| 1 | /* Event loop machinery for GDB, the GNU debugger. |
| 2 | Copyright (C) 1999, 2000, 2001, 2002, 2005, 2006 |
| 3 | 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 2 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, write to the Free Software |
| 20 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| 21 | Boston, MA 02110-1301, USA. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "event-loop.h" |
| 25 | #include "event-top.h" |
| 26 | |
| 27 | #ifdef HAVE_POLL |
| 28 | #if defined (HAVE_POLL_H) |
| 29 | #include <poll.h> |
| 30 | #elif defined (HAVE_SYS_POLL_H) |
| 31 | #include <sys/poll.h> |
| 32 | #endif |
| 33 | #endif |
| 34 | |
| 35 | #include <sys/types.h> |
| 36 | #include "gdb_string.h" |
| 37 | #include <errno.h> |
| 38 | #include <sys/time.h> |
| 39 | #include "exceptions.h" |
| 40 | #include "gdb_assert.h" |
| 41 | #include "gdb_select.h" |
| 42 | |
| 43 | typedef struct gdb_event gdb_event; |
| 44 | typedef void (event_handler_func) (int); |
| 45 | |
| 46 | /* Event for the GDB event system. Events are queued by calling |
| 47 | async_queue_event and serviced later on by gdb_do_one_event. An |
| 48 | event can be, for instance, a file descriptor becoming ready to be |
| 49 | read. Servicing an event simply means that the procedure PROC will |
| 50 | be called. We have 2 queues, one for file handlers that we listen |
| 51 | to in the event loop, and one for the file handlers+events that are |
| 52 | ready. The procedure PROC associated with each event is always the |
| 53 | same (handle_file_event). Its duty is to invoke the handler |
| 54 | associated with the file descriptor whose state change generated |
| 55 | the event, plus doing other cleanups and such. */ |
| 56 | |
| 57 | struct gdb_event |
| 58 | { |
| 59 | event_handler_func *proc; /* Procedure to call to service this event. */ |
| 60 | int fd; /* File descriptor that is ready. */ |
| 61 | struct gdb_event *next_event; /* Next in list of events or NULL. */ |
| 62 | }; |
| 63 | |
| 64 | /* Information about each file descriptor we register with the event |
| 65 | loop. */ |
| 66 | |
| 67 | typedef struct file_handler |
| 68 | { |
| 69 | int fd; /* File descriptor. */ |
| 70 | int mask; /* Events we want to monitor: POLLIN, etc. */ |
| 71 | int ready_mask; /* Events that have been seen since |
| 72 | the last time. */ |
| 73 | handler_func *proc; /* Procedure to call when fd is ready. */ |
| 74 | gdb_client_data client_data; /* Argument to pass to proc. */ |
| 75 | int error; /* Was an error detected on this fd? */ |
| 76 | struct file_handler *next_file; /* Next registered file descriptor. */ |
| 77 | } |
| 78 | file_handler; |
| 79 | |
| 80 | /* PROC is a function to be invoked when the READY flag is set. This |
| 81 | happens when there has been a signal and the corresponding signal |
| 82 | handler has 'triggered' this async_signal_handler for |
| 83 | execution. The actual work to be done in response to a signal will |
| 84 | be carried out by PROC at a later time, within process_event. This |
| 85 | provides a deferred execution of signal handlers. |
| 86 | Async_init_signals takes care of setting up such an |
| 87 | asyn_signal_handler for each interesting signal. */ |
| 88 | typedef struct async_signal_handler |
| 89 | { |
| 90 | int ready; /* If ready, call this handler from the main event loop, |
| 91 | using invoke_async_handler. */ |
| 92 | struct async_signal_handler *next_handler; /* Ptr to next handler */ |
| 93 | sig_handler_func *proc; /* Function to call to do the work */ |
| 94 | gdb_client_data client_data; /* Argument to async_handler_func */ |
| 95 | } |
| 96 | async_signal_handler; |
| 97 | |
| 98 | |
| 99 | /* Event queue: |
| 100 | - the first event in the queue is the head of the queue. |
| 101 | It will be the next to be serviced. |
| 102 | - the last event in the queue |
| 103 | |
| 104 | Events can be inserted at the front of the queue or at the end of |
| 105 | the queue. Events will be extracted from the queue for processing |
| 106 | starting from the head. Therefore, events inserted at the head of |
| 107 | the queue will be processed in a last in first out fashion, while |
| 108 | those inserted at the tail of the queue will be processed in a first |
| 109 | in first out manner. All the fields are NULL if the queue is |
| 110 | empty. */ |
| 111 | |
| 112 | static struct |
| 113 | { |
| 114 | gdb_event *first_event; /* First pending event */ |
| 115 | gdb_event *last_event; /* Last pending event */ |
| 116 | } |
| 117 | event_queue; |
| 118 | |
| 119 | /* Gdb_notifier is just a list of file descriptors gdb is interested in. |
| 120 | These are the input file descriptor, and the target file |
| 121 | descriptor. We have two flavors of the notifier, one for platforms |
| 122 | that have the POLL function, the other for those that don't, and |
| 123 | only support SELECT. Each of the elements in the gdb_notifier list is |
| 124 | basically a description of what kind of events gdb is interested |
| 125 | in, for each fd. */ |
| 126 | |
| 127 | /* As of 1999-04-30 only the input file descriptor is registered with the |
| 128 | event loop. */ |
| 129 | |
| 130 | /* Do we use poll or select ? */ |
| 131 | #ifdef HAVE_POLL |
| 132 | #define USE_POLL 1 |
| 133 | #else |
| 134 | #define USE_POLL 0 |
| 135 | #endif /* HAVE_POLL */ |
| 136 | |
| 137 | static unsigned char use_poll = USE_POLL; |
