |
| 276 | \f |
| 277 | |
| 278 | /* Insert an event object into the gdb event queue at |
| 279 | the specified position. |
| 280 | POSITION can be head or tail, with values TAIL, HEAD. |
| 281 | EVENT_PTR points to the event to be inserted into the queue. |
| 282 | The caller must allocate memory for the event. It is freed |
| 283 | after the event has ben handled. |
| 284 | Events in the queue will be processed head to tail, therefore, |
| 285 | events inserted at the head of the queue will be processed |
| 286 | as last in first out. Event appended at the tail of the queue |
| 287 | will be processed first in first out. */ |
| 288 | static void |
| 289 | async_queue_event (gdb_event * event_ptr, queue_position position) |
| 290 | { |
| 291 | if (position == TAIL) |
| 292 | { |
| 293 | /* The event will become the new last_event. */ |
| 294 | |
| 295 | event_ptr->next_event = NULL; |
| 296 | if (event_queue.first_event == NULL) |
| 297 | event_queue.first_event = event_ptr; |
| 298 | else |
| 299 | event_queue.last_event->next_event = event_ptr; |
| 300 | event_queue.last_event = event_ptr; |
| 301 | } |
| 302 | else if (position == HEAD) |
| 303 | { |
| 304 | /* The event becomes the new first_event. */ |
| 305 | |
| 306 | event_ptr->next_event = event_queue.first_event; |
| 307 | if (event_queue.first_event == NULL) |
| 308 | event_queue.last_event = event_ptr; |
| 309 | event_queue.first_event = event_ptr; |
| 310 | } |
| 311 | } |
| 312 | |
| 313 | /* Create a generic event, to be enqueued in the event queue for |
| 314 | processing. PROC is the procedure associated to the event. DATA |
| 315 | is passed to PROC upon PROC invocation. */ |
| 316 | |
| 317 | static gdb_event * |
| 318 | create_event (event_handler_func proc, event_data data) |
| 319 | { |
| 320 | gdb_event *event; |
| 321 | |
| 322 | event = xmalloc (sizeof (*event)); |
| 323 | event->proc = proc; |
| 324 | event->data = data; |
| 325 | |
| 326 | return event; |
| 327 | } |
| 328 | |
| 329 | /* Create a file event, to be enqueued in the event queue for |
| 330 | processing. The procedure associated to this event is always |
| 331 | handle_file_event, which will in turn invoke the one that was |
| 332 | associated to FD when it was registered with the event loop. */ |
| 333 | static gdb_event * |
| 334 | create_file_event (int fd) |
| 335 | { |
| 336 | event_data data; |
| 337 | |
| 338 | data.integer = fd; |
| 339 | return create_event (handle_file_event, data); |
| 340 | } |
| 341 | |
| 342 | /* Process one event. |
| 343 | The event can be the next one to be serviced in the event queue, |
| 344 | or an asynchronous event handler can be invoked in response to |
| 345 | the reception of a signal. |
| 346 | If an event was processed (either way), 1 is returned otherwise |
| 347 | 0 is returned. |
| 348 | Scan the queue from head to tail, processing therefore the high |
| 349 | priority events first, by invoking the associated event handler |
| 350 | procedure. */ |
| 351 | static int |
| 352 | process_event (void) |
| 353 | { |
| 354 | gdb_event *event_ptr, *prev_ptr; |
| 355 | event_handler_func *proc; |
| 356 | event_data data; |
| 357 | |
| 358 | /* First let's see if there are any asynchronous event handlers that |
| 359 | are ready. These would be the result of invoking any of the |
| 360 | signal handlers. */ |
| 361 | |
| 362 | if (invoke_async_signal_handlers ()) |
| 363 | return 1; |
| 364 | |
| 365 | /* Look in the event queue to find an event that is ready |
| 366 | to be processed. */ |
| 367 | |
| 368 | for (event_ptr = event_queue.first_event; event_ptr != NULL; |
| 369 | event_ptr = event_ptr->next_event) |
| 370 | { |
| 371 | /* Call the handler for the event. */ |
| 372 | |
| 373 | proc = event_ptr->proc; |
| 374 | data = event_ptr->data; |
| 375 | |
| 376 | /* Let's get rid of the event from the event queue. We need to |
| 377 | do this now because while processing the event, the proc |
| 378 | function could end up calling 'error' and therefore jump out |
| 379 | to the caller of this function, gdb_do_one_event. In that |
| 380 | case, we would have on the event queue an event wich has been |
| 381 | processed, but not deleted. */ |
| 382 | |
| 383 | if (event_queue.first_event == event_ptr) |
| 384 | { |
| 385 | event_queue.first_event = event_ptr->next_event; |
| 386 | if (event_ptr->next_event == NULL) |
| 387 | event_queue.last_event = NULL; |
| 388 | } |
| 389 | else |
| 390 | { |
| 391 | prev_ptr = event_queue.first_event; |
| 392 | while (prev_ptr->next_event != event_ptr) |
| 393 | prev_ptr = prev_ptr->next_event; |
| 394 | |
| 395 | prev_ptr->next_event = event_ptr->next_event; |
| 396 | if (event_ptr->next_event == NULL) |
| 397 | event_queue.last_event = prev_ptr; |
| 398 | } |
| 399 | xfree (event_ptr); |
| 400 | |
| 401 | /* Now call the procedure associated with the event. */ |
| 402 | (*proc) (data); |
| 403 | return 1; |
| 404 | } |
| 405 | |
| 406 | /* This is the case if there are no event on the event queue. */ |
| 407 | return 0; |
| 408 | } |
| 409 | |
