diff options
| -rw-r--r-- | gdb/ChangeLog | 26 | ||||
| -rw-r--r-- | gdb/event-loop.c | 334 | ||||
| -rw-r--r-- | gdb/event-loop.h | 1 | ||||
| -rw-r--r-- | gdb/top.c | 1 |
4 files changed, 119 insertions, 243 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 9a36dc8276b..44dc1eab376 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,31 @@ 2015-02-03 Pedro Alves <palves@redhat.com> + * event-loop.c: Don't declare nor define a queue type for + gdb_event_p. + (event_queue): Delete. + (create_event, create_file_event, gdb_event_xfree) + (initialize_event_loop, process_event): Delete. + (gdb_do_one_event): Return as soon as one event is handled. + (handle_file_event): Change prototype. Used the passed in + file_handler pointer and ready_mask instead of looping over all + file handlers. + (gdb_wait_for_event): Update the poll/select timeouts before + blocking. Run event handlers directly instead of queueing events. + Return as soon as one event is handled. + (struct async_event_handler_data): Delete. + (invoke_async_event_handler): Delete. + (check_async_event_handlers): Change return type to int. Run + event handlers directly instead of queueing events. Return as + soon as one event is handled. + (handle_timer_event): Delete. + (update_wait_timeout): New function, factored out from + poll_timers. + (poll_timers): Reimplement. + * event-loop.h (initialize_event_loop): Delete declaration. + * top.c (gdb_init): Don't call initialize_event_loop. + +2015-02-03 Pedro Alves <palves@redhat.com> + * event-loop.c (clear_async_event_handler): New function. * event-loop.h (clear_async_event_handler): New declaration. * record-btrace.c (record_btrace_async): New function. diff --git a/gdb/event-loop.c b/gdb/event-loop.c index e4de57265df..7425b3acaa0 100644 --- a/gdb/event-loop.c +++ b/gdb/event-loop.c @@ -135,10 +135,6 @@ typedef struct async_event_handler } async_event_handler; -DECLARE_QUEUE_P(gdb_event_p); -DEFINE_QUEUE_P(gdb_event_p); -static QUEUE(gdb_event_p) *event_queue = NULL; - /* Gdb_notifier is just a list of file descriptors gdb is interested in. These are the input file descriptor, and the target file descriptor. We have two flavors of the notifier, one for platforms @@ -246,104 +242,12 @@ async_event_handler_list; static int invoke_async_signal_handlers (void); static void create_file_handler (int fd, int mask, handler_func *proc, gdb_client_data client_data); -static void handle_file_event (event_data data); -static void check_async_event_handlers (void); +static int check_async_event_handlers (void); static int gdb_wait_for_event (int); -static void poll_timers (void); +static int update_wait_timeout (void); +static int poll_timers (void); -/* Create a generic event, to be enqueued in the event queue for - processing. PROC is the procedure associated to the event. DATA - is passed to PROC upon PROC invocation. */ - -static gdb_event * -create_event (event_handler_func proc, event_data data) -{ - gdb_event *event; - - event = xmalloc (sizeof (*event)); - event->proc = proc; - event->data = data; - - return event; -} - -/* Create a file event, to be enqueued in the event queue for - processing. The procedure associated to this event is always - handle_file_event, which will in turn invoke the one that was - associated to FD when it was registered with the event loop. */ -static gdb_event * -create_file_event (int fd) -{ - event_data data; - - data.integer = fd; - return create_event (handle_file_event, data); -} - - -/* Free EVENT. */ - -static void -gdb_event_xfree (struct gdb_event *event) -{ - xfree (event); -} - -/* Initialize the event queue. */ - -void -initialize_event_loop (void) -{ - event_queue = QUEUE_alloc (gdb_event_p, gdb_event_xfree); -} - -/* Process one event. - The event can be the next one to be serviced in the event queue, - or an asynchronous event handler can be invoked in response to - the reception of a signal. - If an event was processed (either way), 1 is returned otherwise - 0 is returned. - Scan the queue from head to tail, processing therefore the high - priority events first, by invoking the associated event handler - procedure. */ -static int -process_event (void) -{ - /* First let's see if there are any asynchronous event handlers that - are ready. These would be the result of invoking any of the - signal handlers. */ - - if (invoke_async_signal_handlers ()) - return 1; - - /* Look in the event queue to find an event that is ready - to be processed. */ - - if (!QUEUE_is_empty (gdb_event_p, event_queue)) - { - /* Let's get rid of the event from the event queue. We need to - do this now because while processing the event, the proc - function could end up calling 'error' and therefore jump out - to the caller of this function, gdb_do_one_event. In that - case, we would have on the event queue an event wich has been - processed, but not deleted. */ - gdb_event *event_ptr = QUEUE_deque (gdb_event_p, event_queue); - /* Call the handler for the event. */ - event_handler_func *proc = event_ptr->proc; - event_data data = event_ptr->data; - - gdb_event_xfree (event_ptr); - - /* Now call the procedure associated with the event. */ - (*proc) (data); - return 1; - } - - /* This is the case if there are no event on the event