| 138 | |
| 139 | #ifdef USE_WIN32API |
| 140 | #include <windows.h> |
| 141 | #include <io.h> |
| 142 | #endif |
| 143 | |
| 144 | static struct |
| 145 | { |
| 146 | /* Ptr to head of file handler list. */ |
| 147 | file_handler *first_file_handler; |
| 148 | |
| 149 | #ifdef HAVE_POLL |
| 150 | /* Ptr to array of pollfd structures. */ |
| 151 | struct pollfd *poll_fds; |
| 152 | |
| 153 | /* Timeout in milliseconds for calls to poll(). */ |
| 154 | int poll_timeout; |
| 155 | #endif |
| 156 | |
| 157 | /* Masks to be used in the next call to select. |
| 158 | Bits are set in response to calls to create_file_handler. */ |
| 159 | fd_set check_masks[3]; |
| 160 | |
| 161 | /* What file descriptors were found ready by select. */ |
| 162 | fd_set ready_masks[3]; |
| 163 | |
| 164 | /* Number of file descriptors to monitor. (for poll) */ |
| 165 | /* Number of valid bits (highest fd value + 1). (for select) */ |
| 166 | int num_fds; |
| 167 | |
| 168 | /* Time structure for calls to select(). */ |
| 169 | struct timeval select_timeout; |
| 170 | |
| 171 | /* Flag to tell whether the timeout should be used. */ |
| 172 | int timeout_valid; |
| 173 | } |
| 174 | gdb_notifier; |
| 175 | |
| 176 | /* Structure associated with a timer. PROC will be executed at the |
| 177 | first occasion after WHEN. */ |
| 178 | struct gdb_timer |
| 179 | { |
| 180 | struct timeval when; |
| 181 | int timer_id; |
| 182 | struct gdb_timer *next; |
| 183 | timer_handler_func *proc; /* Function to call to do the work */ |
| 184 | gdb_client_data client_data; /* Argument to async_handler_func */ |
| 185 | } |
| 186 | gdb_timer; |
| 187 | |
| 188 | /* List of currently active timers. It is sorted in order of |
| 189 | increasing timers. */ |
| 190 | static struct |
| 191 | { |
| 192 | /* Pointer to first in timer list. */ |
| 193 | struct gdb_timer *first_timer; |
| 194 | |
| 195 | /* Id of the last timer created. */ |
| 196 | int num_timers; |
| 197 | } |
| 198 | timer_list; |
| 199 | |
| 200 | /* All the async_signal_handlers gdb is interested in are kept onto |
| 201 | this list. */ |
| 202 | static struct |
| 203 | { |
| 204 | /* Pointer to first in handler list. */ |
| 205 | async_signal_handler *first_handler; |
| 206 | |
| 207 | /* Pointer to last in handler list. */ |
| 208 | async_signal_handler *last_handler; |
| 209 | } |
| 210 | sighandler_list; |
| 211 | |
| 212 | /* Are any of the handlers ready? Check this variable using |
| 213 | check_async_ready. This is used by process_event, to determine |
| 214 | whether or not to invoke the invoke_async_signal_handler |
| 215 | function. */ |
| 216 | static int async_handler_ready = 0; |
| 217 | |
| 218 | static void create_file_handler (int fd, int mask, handler_func * proc, gdb_client_data client_data); |
| 219 | static void invoke_async_signal_handler (void); |
| 220 | static void handle_file_event (int event_file_desc); |
| 221 | static int gdb_wait_for_event (void); |
| 222 | static int check_async_ready (void); |
| 223 | static void async_queue_event (gdb_event * event_ptr, queue_position position); |
| 224 | static gdb_event *create_file_event (int fd); |
| 225 | static int process_event (void); |
| 226 | static void handle_timer_event (int dummy); |
| 227 | static void poll_timers (void); |
| 228 | \f |
| 229 | |
| 230 | /* Insert an event object into the gdb event queue at |
| 231 | the specified position. |
| 232 | POSITION can be head or tail, with values TAIL, HEAD. |
| 233 | EVENT_PTR points to the event to be inserted into the queue. |
| 234 | The caller must allocate memory for the event. It is freed |
| 235 | after the event has ben handled. |
| 236 | Events in the queue will be processed head to tail, therefore, |
| 237 | events inserted at the head of the queue will be processed |
| 238 | as last in first out. Event appended at the tail of the queue |
| 239 | will be processed first in first out. */ |
| 240 | static void |
| 241 | async_queue_event (gdb_event * event_ptr, queue_position position) |
| 242 | { |
| 243 | if (position == TAIL) |
| 244 | { |
| 245 | /* The event will become the new last_event. */ |
| 246 | |
| 247 | event_ptr->next_event = NULL; |
| 248 | if (event_queue.first_event == NULL) |
| 249 | event_queue.first_event = event_ptr; |
| 250 | else |
| 251 | event_queue.last_event->next_event = event_ptr; |
| 252 | event_queue.last_event = event_ptr; |
| 253 | } |
| 254 | else if (position == HEAD) |
| 255 | { |
| 256 | /* The event becomes the new first_event. */ |
| 257 | |
| 258 | event_ptr->next_event = event_queue.first_event; |
| 259 | if (event_queue.first_event == NULL) |
| 260 | event_queue.last_event = event_ptr; |
| 261 | event_queue.first_event = event_ptr; |
| 262 | } |
| 263 | } |
| 264 | |
| 265 | /* Create a file event, to be enqueued in the event queue for |
| 266 | processing. The procedure associated to this event is always |
| 267 | handle_file_event, which will in turn invoke the one that was |
| 268 | associated to FD when it was registered with the event loop. */ |
| 269 | static gdb_event * |
| 270 | create_file_event (int fd) |
| 271 | { |
| 272 | gdb_event *file_event_ptr; |
| 273 | |
| 274 | file_event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event)); |
| 275 | file_event_ptr->proc = handle_file_event; |
| 276 | file_event_ptr->fd = fd; |
| 277 | return (file_event_ptr); |