| 410 | /* Process one high level event. If nothing is ready at this time, |
| 411 | wait for something to happen (via gdb_wait_for_event), then process |
| 412 | it. Returns >0 if something was done otherwise returns <0 (this |
| 413 | can happen if there are no event sources to wait for). */ |
| 414 | |
| 415 | int |
| 416 | gdb_do_one_event (void) |
| 417 | { |
| 418 | static int event_source_head = 0; |
| 419 | const int number_of_sources = 3; |
| 420 | int current = 0; |
| 421 | |
| 422 | /* Any events already waiting in the queue? */ |
| 423 | if (process_event ()) |
| 424 | return 1; |
| 425 | |
| 426 | /* To level the fairness across event sources, we poll them in a |
| 427 | round-robin fashion. */ |
| 428 | for (current = 0; current < number_of_sources; current++) |
| 429 | { |
| 430 | switch (event_source_head) |
| 431 | { |
| 432 | case 0: |
| 433 | /* Are any timers that are ready? If so, put an event on the |
| 434 | queue. */ |
| 435 | poll_timers (); |
| 436 | break; |
| 437 | case 1: |
| 438 | /* Are there events already waiting to be collected on the |
| 439 | monitored file descriptors? */ |
| 440 | gdb_wait_for_event (0); |
| 441 | break; |
| 442 | case 2: |
| 443 | /* Are there any asynchronous event handlers ready? */ |
| 444 | check_async_event_handlers (); |
| 445 | break; |
| 446 | } |
| 447 | |
| 448 | event_source_head++; |
| 449 | if (event_source_head == number_of_sources) |
| 450 | event_source_head = 0; |
| 451 | } |
| 452 | |
| 453 | /* Handle any new events collected. */ |
| 454 | if (process_event ()) |
| 455 | return 1; |
| 456 | |
| 457 | /* Block waiting for a new event. If gdb_wait_for_event returns -1, |
| 458 | we should get out because this means that there are no event |
| 459 | sources left. This will make the event loop stop, and the |
| 460 | application exit. */ |
| 461 | |
| 462 | if (gdb_wait_for_event (1) < 0) |
| 463 | return -1; |
| 464 | |
| 465 | /* Handle any new events occurred while waiting. */ |
| 466 | if (process_event ()) |
| 467 | return 1; |
| 468 | |
| 469 | /* If gdb_wait_for_event has returned 1, it means that one event has |
| 470 | been handled. We break out of the loop. */ |
| 471 | return 1; |
| 472 | } |
| 473 | |
| 474 | /* Start up the event loop. This is the entry point to the event loop |
| 475 | from the command loop. */ |
| 476 | |
| 477 | void |
| 478 | start_event_loop (void) |
| 479 | { |
| 480 | /* Loop until there is nothing to do. This is the entry point to |
| 481 | the event loop engine. gdb_do_one_event will process one event |
| 482 | for each invocation. It blocks waiting for an event and then |
| 483 | processes it. */ |
| 484 | while (1) |
| 485 | { |
| 486 | volatile struct gdb_exception ex; |
| 487 | int result = 0; |
| 488 | |
| 489 | TRY_CATCH (ex, RETURN_MASK_ALL) |
| 490 | { |
| 491 | result = gdb_do_one_event (); |
| 492 | } |
| 493 | if (ex.reason < 0) |
| 494 | { |
| 495 | exception_print (gdb_stderr, ex); |
| 496 | |
| 497 | /* If any exception escaped to here, we better enable |
| 498 | stdin. Otherwise, any command that calls async_disable_stdin, |
| 499 | and then throws, will leave stdin inoperable. */ |
| 500 | async_enable_stdin (); |
| 501 | /* If we long-jumped out of do_one_event, we probably didn't |
| 502 | get around to resetting the prompt, which leaves readline |
| 503 | in a messed-up state. Reset it here. */ |
| 504 | /* FIXME: this should really be a call to a hook that is |
| 505 | interface specific, because interfaces can display the |
| 506 | prompt in their own way. */ |
| 507 | display_gdb_prompt (0); |
| 508 | /* This call looks bizarre, but it is required. If the user |
| 509 | entered a command that caused an error, |
| 510 | after_char_processing_hook won't be called from |
| 511 | rl_callback_read_char_wrapper. Using a cleanup there |
| 512 | won't work, since we want this function to be called |
| 513 | after a new prompt is printed. */ |
| 514 | if (after_char_processing_hook) |
| 515 | (*after_char_processing_hook) (); |
| 516 | /* Maybe better to set a flag to be checked somewhere as to |
| 517 | whether display the prompt or not. */ |
| 518 | } |
| 519 | if (result < 0) |
| 520 | break; |
| 521 | } |
| 522 | |
| 523 | /* We are done with the event loop. There are no more event sources |
| 524 | to listen to. So we exit GDB. */ |
| 525 | return; |
| 526 | } |
| 527 | \f |
| 528 | |
| 529 | /* Wrapper function for create_file_handler, so that the caller |
| 530 | doesn't have to know implementation details about the use of poll |
| 531 | vs. select. */ |
| 532 | void |
| 533 | add_file_handler (int fd, handler_func * proc, gdb_client_data client_data) |
| 534 | { |
| 535 | #ifdef HAVE_POLL |
| 536 | struct pollfd fds; |
| 537 | #endif |
| 538 | |
| 539 | if (use_poll) |
| 540 | { |
| 541 | #ifdef HAVE_POLL |
| 542 | /* Check to see if poll () is usable. If not, we'll switch to |
| 543 | use select. This can happen on systems like |
| 544 | m68k-motorola-sys, `poll' cannot be used to wait for `stdin'. |
| 545 | On m68k-motorola-sysv, tty's are not stream-based and not |
| 546 | `poll'able. */ |
| 547 | fds.fd = fd; |