| 278 | } |
| 279 | |
| 280 | /* Process one event. |
| 281 | The event can be the next one to be serviced in the event queue, |
| 282 | or an asynchronous event handler can be invoked in response to |
| 283 | the reception of a signal. |
| 284 | If an event was processed (either way), 1 is returned otherwise |
| 285 | 0 is returned. |
| 286 | Scan the queue from head to tail, processing therefore the high |
| 287 | priority events first, by invoking the associated event handler |
| 288 | procedure. */ |
| 289 | static int |
| 290 | process_event (void) |
| 291 | { |
| 292 | gdb_event *event_ptr, *prev_ptr; |
| 293 | event_handler_func *proc; |
| 294 | int fd; |
| 295 | |
| 296 | /* First let's see if there are any asynchronous event handlers that |
| 297 | are ready. These would be the result of invoking any of the |
| 298 | signal handlers. */ |
| 299 | |
| 300 | if (check_async_ready ()) |
| 301 | { |
| 302 | invoke_async_signal_handler (); |
| 303 | return 1; |
| 304 | } |
| 305 | |
| 306 | /* Look in the event queue to find an event that is ready |
| 307 | to be processed. */ |
| 308 | |
| 309 | for (event_ptr = event_queue.first_event; event_ptr != NULL; |
| 310 | event_ptr = event_ptr->next_event) |
| 311 | { |
| 312 | /* Call the handler for the event. */ |
| 313 | |
| 314 | proc = event_ptr->proc; |
| 315 | fd = event_ptr->fd; |
| 316 | |
| 317 | /* Let's get rid of the event from the event queue. We need to |
| 318 | do this now because while processing the event, the proc |
| 319 | function could end up calling 'error' and therefore jump out |
| 320 | to the caller of this function, gdb_do_one_event. In that |
| 321 | case, we would have on the event queue an event wich has been |
| 322 | processed, but not deleted. */ |
| 323 | |
| 324 | if (event_queue.first_event == event_ptr) |
| 325 | { |
| 326 | event_queue.first_event = event_ptr->next_event; |
| 327 | if (event_ptr->next_event == NULL) |
| 328 | event_queue.last_event = NULL; |
| 329 | } |
| 330 | else |
| 331 | { |
| 332 | prev_ptr = event_queue.first_event; |
| 333 | while (prev_ptr->next_event != event_ptr) |
| 334 | prev_ptr = prev_ptr->next_event; |
| 335 | |
| 336 | prev_ptr->next_event = event_ptr->next_event; |
| 337 | if (event_ptr->next_event == NULL) |
| 338 | event_queue.last_event = prev_ptr; |
| 339 | } |
| 340 | xfree (event_ptr); |
| 341 | |
| 342 | /* Now call the procedure associated with the event. */ |
| 343 | (*proc) (fd); |
| 344 | return 1; |
| 345 | } |
| 346 | |
| 347 | /* this is the case if there are no event on the event queue. */ |
| 348 | return 0; |
| 349 | } |
| 350 | |
| 351 | /* Process one high level event. If nothing is ready at this time, |
| 352 | wait for something to happen (via gdb_wait_for_event), then process |
| 353 | it. Returns >0 if something was done otherwise returns <0 (this |
| 354 | can happen if there are no event sources to wait for). If an error |
| 355 | occurs catch_errors() which calls this function returns zero. */ |
| 356 | |
| 357 | int |
| 358 | gdb_do_one_event (void *data) |
| 359 | { |
| 360 | /* Any events already waiting in the queue? */ |
| 361 | if (process_event ()) |
| 362 | { |
| 363 | return 1; |
| 364 | } |
| 365 | |
| 366 | /* Are any timers that are ready? If so, put an event on the queue. */ |
| 367 | poll_timers (); |
| 368 | |
| 369 | /* Wait for a new event. If gdb_wait_for_event returns -1, |
| 370 | we should get out because this means that there are no |
| 371 | event sources left. This will make the event loop stop, |
| 372 | and the application exit. */ |
| 373 | |
| 374 | if (gdb_wait_for_event () < 0) |
| 375 | { |
| 376 | return -1; |
| 377 | } |
| 378 | |
| 379 | /* Handle any new events occurred while waiting. */ |
| 380 | if (process_event ()) |
| 381 | { |
| 382 | return 1; |
| 383 | } |
| 384 | |
| 385 | /* If gdb_wait_for_event has returned 1, it means that one |
| 386 | event has been handled. We break out of the loop. */ |
| 387 | return 1; |
| 388 | } |
| 389 | |
| 390 | /* Start up the event loop. This is the entry point to the event loop |
| 391 | from the command loop. */ |
| 392 | |
| 393 | void |
| 394 | start_event_loop (void) |
| 395 | { |
| 396 | /* Loop until there is nothing to do. This is the entry point to the |
| 397 | event loop engine. gdb_do_one_event, called via catch_errors() |
| 398 | will process one event for each invocation. It blocks waits for |
| 399 | an event and then processes it. >0 when an event is processed, 0 |
| 400 | when catch_errors() caught an error and <0 when there are no |
| 401 | longer any event sources registered. */ |
| 402 | while (1) |
| 403 | { |
| 404 | int gdb_result; |
| 405 | |
| 406 | gdb_result = catch_errors (gdb_do_one_event, 0, "", RETURN_MASK_ALL); |
| 407 | if (gdb_result < 0) |
| 408 | break; |
| 409 | |
| 410 | /* If we long-jumped out of do_one_event, we probably |
| 411 | didn't get around to resetting the prompt, which leaves |
| 412 | readline in a messed-up state. Reset it here. */ |
| 413 | |
| 414 | if (gdb_result == 0) |
| 415 | { |
| 416 | /* FIXME: this should really be a call to a hook that is |
| 417 | interface specific, because interfaces can display the |
| 418 | prompt in their own way. */ |
| 419 | display_gdb_prompt (0); |
| 420 | /* This call looks bizarre, but it is required. If the user |
| 421 | entered a command that caused an error, |
| 422 | after_char_processing_hook won't be called from |
| 423 | rl_callback_read_char_wrapper. Using a cleanup there |
| 424 | won't work, since we want this function to be called |
| 425 | after a new prompt is printed. */ |
| 426 | if (after_char_processing_hook) |
| 427 | (*after_char_processing_hook) (); |
| 428 | /* Maybe better to set a flag to be checked somewhere as to |
| 429 | whether display the prompt or not. */ |
| 430 | } |
| 431 | } |
| 432 | |
| 433 | /* We are done with the event loop. There are no more event sources |
| 434 | to listen to. So we exit GDB. */ |
| 435 | return; |
| 436 | } |
| 437 | \f |
| 438 | |
| 439 | /* Wrapper function for create_file_handler, so that the caller |
| 440 | doesn't have to know implementation details about the use of poll |
| 441 | vs. select. */ |
| 442 | void |
| 443 | add_file_handler (int fd, handler_func * proc, gdb_client_data client_data) |
| 444 | { |
| 445 | #ifdef HAVE_POLL |
| 446 | struct pollfd fds; |
| 447 | #endif |
| 448 | |
| 449 | if (use_poll) |
| 450 | { |
| 451 | #ifdef HAVE_POLL |
| 452 | /* Check to see if poll () is usable. If not, we'll switch to |
| 453 | use select. This can happen on systems like |
| 454 | m68k-motorola-sys, `poll' cannot be used to wait for `stdin'. |
| 455 | On m68k-motorola-sysv, tty's are not stream-based and not |
| 456 | `poll'able. */ |
| 457 | fds.fd = fd; |
| 458 | fds.events = POLLIN; |
| 459 | if (poll (&fds, 1, 0) == 1 && (fds.revents & POLLNVAL)) |
| 460 | use_poll = 0; |
| 461 | #else |
| 462 | internal_error (__FILE__, __LINE__, |
| 463 | _("use_poll without HAVE_POLL")); |
| 464 | #endif /* HAVE_POLL */ |
| 465 | } |
| 466 | if (use_poll) |
| 467 | { |
| 468 | #ifdef HAVE_POLL |
| 469 | create_file_handler (fd, POLLIN, proc, client_data); |
| 470 | #else |
| 471 | internal_error (__FILE__, __LINE__, |
| 472 | _("use_poll without HAVE_POLL")); |
| 473 | #endif |
| 474 | } |
| 475 | else |
| 476 | create_file_handler (fd, GDB_READABLE | GDB_EXCEPTION, proc, client_data); |
| 477 | } |
| 478 | |
| 479 | /* Add a file handler/descriptor to the list of descriptors we are |
| 480 | interested in. |
| 481 | FD is the file descriptor for the file/stream to be listened to. |
| 482 | For the poll case, MASK is a combination (OR) of |
| 483 | POLLIN, POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM, |
| 484 | POLLWRBAND: these are the events we are interested in. If any of them |
| 485 | occurs, proc should be called. |
| 486 | For the select case, MASK is a combination of READABLE, WRITABLE, EXCEPTION. |
| 487 | PROC is the procedure that will be called when an event occurs for |
| 488 | FD. CLIENT_DATA is the argument to pass to PROC. */ |
| 489 | static void |
| 490 | create_file_handler (int fd, int mask, handler_func * proc, gdb_client_data client_data) |
| 491 | { |
| 492 | file_handler *file_ptr; |
| 493 | |
| 494 | /* Do we already have a file handler for this file? (We may be |
| 495 | changing its associated procedure). */ |
| 496 | for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; |
| 497 | file_ptr = file_ptr->next_file) |
| 498 | { |
| 499 | if (file_ptr->fd == fd) |
| 500 | break; |
| 501 | } |
| 502 | |
| 503 | /* It is a new file descriptor. Add it to the list. Otherwise, just |
| 504 | change the data associated with it. */ |
| 505 | if (file_ptr == NULL) |
| 506 | { |
| 507 | file_ptr = (file_handler *) xmalloc (sizeof (file_handler)); |
| 508 | file_ptr->fd = fd; |
| 509 | file_ptr->ready_mask = 0; |
| 510 | file_ptr->next_file = gdb_notifier.first_file_handler; |
| 511 | gdb_notifier.first_file_handler = file_ptr; |
| 512 | |
| 513 | if (use_poll) |
| 514 | { |
| 515 | #ifdef HAVE_POLL |
| 516 | gdb_notifier.num_fds++; |
| 517 | if (gdb_notifier.poll_fds) |
| 518 | gdb_notifier.poll_fds = |
| 519 | (struct pollfd *) xrealloc (gdb_notifier.poll_fds, |
| 520 | (gdb_notifier.num_fds |
| 521 | * sizeof (struct pollfd))); |
| 522 | else |
| 523 | gdb_notifier.poll_fds = |
| 524 | (struct pollfd *) xmalloc (sizeof (struct pollfd)); |
| 525 | (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->fd = fd; |
| 526 | (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->events = mask; |
| 527 | (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->revents = 0; |
| 528 | #else |
| 529 | internal_error (__FILE__, __LINE__, |
| 530 | _("use_poll without HAVE_POLL")); |
| 531 | #endif /* HAVE_POLL */ |
| 532 | } |
| 533 | else |
| 534 | { |
| 535 | if (mask & GDB_READABLE) |
| 536 | FD_SET (fd, &gdb_notifier.check_masks[0]); |
| 537 | else |
| 538 | FD_CLR (fd, &gdb_notifier.check_masks[0]); |
| 539 | |
| 540 | if (mask & GDB_WRITABLE) |
| 541 | FD_SET (fd, &gdb_notifier.check_masks[1]); |
| 542 | else |
| 543 | FD_CLR (fd, &gdb_notifier.check_masks[1]); |
| 544 | |
| 545 | if (mask & GDB_EXCEPTION) |
| 546 | FD_SET (fd, &gdb_notifier.check_masks[2]); |
| 547 | else |
| 548 | FD_CLR (fd, &gdb_notifier.check_masks[2]); |
| 549 | |
| 550 | if (gdb_notifier.num_fds <= fd) |
| 551 | gdb_notifier.num_fds = fd + 1; |
| 552 | } |
| 553 | } |
| 554 | |
| 555 | file_ptr->proc = proc; |
| 556 | file_ptr->client_data = client_data; |
| 557 | file_ptr->mask = mask; |
| 558 | } |
| 559 | |
| 560 | /* Remove the file descriptor FD from the list of monitored fd's: |
| 561 | i.e. we don't care anymore about events on the FD. */ |
| 562 | void |
| 563 | delete_file_handler (int fd) |