| 548 | fds.events = POLLIN; |
| 549 | if (poll (&fds, 1, 0) == 1 && (fds.revents & POLLNVAL)) |
| 550 | use_poll = 0; |
| 551 | #else |
| 552 | internal_error (__FILE__, __LINE__, |
| 553 | _("use_poll without HAVE_POLL")); |
| 554 | #endif /* HAVE_POLL */ |
| 555 | } |
| 556 | if (use_poll) |
| 557 | { |
| 558 | #ifdef HAVE_POLL |
| 559 | create_file_handler (fd, POLLIN, proc, client_data); |
| 560 | #else |
| 561 | internal_error (__FILE__, __LINE__, |
| 562 | _("use_poll without HAVE_POLL")); |
| 563 | #endif |
| 564 | } |
| 565 | else |
| 566 | create_file_handler (fd, GDB_READABLE | GDB_EXCEPTION, |
| 567 | proc, client_data); |
| 568 | } |
| 569 | |
| 570 | /* Add a file handler/descriptor to the list of descriptors we are |
| 571 | interested in. |
| 572 | |
| 573 | FD is the file descriptor for the file/stream to be listened to. |
| 574 | |
| 575 | For the poll case, MASK is a combination (OR) of POLLIN, |
| 576 | POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM, POLLWRBAND: |
| 577 | these are the events we are interested in. If any of them occurs, |
| 578 | proc should be called. |
| 579 | |
| 580 | For the select case, MASK is a combination of READABLE, WRITABLE, |
| 581 | EXCEPTION. PROC is the procedure that will be called when an event |
| 582 | occurs for FD. CLIENT_DATA is the argument to pass to PROC. */ |
| 583 | |
| 584 | static void |
| 585 | create_file_handler (int fd, int mask, handler_func * proc, |
| 586 | gdb_client_data client_data) |
| 587 | { |
| 588 | file_handler *file_ptr; |
| 589 | |
| 590 | /* Do we already have a file handler for this file? (We may be |
| 591 | changing its associated procedure). */ |
| 592 | for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; |
| 593 | file_ptr = file_ptr->next_file) |
| 594 | { |
| 595 | if (file_ptr->fd == fd) |
| 596 | break; |
| 597 | } |
| 598 | |
| 599 | /* It is a new file descriptor. Add it to the list. Otherwise, just |
| 600 | change the data associated with it. */ |
| 601 | if (file_ptr == NULL) |
| 602 | { |
| 603 | file_ptr = (file_handler *) xmalloc (sizeof (file_handler)); |
| 604 | file_ptr->fd = fd; |
| 605 | file_ptr->ready_mask = 0; |
| 606 | file_ptr->next_file = gdb_notifier.first_file_handler; |
| 607 | gdb_notifier.first_file_handler = file_ptr; |
| 608 | |
| 609 | if (use_poll) |
| 610 | { |
| 611 | #ifdef HAVE_POLL |
| 612 | gdb_notifier.num_fds++; |
| 613 | if (gdb_notifier.poll_fds) |
| 614 | gdb_notifier.poll_fds = |
| 615 | (struct pollfd *) xrealloc (gdb_notifier.poll_fds, |
| 616 | (gdb_notifier.num_fds |
| 617 | * sizeof (struct pollfd))); |
| 618 | else |
| 619 | gdb_notifier.poll_fds = |
| 620 | (struct pollfd *) xmalloc (sizeof (struct pollfd)); |
| 621 | (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->fd = fd; |
| 622 | (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->events = mask; |
| 623 | (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->revents = 0; |
| 624 | #else |
| 625 | internal_error (__FILE__, __LINE__, |
| 626 | _("use_poll without HAVE_POLL")); |
| 627 | #endif /* HAVE_POLL */ |
| 628 | } |
| 629 | else |
| 630 | { |
| 631 | if (mask & GDB_READABLE) |
| 632 | FD_SET (fd, &gdb_notifier.check_masks[0]); |
| 633 | else |
| 634 | FD_CLR (fd, &gdb_notifier.check_masks[0]); |
| 635 | |
| 636 | if (mask & GDB_WRITABLE) |
| 637 | FD_SET (fd, &gdb_notifier.check_masks[1]); |
| 638 | else |
| 639 | FD_CLR (fd, &gdb_notifier.check_masks[1]); |
| 640 | |
| 641 | if (mask & GDB_EXCEPTION) |
| 642 | FD_SET (fd, &gdb_notifier.check_masks[2]); |
| 643 | else |
| 644 | FD_CLR (fd, &gdb_notifier.check_masks[2]); |
| 645 | |
| 646 | if (gdb_notifier.num_fds <= fd) |
| 647 | gdb_notifier.num_fds = fd + 1; |
| 648 | } |
| 649 | } |
| 650 | |
| 651 | file_ptr->proc = proc; |
| 652 | file_ptr->client_data = client_data; |
| 653 | file_ptr->mask = mask; |
| 654 | } |
| 655 | |
| 656 | /* Remove the file descriptor FD from the list of monitored fd's: |
| 657 | i.e. we don't care anymore about events on the FD. */ |
| 658 | void |
| 659 | delete_file_handler (int fd) |
| 660 | { |
| 661 | file_handler *file_ptr, *prev_ptr = NULL; |
| 662 | int i; |
| 663 | #ifdef HAVE_POLL |
| 664 | int j; |
| 665 | struct pollfd *new_poll_fds; |
| 666 | #endif |
| 667 | |
| 668 | /* Find the entry for the given file. */ |
| 669 | |
| 670 | for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; |
| 671 | file_ptr = file_ptr->next_file) |
| 672 | { |
| 673 | if (file_ptr->fd == fd) |
| 674 | break; |
| 675 | } |
| 676 | |
| 677 | if (file_ptr == NULL) |
| 678 | return; |
| 679 | |
| 680 | if (use_poll) |
| 681 | { |
| 682 | #ifdef HAVE_POLL |
| 683 | /* Create a new poll_fds array by copying every fd's information |
| 684 | but the one we want to get rid of. */ |
| 685 | |
| 686 | new_poll_fds = (struct pollfd *) |
| 687 | xmalloc ((gdb_notifier.num_fds - 1) * sizeof (struct pollfd)); |
| 688 | |
| 689 | for (i = 0, j = 0; i < gdb_notifier.num_fds; i++) |
| 690 | { |
| 691 | if ((gdb_notifier.poll_fds + i)->fd != fd) |
| 692 | { |
| 693 | (new_poll_fds + j)->fd = (gdb_notifier.poll_fds + i)->fd; |