| 564 | { |
| 565 | file_handler *file_ptr, *prev_ptr = NULL; |
| 566 | int i; |
| 567 | #ifdef HAVE_POLL |
| 568 | int j; |
| 569 | struct pollfd *new_poll_fds; |
| 570 | #endif |
| 571 | |
| 572 | /* Find the entry for the given file. */ |
| 573 | |
| 574 | for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; |
| 575 | file_ptr = file_ptr->next_file) |
| 576 | { |
| 577 | if (file_ptr->fd == fd) |
| 578 | break; |
| 579 | } |
| 580 | |
| 581 | if (file_ptr == NULL) |
| 582 | return; |
| 583 | |
| 584 | if (use_poll) |
| 585 | { |
| 586 | #ifdef HAVE_POLL |
| 587 | /* Create a new poll_fds array by copying every fd's information but the |
| 588 | one we want to get rid of. */ |
| 589 | |
| 590 | new_poll_fds = |
| 591 | (struct pollfd *) xmalloc ((gdb_notifier.num_fds - 1) * sizeof (struct pollfd)); |
| 592 | |
| 593 | for (i = 0, j = 0; i < gdb_notifier.num_fds; i++) |
| 594 | { |
| 595 | if ((gdb_notifier.poll_fds + i)->fd != fd) |
| 596 | { |
| 597 | (new_poll_fds + j)->fd = (gdb_notifier.poll_fds + i)->fd; |
| 598 | (new_poll_fds + j)->events = (gdb_notifier.poll_fds + i)->events; |
| 599 | (new_poll_fds + j)->revents = (gdb_notifier.poll_fds + i)->revents; |
| 600 | j++; |
| 601 | } |
| 602 | } |
| 603 | xfree (gdb_notifier.poll_fds); |
| 604 | gdb_notifier.poll_fds = new_poll_fds; |
| 605 | gdb_notifier.num_fds--; |
| 606 | #else |
| 607 | internal_error (__FILE__, __LINE__, |
| 608 | _("use_poll without HAVE_POLL")); |
| 609 | #endif /* HAVE_POLL */ |
| 610 | } |
| 611 | else |
| 612 | { |
| 613 | if (file_ptr->mask & GDB_READABLE) |
| 614 | FD_CLR (fd, &gdb_notifier.check_masks[0]); |
| 615 | if (file_ptr->mask & GDB_WRITABLE) |
| 616 | FD_CLR (fd, &gdb_notifier.check_masks[1]); |
| 617 | if (file_ptr->mask & GDB_EXCEPTION) |
| 618 | FD_CLR (fd, &gdb_notifier.check_masks[2]); |
| 619 | |
| 620 | /* Find current max fd. */ |
| 621 | |
| 622 | if ((fd + 1) == gdb_notifier.num_fds) |
| 623 | { |
| 624 | gdb_notifier.num_fds--; |
| 625 | for (i = gdb_notifier.num_fds; i; i--) |
| 626 | { |
| 627 | if (FD_ISSET (i - 1, &gdb_notifier.check_masks[0]) |
| 628 | || FD_ISSET (i - 1, &gdb_notifier.check_masks[1]) |
| 629 | || FD_ISSET (i - 1, &gdb_notifier.check_masks[2])) |
| 630 | break; |
| 631 | } |
| 632 | gdb_notifier.num_fds = i; |
| 633 | } |
| 634 | } |
| 635 | |
| 636 | /* Deactivate the file descriptor, by clearing its mask, |
| 637 | so that it will not fire again. */ |
| 638 | |
| 639 | file_ptr->mask = 0; |
| 640 | |
| 641 | /* Get rid of the file handler in the file handler list. */ |
| 642 | if (file_ptr == gdb_notifier.first_file_handler) |
| 643 | gdb_notifier.first_file_handler = file_ptr->next_file; |
| 644 | else |
| 645 | { |
| 646 | for (prev_ptr = gdb_notifier.first_file_handler; |
| 647 | prev_ptr->next_file != file_ptr; |
| 648 | prev_ptr = prev_ptr->next_file) |
| 649 | ; |
| 650 | prev_ptr->next_file = file_ptr->next_file; |
| 651 | } |
| 652 | xfree (file_ptr); |
| 653 | } |
| 654 | |
| 655 | /* Handle the given event by calling the procedure associated to the |
| 656 | corresponding file handler. Called by process_event indirectly, |
| 657 | through event_ptr->proc. EVENT_FILE_DESC is file descriptor of the |
| 658 | event in the front of the event queue. */ |
| 659 | static void |
| 660 | handle_file_event (int event_file_desc) |
| 661 | { |
| 662 | file_handler *file_ptr; |
| 663 | int mask; |
| 664 | #ifdef HAVE_POLL |
| 665 | int error_mask; |
| 666 | int error_mask_returned; |
| 667 | #endif |
| 668 | |
| 669 | /* Search the file handler list to find one that matches the fd in |
| 670 | the event. */ |
| 671 | for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; |
| 672 | file_ptr = file_ptr->next_file) |
| 673 | { |
| 674 | if (file_ptr->fd == event_file_desc) |
| 675 | { |
| 676 | /* With poll, the ready_mask could have any of three events |
| 677 | set to 1: POLLHUP, POLLERR, POLLNVAL. These events cannot |
| 678 | be used in the requested event mask (events), but they |
| 679 | can be returned in the return mask (revents). We need to |
| 680 | check for those event too, and add them to the mask which |
| 681 | will be passed to the handler. */ |
| 682 | |
| 683 | /* See if the desired events (mask) match the received |
| 684 | events (ready_mask). */ |
| 685 | |
| 686 | if (use_poll) |
| 687 | { |
| 688 | #ifdef HAVE_POLL |
| 689 | error_mask = POLLHUP | POLLERR | POLLNVAL; |
| 690 | mask = (file_ptr->ready_mask & file_ptr->mask) | |
| 691 | (file_ptr->ready_mask & error_mask); |
| 692 | error_mask_returned = mask & error_mask; |
| 693 | |
| 694 | if (error_mask_returned != 0) |
| 695 | { |
| 696 | /* Work in progress. We may need to tell somebody what |
| 697 | kind of error we had. */ |
| 698 | if (error_mask_returned & POLLHUP) |
| 699 | printf_unfiltered (_("Hangup detected on fd %d\n"), file_ptr->fd); |
| 700 | if (error_mask_returned & POLLERR) |
| 701 | printf_unfiltered (_("Error detected on fd %d\n"), file_ptr->fd); |
| 702 | if (error_mask_returned & POLLNVAL) |
| 703 | printf_unfiltered (_("Invalid or non-`poll'able fd %d\n"), file_ptr->fd); |
| 704 | file_ptr->error = 1; |
| 705 | } |
| 706 | else |
| 707 | file_ptr->error = 0; |
| 708 | #else |
| 709 | internal_error (__FILE__, __LINE__, |
| 710 | _("use_poll without HAVE_POLL")); |
| 711 | #endif /* HAVE_POLL */ |
| 712 | } |
| 713 | else |
| 714 | { |
| 715 | if (file_ptr->ready_mask & GDB_EXCEPTION) |
| 716 | { |
| 717 | printf_unfiltered (_("Exception condition detected on fd %d\n"), file_ptr->fd); |
| 718 | file_ptr->error = 1; |
| 719 | } |
| 720 | else |
| 721 | file_ptr->error = 0; |
| 722 | mask = file_ptr->ready_mask & file_ptr->mask; |
| 723 | } |
| 724 | |
| 725 | /* Clear the received events for next time around. */ |
| 726 | file_ptr->ready_mask = 0; |
| 727 | |
| 728 | /* If there was a match, then call the handler. */ |
| 729 | if (mask != 0) |
| 730 | (*file_ptr->proc) (file_ptr->error, file_ptr->client_data); |
| 731 | break; |
| 732 | } |
| 733 | } |
| 734 | } |
| 735 | |
| 736 | /* Called by gdb_do_one_event to wait for new events on the |
| 737 | monitored file descriptors. Queue file events as they are |
| 738 | detected by the poll. |
| 739 | If there are no events, this function will block in the |
| 740 | call to poll. |
| 741 | Return -1 if there are no files descriptors to monitor, |
| 742 | otherwise return 0. */ |
| 743 | static int |
| 744 | gdb_wait_for_event (void) |
| 745 | { |
| 746 | file_handler *file_ptr; |
| 747 | gdb_event *file_event_ptr; |
| 748 | int num_found = 0; |
| 749 | int i; |
| 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 (use_poll) |
| 759 | { |
| 760 | #ifdef HAVE_POLL |
| 761 | num_found = |
| 762 | poll (gdb_notifier.poll_fds, |
| 763 | (unsigned long) gdb_notifier.num_fds, |
| 764 | gdb_notifier.timeout_valid ? gdb_notifier.poll_timeout : -1); |
| 765 | |
| 766 | /* Don't print anything if we get out of poll because of a |
| 767 | signal. */ |
| 768 | if (num_found == -1 && errno != EINTR) |
| 769 | perror_with_name (("poll")); |
| 770 | #else |
| 771 | internal_error (__FILE__, __LINE__, |
| 772 | _("use_poll without HAVE_POLL")); |
| 773 | #endif /* HAVE_POLL */ |
| 774 | } |
| 775 | else |
| 776 | { |
| 777 | gdb_notifier.ready_masks[0] = gdb_notifier.check_masks[0]; |
| 778 | gdb_notifier.ready_masks[1] = gdb_notifier.check_masks[1]; |
| 779 | gdb_notifier.ready_masks[2] = gdb_notifier.check_masks[2]; |
| 780 | num_found = gdb_select (gdb_notifier.num_fds, |
| 781 | &gdb_notifier.ready_masks[0], |
| 782 | &gdb_notifier.ready_masks[1], |
| 783 | &gdb_notifier.ready_masks[2], |
| 784 | gdb_notifier.timeout_valid |
| 785 | ? &gdb_notifier.select_timeout : NULL); |
| 786 | |
| 787 | /* Clear the masks after an error from select. */ |
| 788 | if (num_found == -1) |
| 789 | { |
| 790 | FD_ZERO (&gdb_notifier.ready_masks[0]); |
| 791 | FD_ZERO (&gdb_notifier.ready_masks[1]); |
| 792 | FD_ZERO (&gdb_notifier.ready_masks[2]); |
| 793 | /* Dont print anything is we got a signal, let gdb handle it. */ |
| 794 | if (errno != EINTR) |
| 795 | perror_with_name (("select")); |
| 796 | } |
| 797 | } |
| 798 | |
| 799 | /* Enqueue all detected file events. */ |
| 800 | |
| 801 | if (use_poll) |
| 802 | { |
| 803 | #ifdef HAVE_POLL |
| 804 | for (i = 0; (i < gdb_notifier.num_fds) && (num_found > 0); i++) |
| 805 | { |
| 806 | if ((gdb_notifier.poll_fds + i)->revents) |
| 807 | num_found--; |
| 808 | else |
| 809 | continue; |
| 810 | |
| 811 | for (file_ptr = gdb_notifier.first_file_handler; |
| 812 | file_ptr != NULL; |
| 813 | file_ptr = file_ptr->next_file) |
| 814 | { |
| 815 | if (file_ptr->fd == (gdb_notifier.poll_fds + i)->fd) |
| 816 | break; |
| 817 | } |
| 818 | |
| 819 | if (file_ptr) |
| 820 | { |
| 821 | /* Enqueue an event only if this is still a new event for |
| 822 | this fd. */ |
| 823 | if (file_ptr->ready_mask == 0) |
| 824 | { |
| 825 | file_event_ptr = create_file_event (file_ptr->fd); |
| 826 | async_queue_event (file_event_ptr, TAIL); |
| 827 | } |
| 828 | } |
| 829 | |
| 830 | file_ptr->ready_mask = (gdb_notifier.poll_fds + i)->revents; |
| 831 | } |
| 832 | #else |
| 833 | internal_error (__FILE__, __LINE__, |
| 834 | _("use_poll without HAVE_POLL")); |
| 835 | #endif /* HAVE_POLL */ |
| 836 | } |
| 837 | else |
| 838 | { |
| 839 | for (file_ptr = gdb_notifier.first_file_handler; |
| 840 | (file_ptr != NULL) && (num_found > 0); |
| 841 | file_ptr = file_ptr->next_file) |
| 842 | { |
| 843 | int mask = 0; |
| 844 | |
| 845 | if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[0])) |
| 846 | mask |= GDB_READABLE; |
| 847 | if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[1])) |
| 848 | mask |= GDB_WRITABLE; |
| 849 | if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[2])) |
| 850 | mask |= GDB_EXCEPTION; |
| 851 | |
| 852 | if (!mask) |
| 853 | continue; |
| 854 | else |
| 855 | num_found--; |
| 856 | |
| 857 | /* Enqueue an event only if this is still a new event for |
| 858 | this fd. */ |
| 859 | |
| 860 | if (file_ptr->ready_mask == 0) |
| 861 | { |
| 862 | file_event_ptr = create_file_event (file_ptr->fd); |
| 863 | async_queue_event (file_event_ptr, TAIL); |
| 864 | } |
| 865 | file_ptr->ready_mask = mask; |
| 866 | } |
| 867 | } |
| 868 | return 0; |
| 869 | } |
| 870 | \f |
| 871 | |
| 872 | /* Create an asynchronous handler, allocating memory for it. |
| 873 | Return a pointer to the newly created handler. |
| 874 | This pointer will be used to invoke the handler by |
| 875 | invoke_async_signal_handler. |
| 876 | PROC is the function to call with CLIENT_DATA argument |
| 877 | whenever the handler is invoked. */ |
| 878 | async_signal_handler * |
| 879 | create_async_signal_handler (sig_handler_func * proc, gdb_client_data client_data) |
| 880 | { |