| 694 | (new_poll_fds + j)->events = (gdb_notifier.poll_fds + i)->events; |
| 695 | (new_poll_fds + j)->revents |
| 696 | = (gdb_notifier.poll_fds + i)->revents; |
| 697 | j++; |
| 698 | } |
| 699 | } |
| 700 | xfree (gdb_notifier.poll_fds); |
| 701 | gdb_notifier.poll_fds = new_poll_fds; |
| 702 | gdb_notifier.num_fds--; |
| 703 | #else |
| 704 | internal_error (__FILE__, __LINE__, |
| 705 | _("use_poll without HAVE_POLL")); |
| 706 | #endif /* HAVE_POLL */ |
| 707 | } |
| 708 | else |
| 709 | { |
| 710 | if (file_ptr->mask & GDB_READABLE) |
| 711 | FD_CLR (fd, &gdb_notifier.check_masks[0]); |
| 712 | if (file_ptr->mask & GDB_WRITABLE) |
| 713 | FD_CLR (fd, &gdb_notifier.check_masks[1]); |
| 714 | if (file_ptr->mask & GDB_EXCEPTION) |
| 715 | FD_CLR (fd, &gdb_notifier.check_masks[2]); |
| 716 | |
| 717 | /* Find current max fd. */ |
| 718 | |
| 719 | if ((fd + 1) == gdb_notifier.num_fds) |
| 720 | { |
| 721 | gdb_notifier.num_fds--; |
| 722 | for (i = gdb_notifier.num_fds; i; i--) |
| 723 | { |
| 724 | if (FD_ISSET (i - 1, &gdb_notifier.check_masks[0]) |
| 725 | || FD_ISSET (i - 1, &gdb_notifier.check_masks[1]) |
| 726 | || FD_ISSET (i - 1, &gdb_notifier.check_masks[2])) |
| 727 | break; |
| 728 | } |
| 729 | gdb_notifier.num_fds = i; |
| 730 | } |
| 731 | } |
| 732 | |
| 733 | /* Deactivate the file descriptor, by clearing its mask, |
| 734 | so that it will not fire again. */ |
| 735 | |
| 736 | file_ptr->mask = 0; |
| 737 | |
| 738 | /* Get rid of the file handler in the file handler list. */ |
| 739 | if (file_ptr == gdb_notifier.first_file_handler) |
| 740 | gdb_notifier.first_file_handler = file_ptr->next_file; |
| 741 | else |
| 742 | { |
| 743 | for (prev_ptr = gdb_notifier.first_file_handler; |
| 744 | prev_ptr->next_file != file_ptr; |
| 745 | prev_ptr = prev_ptr->next_file) |
| 746 | ; |
| 747 | prev_ptr->next_file = file_ptr->next_file; |
| 748 | } |
| 749 | xfree (file_ptr); |
| 750 | } |
| 751 | |
| 752 | /* Handle the given event by calling the procedure associated to the |
| 753 | corresponding file handler. Called by process_event indirectly, |
| 754 | through event_ptr->proc. EVENT_FILE_DESC is file descriptor of the |
| 755 | event in the front of the event queue. */ |
| 756 | static void |
| 757 | handle_file_event (event_data data) |
| 758 | { |
| 759 | file_handler *file_ptr; |
| 760 | int mask; |
| 761 | #ifdef HAVE_POLL |
| 762 | int error_mask; |
| 763 | #endif |
| 764 | int event_file_desc = data.integer; |
| 765 | |
| 766 | /* Search the file handler list to find one that matches the fd in |
| 767 | the event. */ |
| 768 | for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; |
| 769 | file_ptr = file_ptr->next_file) |
| 770 | { |
| 771 | if (file_ptr->fd == event_file_desc) |
| 772 | { |
| 773 | /* With poll, the ready_mask could have any of three events |
| 774 | set to 1: POLLHUP, POLLERR, POLLNVAL. These events |
| 775 | cannot be used in the requested event mask (events), but |
| 776 | they can be returned in the return mask (revents). We |
| 777 | need to check for those event too, and add them to the |
| 778 | mask which will be passed to the handler. */ |
| 779 | |
| 780 | /* See if the desired events (mask) match the received |
| 781 | events (ready_mask). */ |
| 782 | |
| 783 | if (use_poll) |
| 784 | { |
| 785 | #ifdef HAVE_POLL |
| 786 | /* POLLHUP means EOF, but can be combined with POLLIN to |
| 787 | signal more data to read. */ |
| 788 | error_mask = POLLHUP | POLLERR | POLLNVAL; |
| 789 | mask = file_ptr->ready_mask & (file_ptr->mask | error_mask); |
| 790 | |
| 791 | if ((mask & (POLLERR | POLLNVAL)) != 0) |
| 792 | { |
| 793 | /* Work in progress. We may need to tell somebody |
| 794 | what kind of error we had. */ |
| 795 | if (mask & POLLERR) |
| 796 | printf_unfiltered (_("Error detected on fd %d\n"), |
| 797 | file_ptr->fd); |
| 798 | if (mask & POLLNVAL) |
| 799 | printf_unfiltered (_("Invalid or non-`poll'able fd %d\n"), |
| 800 | file_ptr->fd); |
| 801 | file_ptr->error = 1; |
| 802 | } |
| 803 | else |
| 804 | file_ptr->error = 0; |
| 805 | #else |
| 806 | internal_error (__FILE__, __LINE__, |
| 807 | _("use_poll without HAVE_POLL")); |
| 808 | #endif /* HAVE_POLL */ |
| 809 | } |
| 810 | else |
| 811 | { |
| 812 | if (file_ptr->ready_mask & GDB_EXCEPTION) |
| 813 | { |
| 814 | printf_unfiltered (_("Exception condition detected " |
| 815 | "on fd %d\n"), file_ptr->fd); |
| 816 | file_ptr->error = 1; |
| 817 | } |
| 818 | else |
| 819 | file_ptr->error = 0; |
| 820 | mask = file_ptr->ready_mask & file_ptr->mask; |
| 821 | } |
| 822 | |
| 823 | /* Clear the received events for next time around. */ |
| 824 | file_ptr->ready_mask = 0; |
| 825 | |
| 826 | /* If there was a match, then call the handler. */ |
| 827 | if (mask != 0) |
| 828 | (*file_ptr->proc) (file_ptr->error, file_ptr->client_data); |
| 829 | break; |
| 830 | } |
| 831 | } |
| 832 | } |
| 833 | |
| 834 | /* Called by gdb_do_one_event to wait for new events on the monitored |
| 835 | file descriptors. Queue file events as they are detected by the |