| 881 | async_signal_handler *async_handler_ptr; |
| 882 | |
| 883 | async_handler_ptr = |
| 884 | (async_signal_handler *) xmalloc (sizeof (async_signal_handler)); |
| 885 | async_handler_ptr->ready = 0; |
| 886 | async_handler_ptr->next_handler = NULL; |
| 887 | async_handler_ptr->proc = proc; |
| 888 | async_handler_ptr->client_data = client_data; |
| 889 | if (sighandler_list.first_handler == NULL) |
| 890 | sighandler_list.first_handler = async_handler_ptr; |
| 891 | else |
| 892 | sighandler_list.last_handler->next_handler = async_handler_ptr; |
| 893 | sighandler_list.last_handler = async_handler_ptr; |
| 894 | return async_handler_ptr; |
| 895 | } |
| 896 | |
| 897 | /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information will |
| 898 | be used when the handlers are invoked, after we have waited for |
| 899 | some event. The caller of this function is the interrupt handler |
| 900 | associated with a signal. */ |
| 901 | void |
| 902 | mark_async_signal_handler (async_signal_handler * async_handler_ptr) |
| 903 | { |
| 904 | ((async_signal_handler *) async_handler_ptr)->ready = 1; |
| 905 | async_handler_ready = 1; |
| 906 | } |
| 907 | |
| 908 | /* Call all the handlers that are ready. */ |
| 909 | static void |
| 910 | invoke_async_signal_handler (void) |
| 911 | { |
| 912 | async_signal_handler *async_handler_ptr; |
| 913 | |
| 914 | if (async_handler_ready == 0) |
| 915 | return; |
| 916 | async_handler_ready = 0; |
| 917 | |
| 918 | /* Invoke ready handlers. */ |
| 919 | |
| 920 | while (1) |
| 921 | { |
| 922 | for (async_handler_ptr = sighandler_list.first_handler; |
| 923 | async_handler_ptr != NULL; |
| 924 | async_handler_ptr = async_handler_ptr->next_handler) |
| 925 | { |
| 926 | if (async_handler_ptr->ready) |
| 927 | break; |
| 928 | } |
| 929 | if (async_handler_ptr == NULL) |
| 930 | break; |
| 931 | async_handler_ptr->ready = 0; |
| 932 | (*async_handler_ptr->proc) (async_handler_ptr->client_data); |
| 933 | } |
| 934 | |
| 935 | return; |
| 936 | } |
| 937 | |
| 938 | /* Delete an asynchronous handler (ASYNC_HANDLER_PTR). |
| 939 | Free the space allocated for it. */ |
| 940 | void |
| 941 | delete_async_signal_handler (async_signal_handler ** async_handler_ptr) |
| 942 | { |
| 943 | async_signal_handler *prev_ptr; |
| 944 | |
| 945 | if (sighandler_list.first_handler == (*async_handler_ptr)) |
| 946 | { |
| 947 | sighandler_list.first_handler = (*async_handler_ptr)->next_handler; |
| 948 | if (sighandler_list.first_handler == NULL) |
| 949 | sighandler_list.last_handler = NULL; |
| 950 | } |
| 951 | else |
| 952 | { |
| 953 | prev_ptr = sighandler_list.first_handler; |
| 954 | while (prev_ptr->next_handler != (*async_handler_ptr) && prev_ptr) |
| 955 | prev_ptr = prev_ptr->next_handler; |
| 956 | prev_ptr->next_handler = (*async_handler_ptr)->next_handler; |
| 957 | if (sighandler_list.last_handler == (*async_handler_ptr)) |
| 958 | sighandler_list.last_handler = prev_ptr; |
| 959 | } |
| 960 | xfree ((*async_handler_ptr)); |
| 961 | (*async_handler_ptr) = NULL; |
| 962 | } |
| 963 | |
| 964 | /* Is it necessary to call invoke_async_signal_handler? */ |
| 965 | static int |
| 966 | check_async_ready (void) |
| 967 | { |
| 968 | return async_handler_ready; |
| 969 | } |
| 970 | |
| 971 | /* Create a timer that will expire in MILLISECONDS from now. When the |
| 972 | timer is ready, PROC will be executed. At creation, the timer is |
| 973 | aded to the timers queue. This queue is kept sorted in order of |
| 974 | increasing timers. Return a handle to the timer struct. */ |
| 975 | int |
| 976 | create_timer (int milliseconds, timer_handler_func * proc, gdb_client_data client_data) |
| 977 | { |
| 978 | struct gdb_timer *timer_ptr, *timer_index, *prev_timer; |
| 979 | struct timeval time_now, delta; |
| 980 | |
| 981 | /* compute seconds */ |
| 982 | delta.tv_sec = milliseconds / 1000; |
| 983 | /* compute microseconds */ |
| 984 | delta.tv_usec = (milliseconds % 1000) * 1000; |
| 985 | |
| 986 | gettimeofday (&time_now, NULL); |
| 987 | |
| 988 | timer_ptr = (struct gdb_timer *) xmalloc (sizeof (gdb_timer)); |
| 989 | timer_ptr->when.tv_sec = time_now.tv_sec + delta.tv_sec; |
| 990 | timer_ptr->when.tv_usec = time_now.tv_usec + delta.tv_usec; |
| 991 | /* carry? */ |
| 992 | if (timer_ptr->when.tv_usec >= 1000000) |
| 993 | { |
| 994 | timer_ptr->when.tv_sec += 1; |
| 995 | timer_ptr->when.tv_usec -= 1000000; |
| 996 | } |
| 997 | timer_ptr->proc = proc; |
| 998 | timer_ptr->client_data = client_data; |
| 999 | timer_list.num_timers++; |
| 1000 | timer_ptr->timer_id = timer_list.num_timers; |
| 1001 | |
| 1002 | /* Now add the timer to the timer queue, making sure it is sorted in |
| 1003 | increasing order of expiration. */ |
| 1004 | |
| 1005 | for (timer_index = timer_list.first_timer; |
| 1006 | timer_index != NULL; |
| 1007 | timer_index = timer_index->next) |
| 1008 | { |
| 1009 | /* If the seconds field is greater or if it is the same, but the |
| 1010 | microsecond field is greater. */ |
| 1011 | if ((timer_index->when.tv_sec > timer_ptr->when.tv_sec) || |
| 1012 | ((timer_index->when.tv_sec == timer_ptr->when.tv_sec) |
| 1013 | && (timer_index->when.tv_usec > timer_ptr->when.tv_usec))) |
| 1014 | break; |
| 1015 | } |
| 1016 | |
| 1017 | if (timer_index == timer_list.first_timer) |
| 1018 | { |
| 1019 | timer_ptr->next = timer_list.first_timer; |