| 836 | poll. If BLOCK and if there are no events, this function will |
| 837 | block in the call to poll. Return -1 if there are no file |
| 838 | descriptors to monitor, otherwise return 0. */ |
| 839 | static int |
| 840 | gdb_wait_for_event (int block) |
| 841 | { |
| 842 | file_handler *file_ptr; |
| 843 | gdb_event *file_event_ptr; |
| 844 | int num_found = 0; |
| 845 | int i; |
| 846 | |
| 847 | /* Make sure all output is done before getting another event. */ |
| 848 | gdb_flush (gdb_stdout); |
| 849 | gdb_flush (gdb_stderr); |
| 850 | |
| 851 | if (gdb_notifier.num_fds == 0) |
| 852 | return -1; |
| 853 | |
| 854 | if (use_poll) |
| 855 | { |
| 856 | #ifdef HAVE_POLL |
| 857 | int timeout; |
| 858 | |
| 859 | if (block) |
| 860 | timeout = gdb_notifier.timeout_valid ? gdb_notifier.poll_timeout : -1; |
| 861 | else |
| 862 | timeout = 0; |
| 863 | |
| 864 | num_found = poll (gdb_notifier.poll_fds, |
| 865 | (unsigned long) gdb_notifier.num_fds, timeout); |
| 866 | |
| 867 | /* Don't print anything if we get out of poll because of a |
| 868 | signal. */ |
| 869 | if (num_found == -1 && errno != EINTR) |
| 870 | perror_with_name (("poll")); |
| 871 | #else |
| 872 | internal_error (__FILE__, __LINE__, |
| 873 | _("use_poll without HAVE_POLL")); |
| 874 | #endif /* HAVE_POLL */ |
| 875 | } |
| 876 | else |
| 877 | { |
| 878 | struct timeval select_timeout; |
| 879 | struct timeval *timeout_p; |
| 880 | |
| 881 | if (block) |
| 882 | timeout_p = gdb_notifier.timeout_valid |
| 883 | ? &gdb_notifier.select_timeout : NULL; |
| 884 | else |
| 885 | { |
| 886 | memset (&select_timeout, 0, sizeof (select_timeout)); |
| 887 | timeout_p = &select_timeout; |
| 888 | } |
| 889 | |
| 890 | gdb_notifier.ready_masks[0] = gdb_notifier.check_masks[0]; |
| 891 | gdb_notifier.ready_masks[1] = gdb_notifier.check_masks[1]; |
| 892 | gdb_notifier.ready_masks[2] = gdb_notifier.check_masks[2]; |
| 893 | num_found = gdb_select (gdb_notifier.num_fds, |
| 894 | &gdb_notifier.ready_masks[0], |
| 895 | &gdb_notifier.ready_masks[1], |
| 896 | &gdb_notifier.ready_masks[2], |
| 897 | timeout_p); |
| 898 | |
| 899 | /* Clear the masks after an error from select. */ |
| 900 | if (num_found == -1) |
| 901 | { |
| 902 | FD_ZERO (&gdb_notifier.ready_masks[0]); |
| 903 | FD_ZERO (&gdb_notifier.ready_masks[1]); |
| 904 | FD_ZERO (&gdb_notifier.ready_masks[2]); |
| 905 | |
| 906 | /* Dont print anything if we got a signal, let gdb handle |
| 907 | it. */ |
| 908 | if (errno != EINTR) |
| 909 | perror_with_name (("select")); |
| 910 | } |
| 911 | } |
| 912 | |
| 913 | /* Enqueue all detected file events. */ |
| 914 | |
| 915 | if (use_poll) |
| 916 | { |
| 917 | #ifdef HAVE_POLL |
| 918 | for (i = 0; (i < gdb_notifier.num_fds) && (num_found > 0); i++) |
| 919 | { |
| 920 | if ((gdb_notifier.poll_fds + i)->revents) |
| 921 | num_found--; |
| 922 | else |
| 923 | continue; |
| 924 | |
| 925 | for (file_ptr = gdb_notifier.first_file_handler; |
| 926 | file_ptr != NULL; |
| 927 | file_ptr = file_ptr->next_file) |
| 928 | { |
| 929 | if (file_ptr->fd == (gdb_notifier.poll_fds + i)->fd) |
| 930 | break; |
| 931 | } |
| 932 | |
| 933 | if (file_ptr) |
| 934 | { |
| 935 | /* Enqueue an event only if this is still a new event for |
| 936 | this fd. */ |
| 937 | if (file_ptr->ready_mask == 0) |
| 938 | { |
| 939 | file_event_ptr = create_file_event (file_ptr->fd); |
| 940 | async_queue_event (file_event_ptr, TAIL); |
| 941 | } |
| 942 | file_ptr->ready_mask = (gdb_notifier.poll_fds + i)->revents; |
| 943 | } |
| 944 | } |
| 945 | #else |
| 946 | internal_error (__FILE__, __LINE__, |
| 947 | _("use_poll without HAVE_POLL")); |
| 948 | #endif /* HAVE_POLL */ |
| 949 | } |
| 950 | else |
| 951 | { |
| 952 | for (file_ptr = gdb_notifier.first_file_handler; |
| 953 | (file_ptr != NULL) && (num_found > 0); |
| 954 | file_ptr = file_ptr->next_file) |
| 955 | { |
| 956 | int mask = 0; |
| 957 | |
| 958 | if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[0])) |
| 959 | mask |= GDB_READABLE; |
| 960 | if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[1])) |
| 961 | mask |= GDB_WRITABLE; |
| 962 | if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[2])) |
| 963 | mask |= GDB_EXCEPTION; |
| 964 | |
| 965 | if (!mask) |
| 966 | continue; |
| 967 | else |
| 968 | num_found--; |
| 969 | |
| 970 | /* Enqueue an event only if this is still a new event for |
| 971 | this fd. */ |
| 972 | |
| 973 | if (file_ptr->ready_mask == 0) |
| 974 | { |
| 975 | file_event_ptr = create_file_event (file_ptr->fd); |
| 976 | async_queue_event (file_event_ptr, TAIL); |
| 977 | } |
| 978 | file_ptr->ready_mask = mask; |
| 979 | } |
| 980 | } |
| 981 | return 0; |
| 982 | } |
| 983 | \f |
| 984 | |
| 985 | /* Create an asynchronous handler, allocating memory for it. |
| 986 | Return a pointer to the newly created handler. |
| 987 | This pointer will be used to invoke the handler by |
| 988 | invoke_async_signal_handler. |
| 989 | PROC is the function to call with CLIENT_DATA argument |
| 990 | whenever the handler is invoked. */ |
| 991 | async_signal_handler * |
| 992 | create_async_signal_handler (sig_handler_func * proc, |
| 993 | gdb_client_data client_data) |
| 994 | { |
| 995 | async_signal_handler *async_handler_ptr; |
| 996 | |
| 997 | async_handler_ptr = |
| 998 | (async_signal_handler *) xmalloc (sizeof (async_signal_handler)); |
| 999 | async_handler_ptr->ready = 0; |
| 1000 | async_handler_ptr->next_handler = NULL; |
| 1001 | async_handler_ptr->proc = proc; |
| 1002 | async_handler_ptr->client_data = client_data; |
| 1003 | if (sighandler_list.first_handler == NULL) |
| 1004 | sighandler_list.first_handler = async_handler_ptr; |
| 1005 | else |
| 1006 | sighandler_list.last_handler->next_handler = async_handler_ptr; |
| 1007 | sighandler_list.last_handler = async_handler_ptr; |
| 1008 | return async_handler_ptr; |
| 1009 | } |
| 1010 | |
| 1011 | /* Call the handler from HANDLER immediately. This function runs |
| 1012 | signal handlers when returning to the event loop would be too |
| 1013 | slow. */ |
| 1014 | void |
| 1015 | call_async_signal_handler (struct async_signal_handler *handler) |
| 1016 | { |
| 1017 | (*handler->proc) (handler->client_data); |
| 1018 | } |
| 1019 | |
| 1020 | /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information |
| 1021 | will be used when the handlers are invoked, after we have waited |
| 1022 | for some event. The caller of this function is the interrupt |
| 1023 | handler associated with a signal. */ |
| 1024 | void |
| 1025 | mark_async_signal_handler (async_signal_handler * async_handler_ptr) |
| 1026 | { |
| 1027 | async_handler_ptr->ready = 1; |
| 1028 | } |
| 1029 | |
| 1030 | /* Call all the handlers that are ready. Returns true if any was |
| 1031 | indeed ready. */ |
| 1032 | static int |
| 1033 | invoke_async_signal_handlers (void) |
| 1034 | { |
| 1035 | async_signal_handler *async_handler_ptr; |
| 1036 | int any_ready = 0; |
| 1037 | |
| 1038 | /* Invoke ready handlers. */ |
| 1039 | |
| 1040 | while (1) |
| 1041 | { |
| 1042 | for (async_handler_ptr = sighandler_list.first_handler; |
| 1043 | async_handler_ptr != NULL; |
| 1044 | async_handler_ptr = async_handler_ptr->next_handler) |
| 1045 | { |
| 1046 | if (async_handler_ptr->ready) |
| 1047 | break; |
| 1048 | } |
| 1049 | if (async_handler_ptr == NULL) |
| 1050 | break; |
| 1051 | any_ready = 1; |
| 1052 | async_handler_ptr->ready = 0; |
| 1053 | (*async_handler_ptr->proc) (async_handler_ptr->client_data); |
| 1054 | } |
| 1055 | |
| 1056 | return any_ready; |
| 1057 | } |
| 1058 | |
| 1059 | /* Delete an asynchronous handler (ASYNC_HANDLER_PTR). |
| 1060 | Free the space allocated for it. */ |
| 1061 | void |
| 1062 | delete_async_signal_handler (async_signal_handler ** async_handler_ptr) |
| 1063 | { |
| 1064 | async_signal_handler *prev_ptr; |
| 1065 | |
| 1066 | if (sighandler_list.first_handler == (*async_handler_ptr)) |
| 1067 | { |
| 1068 | sighandler_list.first_handler = (*async_handler_ptr)->next_handler; |
| 1069 | if (sighandler_list.first_handler == NULL) |
| 1070 | sighandler_list.last_handler = NULL; |
| 1071 | } |
| 1072 | else |
| 1073 | { |
| 1074 | prev_ptr = sighandler_list.first_handler; |
| 1075 | while (prev_ptr && prev_ptr->next_handler != (*async_handler_ptr)) |
| 1076 | prev_ptr = prev_ptr->next_handler; |
| 1077 | gdb_assert (prev_ptr); |
| 1078 | prev_ptr->next_handler = (*async_handler_ptr)->next_handler; |
| 1079 | if (sighandler_list.last_handler == (*async_handler_ptr)) |
| 1080 | sighandler_list.last_handler = prev_ptr; |
| 1081 | } |
| 1082 | xfree ((*async_handler_ptr)); |
| 1083 | (*async_handler_ptr) = NULL; |
| 1084 | } |
| 1085 | |
| 1086 | /* Create an asynchronous event handler, allocating memory for it. |
| 1087 | Return a pointer to the newly created handler. PROC is the |
| 1088 | function to call with CLIENT_DATA argument whenever the handler is |
| 1089 | invoked. */ |
| 1090 | async_event_handler * |
| 1091 | create_async_event_handler (async_event_handler_func *proc, |
| 1092 | gdb_client_data client_data) |
| 1093 | { |
| 1094 | async_event_handler *h; |
| 1095 | |
| 1096 | h = xmalloc (sizeof (*h)); |
| 1097 | h->ready = 0; |
| 1098 | h->next_handler = NULL; |
| 1099 | h->proc = proc; |
| 1100 | h->client_data = client_data; |
| 1101 | if (async_event_handler_list.first_handler == NULL) |
| 1102 | async_event_handler_list.first_handler = h; |
| 1103 | else |
| 1104 | async_event_handler_list.last_handler->next_handler = h; |
| 1105 | async_event_handler_list.last_handler = h; |
| 1106 | return h; |
| 1107 | } |
| 1108 | |
| 1109 | /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information |
| 1110 | will be used by gdb_do_one_event. The caller will be whoever |
| 1111 | created the event source, and wants to signal that the event is |
| 1112 | ready to be handled. */ |
| 1113 | void |
| 1114 | mark_async_event_handler (async_event_handler *async_handler_ptr) |
| 1115 | { |
| 1116 | async_handler_ptr->ready = 1; |
| 1117 | } |
| 1118 | |
| 1119 | struct async_event_handler_data |
| 1120 | { |
| 1121 | async_event_handler_func* proc; |
| 1122 | gdb_client_data client_data; |
| 1123 | }; |