| 1020 | timer_list.first_timer = timer_ptr; |
| 1021 | |
| 1022 | } |
| 1023 | else |
| 1024 | { |
| 1025 | for (prev_timer = timer_list.first_timer; |
| 1026 | prev_timer->next != timer_index; |
| 1027 | prev_timer = prev_timer->next) |
| 1028 | ; |
| 1029 | |
| 1030 | prev_timer->next = timer_ptr; |
| 1031 | timer_ptr->next = timer_index; |
| 1032 | } |
| 1033 | |
| 1034 | gdb_notifier.timeout_valid = 0; |
| 1035 | return timer_ptr->timer_id; |
| 1036 | } |
| 1037 | |
| 1038 | /* There is a chance that the creator of the timer wants to get rid of |
| 1039 | it before it expires. */ |
| 1040 | void |
| 1041 | delete_timer (int id) |
| 1042 | { |
| 1043 | struct gdb_timer *timer_ptr, *prev_timer = NULL; |
| 1044 | |
| 1045 | /* Find the entry for the given timer. */ |
| 1046 | |
| 1047 | for (timer_ptr = timer_list.first_timer; timer_ptr != NULL; |
| 1048 | timer_ptr = timer_ptr->next) |
| 1049 | { |
| 1050 | if (timer_ptr->timer_id == id) |
| 1051 | break; |
| 1052 | } |
| 1053 | |
| 1054 | if (timer_ptr == NULL) |
| 1055 | return; |
| 1056 | /* Get rid of the timer in the timer list. */ |
| 1057 | if (timer_ptr == timer_list.first_timer) |
| 1058 | timer_list.first_timer = timer_ptr->next; |
| 1059 | else |
| 1060 | { |
| 1061 | for (prev_timer = timer_list.first_timer; |
| 1062 | prev_timer->next != timer_ptr; |
| 1063 | prev_timer = prev_timer->next) |
| 1064 | ; |
| 1065 | prev_timer->next = timer_ptr->next; |
| 1066 | } |
| 1067 | xfree (timer_ptr); |
| 1068 | |
| 1069 | gdb_notifier.timeout_valid = 0; |
| 1070 | } |
| 1071 | |
| 1072 | /* When a timer event is put on the event queue, it will be handled by |
| 1073 | this function. Just call the assiciated procedure and delete the |
| 1074 | timer event from the event queue. Repeat this for each timer that |
| 1075 | has expired. */ |
| 1076 | static void |
| 1077 | handle_timer_event (int dummy) |
| 1078 | { |
| 1079 | struct timeval time_now; |
| 1080 | struct gdb_timer *timer_ptr, *saved_timer; |
| 1081 | |
| 1082 | gettimeofday (&time_now, NULL); |
| 1083 | timer_ptr = timer_list.first_timer; |
| 1084 | |
| 1085 | while (timer_ptr != NULL) |
| 1086 | { |
| 1087 | if ((timer_ptr->when.tv_sec > time_now.tv_sec) || |
| 1088 | ((timer_ptr->when.tv_sec == time_now.tv_sec) && |
| 1089 | (timer_ptr->when.tv_usec > time_now.tv_usec))) |
| 1090 | break; |
| 1091 | |
| 1092 | /* Get rid of the timer from the beginning of the list. */ |
| 1093 | timer_list.first_timer = timer_ptr->next; |
| 1094 | saved_timer = timer_ptr; |
| 1095 | timer_ptr = timer_ptr->next; |
| 1096 | /* Call the procedure associated with that timer. */ |
| 1097 | (*saved_timer->proc) (saved_timer->client_data); |
| 1098 | xfree (saved_timer); |
| 1099 | } |
| 1100 | |
| 1101 | gdb_notifier.timeout_valid = 0; |
| 1102 | } |
| 1103 | |
| 1104 | /* Check whether any timers in the timers queue are ready. If at least |
| 1105 | one timer is ready, stick an event onto the event queue. Even in |
| 1106 | case more than one timer is ready, one event is enough, because the |
| 1107 | handle_timer_event() will go through the timers list and call the |
| 1108 | procedures associated with all that have expired. Update the |
| 1109 | timeout for the select() or poll() as well. */ |
| 1110 | static void |
| 1111 | poll_timers (void) |
| 1112 | { |
| 1113 | struct timeval time_now, delta; |
| 1114 | gdb_event *event_ptr; |
| 1115 | |
| 1116 | if (timer_list.first_timer != NULL) |
| 1117 | { |
| 1118 | gettimeofday (&time_now, NULL); |
| 1119 | delta.tv_sec = timer_list.first_timer->when.tv_sec - time_now.tv_sec; |
| 1120 | delta.tv_usec = timer_list.first_timer->when.tv_usec - time_now.tv_usec; |
| 1121 | /* borrow? */ |
| 1122 | if (delta.tv_usec < 0) |
| 1123 | { |
| 1124 | delta.tv_sec -= 1; |
| 1125 | delta.tv_usec += 1000000; |
| 1126 | } |
| 1127 | |
| 1128 | /* Oops it expired already. Tell select / poll to return |
| 1129 | immediately. (Cannot simply test if delta.tv_sec is negative |
| 1130 | because time_t might be unsigned.) */ |
| 1131 | if (timer_list.first_timer->when.tv_sec < time_now.tv_sec |
| 1132 | || (timer_list.first_timer->when.tv_sec == time_now.tv_sec |
| 1133 | && timer_list.first_timer->when.tv_usec < time_now.tv_usec)) |
| 1134 | { |
| 1135 | delta.tv_sec = 0; |
| 1136 | delta.tv_usec = 0; |
| 1137 | } |
| 1138 | |
| 1139 | if (delta.tv_sec == 0 && delta.tv_usec == 0) |
| 1140 | { |
| 1141 | event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event)); |
| 1142 | event_ptr->proc = handle_timer_event; |
| 1143 | event_ptr->fd = timer_list.first_timer->timer_id; |
| 1144 | async_queue_event (event_ptr, TAIL); |
| 1145 | } |
| 1146 | |
| 1147 | /* Now we need to update the timeout for select/ poll, because we |
| 1148 | don't want to sit there while this timer is expiring. */ |
| 1149 | if (use_poll) |
| 1150 | { |
| 1151 | #ifdef HAVE_POLL |
| 1152 | gdb_notifier.poll_timeout = delta.tv_sec * 1000; |
| 1153 | #else |
| 1154 | internal_error (__FILE__, __LINE__, |
| 1155 | _("use_poll without HAVE_POLL")); |
| 1156 | #endif /* HAVE_POLL */ |
| 1157 | } |
| 1158 | else |
| 1159 | { |
| 1160 | gdb_notifier.select_timeout.tv_sec = delta.tv_sec; |
| 1161 | gdb_notifier.select_timeout.tv_usec = delta.tv_usec; |
| 1162 | } |
| 1163 | gdb_notifier.timeout_valid = 1; |
| 1164 | } |
| 1165 | else |
| 1166 | gdb_notifier.timeout_valid = 0; |
| 1167 | } |