| 1124 | |
| 1125 | static void |
| 1126 | invoke_async_event_handler (event_data data) |
| 1127 | { |
| 1128 | struct async_event_handler_data *hdata = data.ptr; |
| 1129 | async_event_handler_func* proc = hdata->proc; |
| 1130 | gdb_client_data client_data = hdata->client_data; |
| 1131 | |
| 1132 | xfree (hdata); |
| 1133 | (*proc) (client_data); |
| 1134 | } |
| 1135 | |
| 1136 | /* Check if any asynchronous event handlers are ready, and queue |
| 1137 | events in the ready queue for any that are. */ |
| 1138 | static void |
| 1139 | check_async_event_handlers (void) |
| 1140 | { |
| 1141 | async_event_handler *async_handler_ptr; |
| 1142 | struct async_event_handler_data *hdata; |
| 1143 | struct gdb_event *event_ptr; |
| 1144 | event_data data; |
| 1145 | |
| 1146 | for (async_handler_ptr = async_event_handler_list.first_handler; |
| 1147 | async_handler_ptr != NULL; |
| 1148 | async_handler_ptr = async_handler_ptr->next_handler) |
| 1149 | { |
| 1150 | if (async_handler_ptr->ready) |
| 1151 | { |
| 1152 | async_handler_ptr->ready = 0; |
| 1153 | |
| 1154 | hdata = xmalloc (sizeof (*hdata)); |
| 1155 | |
| 1156 | hdata->proc = async_handler_ptr->proc; |
| 1157 | hdata->client_data = async_handler_ptr->client_data; |
| 1158 | |
| 1159 | data.ptr = hdata; |
| 1160 | |
| 1161 | event_ptr = create_event (invoke_async_event_handler, data); |
| 1162 | async_queue_event (event_ptr, TAIL); |
| 1163 | } |
| 1164 | } |
| 1165 | } |
| 1166 | |
| 1167 | /* Delete an asynchronous handler (ASYNC_HANDLER_PTR). |
| 1168 | Free the space allocated for it. */ |
| 1169 | void |
| 1170 | delete_async_event_handler (async_event_handler **async_handler_ptr) |
| 1171 | { |
| 1172 | async_event_handler *prev_ptr; |
| 1173 | |
| 1174 | if (async_event_handler_list.first_handler == *async_handler_ptr) |
| 1175 | { |
| 1176 | async_event_handler_list.first_handler |
| 1177 | = (*async_handler_ptr)->next_handler; |
| 1178 | if (async_event_handler_list.first_handler == NULL) |
| 1179 | async_event_handler_list.last_handler = NULL; |
| 1180 | } |
| 1181 | else |
| 1182 | { |
| 1183 | prev_ptr = async_event_handler_list.first_handler; |
| 1184 | while (prev_ptr && prev_ptr->next_handler != *async_handler_ptr) |
| 1185 | prev_ptr = prev_ptr->next_handler; |
| 1186 | gdb_assert (prev_ptr); |
| 1187 | prev_ptr->next_handler = (*async_handler_ptr)->next_handler; |
| 1188 | if (async_event_handler_list.last_handler == (*async_handler_ptr)) |
| 1189 | async_event_handler_list.last_handler = prev_ptr; |
| 1190 | } |
| 1191 | xfree (*async_handler_ptr); |
| 1192 | *async_handler_ptr = NULL; |
| 1193 | } |
| 1194 | |
| 1195 | /* Create a timer that will expire in MILLISECONDS from now. When the |
| 1196 | timer is ready, PROC will be executed. At creation, the timer is |
| 1197 | aded to the timers queue. This queue is kept sorted in order of |
| 1198 | increasing timers. Return a handle to the timer struct. */ |
| 1199 | int |
| 1200 | create_timer (int milliseconds, timer_handler_func * proc, |
| 1201 | gdb_client_data client_data) |
| 1202 | { |
| 1203 | struct gdb_timer *timer_ptr, *timer_index, *prev_timer; |
| 1204 | struct timeval time_now, delta; |
| 1205 | |
| 1206 | /* Compute seconds. */ |
| 1207 | delta.tv_sec = milliseconds / 1000; |
| 1208 | /* Compute microseconds. */ |
| 1209 | delta.tv_usec = (milliseconds % 1000) * 1000; |
| 1210 | |
| 1211 | gettimeofday (&time_now, NULL); |
| 1212 | |
| 1213 | timer_ptr = (struct gdb_timer *) xmalloc (sizeof (*timer_ptr)); |
| 1214 | timer_ptr->when.tv_sec = time_now.tv_sec + delta.tv_sec; |
| 1215 | timer_ptr->when.tv_usec = time_now.tv_usec + delta.tv_usec; |
| 1216 | /* Carry? */ |
| 1217 | if (timer_ptr->when.tv_usec >= 1000000) |
| 1218 | { |
| 1219 | timer_ptr->when.tv_sec += 1; |
| 1220 | timer_ptr->when.tv_usec -= 1000000; |
| 1221 | } |
| 1222 | timer_ptr->proc = proc; |
| 1223 | timer_ptr->client_data = client_data; |
| 1224 | timer_list.num_timers++; |
| 1225 | timer_ptr->timer_id = timer_list.num_timers; |
| 1226 | |
| 1227 | /* Now add the timer to the timer queue, making sure it is sorted in |
| 1228 | increasing order of expiration. */ |
| 1229 | |
| 1230 | for (timer_index = timer_list.first_timer; |
| 1231 | timer_index != NULL; |
| 1232 | timer_index = timer_index->next) |
| 1233 | { |
| 1234 | /* If the seconds field is greater or if it is the same, but the |
| 1235 | microsecond field is greater. */ |
| 1236 | if ((timer_index->when.tv_sec > timer_ptr->when.tv_sec) |
| 1237 | || ((timer_index->when.tv_sec == timer_ptr->when.tv_sec) |
| 1238 | && (timer_index->when.tv_usec > timer_ptr->when.tv_usec))) |
| 1239 | break; |
| 1240 | } |
| 1241 | |
| 1242 | if (timer_index == timer_list.first_timer) |
| 1243 | { |
| 1244 | timer_ptr->next = timer_list.first_timer; |
| 1245 | timer_list.first_timer = timer_ptr; |
| 1246 | |
| 1247 | } |
| 1248 | else |
| 1249 | { |
| 1250 | for (prev_timer = timer_list.first_timer; |
| 1251 | prev_timer->next != timer_index; |
| 1252 | prev_timer = prev_timer->next) |
| 1253 | ; |
| 1254 | |
| 1255 | prev_timer->next = timer_ptr; |
| 1256 | timer_ptr->next = timer_index; |
| 1257 | } |
| 1258 | |
| 1259 | gdb_notifier.timeout_valid = 0; |
| 1260 | return timer_ptr->timer_id; |
| 1261 | } |
| 1262 | |
| 1263 | /* There is a chance that the creator of the timer wants to get rid of |
| 1264 | it before it expires. */ |
| 1265 | void |
| 1266 | delete_timer (int id) |
| 1267 | { |
| 1268 | struct gdb_timer *timer_ptr, *prev_timer = NULL; |
| 1269 | |
| 1270 | /* Find the entry for the given timer. */ |
| 1271 | |
| 1272 | for (timer_ptr = timer_list.first_timer; timer_ptr != NULL; |
| 1273 | timer_ptr = timer_ptr->next) |
| 1274 | { |
| 1275 | if (timer_ptr->timer_id == id) |
| 1276 | break; |
| 1277 | } |
| 1278 | |
| 1279 | if (timer_ptr == NULL) |
| 1280 | return; |
| 1281 | /* Get rid of the timer in the timer list. */ |
| 1282 | if (timer_ptr == timer_list.first_timer) |
| 1283 | timer_list.first_timer = timer_ptr->next; |
| 1284 | else |
| 1285 | { |
| 1286 | for (prev_timer = timer_list.first_timer; |
| 1287 | prev_timer->next != timer_ptr; |
| 1288 | prev_timer = prev_timer->next) |
| 1289 | ; |
| 1290 | prev_timer->next = timer_ptr->next; |
| 1291 | } |
| 1292 | xfree (timer_ptr); |
| 1293 | |
| 1294 | gdb_notifier.timeout_valid = 0; |
| 1295 | } |
| 1296 | |
| 1297 | /* When a timer event is put on the event queue, it will be handled by |
| 1298 | this function. Just call the associated procedure and delete the |
| 1299 | timer event from the event queue. Repeat this for each timer that |
| 1300 | has expired. */ |
| 1301 | static void |
| 1302 | handle_timer_event (event_data dummy) |
| 1303 | { |
| 1304 | struct timeval time_now; |
| 1305 | struct gdb_timer *timer_ptr, *saved_timer; |
| 1306 | |
| 1307 | gettimeofday (&time_now, NULL); |
| 1308 | timer_ptr = timer_list.first_timer; |
| 1309 | |
| 1310 | while (timer_ptr != NULL) |
| 1311 | { |
| 1312 | if ((timer_ptr->when.tv_sec > time_now.tv_sec) |
| 1313 | || ((timer_ptr->when.tv_sec == time_now.tv_sec) |
| 1314 | && (timer_ptr->when.tv_usec > time_now.tv_usec))) |
| 1315 | break; |
| 1316 | |
| 1317 | /* Get rid of the timer from the beginning of the list. */ |
| 1318 | timer_list.first_timer = timer_ptr->next; |
| 1319 | saved_timer = timer_ptr; |
| 1320 | timer_ptr = timer_ptr->next; |
| 1321 | /* Call the procedure associated with that timer. */ |
| 1322 | (*saved_timer->proc) (saved_timer->client_data); |
| 1323 | xfree (saved_timer); |
| 1324 | } |
| 1325 | |
| 1326 | gdb_notifier.timeout_valid = 0; |
| 1327 | } |
| 1328 | |
| 1329 | /* Check whether any timers in the timers queue are ready. If at least |
| 1330 | one timer is ready, stick an event onto the event queue. Even in |
| 1331 | case more than one timer is ready, one event is enough, because the |
| 1332 | handle_timer_event() will go through the timers list and call the |
| 1333 | procedures associated with all that have expired.l Update the |
| 1334 | timeout for the select() or poll() as well. */ |
| 1335 | static void |
| 1336 | poll_timers (void) |
| 1337 | { |
| 1338 | struct timeval time_now, delta; |
| 1339 | gdb_event *event_ptr; |
| 1340 | |
| 1341 | if (timer_list.first_timer != NULL) |
| 1342 | { |
| 1343 | gettimeofday (&time_now, NULL); |
| 1344 | delta.tv_sec = timer_list.first_timer->when.tv_sec - time_now.tv_sec; |
| 1345 | delta.tv_usec = timer_list.first_timer->when.tv_usec - time_now.tv_usec; |
| 1346 | /* Borrow? */ |
| 1347 | if (delta.tv_usec < 0) |
| 1348 | { |
| 1349 | delta.tv_sec -= 1; |
| 1350 | delta.tv_usec += 1000000; |
| 1351 | } |
| 1352 | |
| 1353 | /* Oops it expired already. Tell select / poll to return |
| 1354 | immediately. (Cannot simply test if delta.tv_sec is negative |
| 1355 | because time_t might be unsigned.) */ |
| 1356 | if (timer_list.first_timer->when.tv_sec < time_now.tv_sec |
| 1357 | || (timer_list.first_timer->when.tv_sec == time_now.tv_sec |
| 1358 | && timer_list.first_timer->when.tv_usec < time_now.tv_usec)) |
| 1359 | { |
| 1360 | delta.tv_sec = 0; |
| 1361 | delta.tv_usec = 0; |
| 1362 | } |
| 1363 | |
| 1364 | if (delta.tv_sec == 0 && delta.tv_usec == 0) |
| 1365 | { |
| 1366 | event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event)); |
| 1367 | event_ptr->proc = handle_timer_event; |
| 1368 | event_ptr->data.integer = timer_list.first_timer->timer_id; |
| 1369 | async_queue_event (event_ptr, TAIL); |
| 1370 | } |
| 1371 | |
| 1372 | /* Now we need to update the timeout for select/ poll, because |
| 1373 | we don't want to sit there while this timer is expiring. */ |
| 1374 | if (use_poll) |
| 1375 | { |
| 1376 | #ifdef HAVE_POLL |
| 1377 | gdb_notifier.poll_timeout = delta.tv_sec * 1000; |
| 1378 | #else |
| 1379 | internal_error (__FILE__, __LINE__, |
| 1380 | _("use_poll without HAVE_POLL")); |
| 1381 | #endif /* HAVE_POLL */ |
| 1382 | } |
| 1383 | else |
| 1384 | { |
| 1385 | gdb_notifier.select_timeout.tv_sec = delta.tv_sec; |
| 1386 | gdb_notifier.select_timeout.tv_usec = delta.tv_usec; |
| 1387 | } |
| 1388 | gdb_notifier.timeout_valid = 1; |
| 1389 | } |
| 1390 | else |
| 1391 | gdb_notifier.timeout_valid = 0; |
| 1392 | } |