queue. */ - return 0; -} - /* Process one high level event. If nothing is ready at this time, wait for something to happen (via gdb_wait_for_event), then process it. Returns >0 if something was done otherwise returns <0 (this @@ -356,40 +260,42 @@ gdb_do_one_event (void) const int number_of_sources = 3; int current = 0; - /* Any events already waiting in the queue? */ - if (process_event ()) + /* First let's see if there are any asynchronous signal handlers + that are ready. These would be the result of invoking any of the + signal handlers. */ + if (invoke_async_signal_handlers ()) return 1; /* To level the fairness across event sources, we poll them in a round-robin fashion. */ for (current = 0; current < number_of_sources; current++) { + int res; + switch (event_source_head) { case 0: - /* Are any timers that are ready? If so, put an event on the - queue. */ - poll_timers (); + /* Are any timers that are ready? */ + res = poll_timers (); break; case 1: /* Are there events already waiting to be collected on the monitored file descriptors? */ - gdb_wait_for_event (0); + res = gdb_wait_for_event (0); break; case 2: /* Are there any asynchronous event handlers ready? */ - check_async_event_handlers (); + res = check_async_event_handlers (); break; } event_source_head++; if (event_source_head == number_of_sources) event_source_head = 0; - } - /* Handle any new events collected. */ - if (process_event ()) - return 1; + if (res > 0) + return 1; + } /* Block waiting for a new event. If gdb_wait_for_event returns -1, we should get out because this means that there are no event @@ -399,10 +305,6 @@ gdb_do_one_event (void) if (gdb_wait_for_event (1) < 0) return -1; - /* Handle any new events occurred while waiting. */ - if (process_event ()) - return 1; - /* If gdb_wait_for_event has returned 1, it means that one event has been handled. We break out of the loop. */ return 1; @@ -684,25 +586,17 @@ delete_file_handler (int fd) } /* Handle the given event by calling the procedure associated to the - corresponding file handler. Called by process_event indirectly, - through event_ptr->proc. EVENT_FILE_DESC is file descriptor of the - event in the front of the event queue. */ + corresponding file handler. */ + static void -handle_file_event (event_data data) +handle_file_event (file_handler *file_ptr, int ready_mask) { - file_handler *file_ptr; int mask; #ifdef HAVE_POLL int error_mask; #endif - int event_file_desc = data.integer; - /* Search the file handler list to find one that matches the fd in - the event. */ - for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; - file_ptr = file_ptr->next_file) { - if (file_ptr->fd == event_file_desc) { /* With poll, the ready_mask could have any of three events set to 1: POLLHUP, POLLERR, POLLNVAL. These events @@ -720,7 +614,7 @@ handle_file_event (event_data data) /* POLLHUP means EOF, but can be combined with POLLIN to signal more data to read. */ error_mask = POLLHUP | POLLERR | POLLNVAL; - mask = file_ptr->ready_mask & (file_ptr->mask | error_mask); + mask = ready_mask & (file_ptr->mask | error_mask); if ((mask & (POLLERR | POLLNVAL)) != 0) { @@ -743,7 +637,7 @@ handle_file_event (event_data data) } else { - if (file_ptr->ready_mask & GDB_EXCEPTION) + if (ready_mask & GDB_EXCEPTION) { printf_unfiltered (_("Exception condition detected " "on fd %d\n"), file_ptr->fd); @@ -751,30 +645,27 @@ handle_file_event (event_data data) } else file_ptr->error = 0; - mask = file_ptr->ready_mask & file_ptr->mask; + mask = ready_mask & file_ptr->mask; } - /* Clear the received events for next time around. */ - file_ptr->ready_mask = 0; - /* If there was a match, then call the handler. */ if (mask != 0) (*file_ptr->proc) (file_ptr->error, file_ptr->client_data); - break; } } } -/* Called by gdb_do_one_event to wait for new events on the monitored - file descriptors. Queue file events as they are detected by the - poll. If BLOCK and if there are no events, this function will - block in the call to poll. Return -1 if there are no file - descriptors to monitor, otherwise return 0. */ +/* Wait for new events on the monitored file descriptors. Run the + event handler if the first descriptor that is detected by the poll. + If BLOCK and if there are no events, this function will block in + the call to poll. Return 1 if an event was handled. Return -1 if + there are no file descriptors to monitor. Return 1 if an event was + handled, otherwise returns 0. */ + static int gdb_wait_for_event (int block) { file_handler *file_ptr; - gdb_event *file_event_ptr; int num_found = 0; int i; @@ -785,6 +676,9 @@ gdb_wait_for_event (int block) if (gdb_notifier.num_fds == 0) return -1; + if (block) + update_wait_timeout (); + if (use_poll) { #ifdef HAVE_POLL @@ -844,7 +738,10 @@ gdb_wait_for_event (int block) } } - /* Enqueue all detected file events. */ + /* Run event handlers. We always run just one handler and go back + to polling, in case a handler changes the notifier list. Since + events for sources we haven't consumed yet wake poll/select + immediately, no event is lost. */ if (use_poll) { @@ -866,14 +763,10 @@ gdb_wait_for_event (int block) if (file_ptr) { - /* Enqueue an event only if this is still a new event for - this fd. */ - if (file_ptr->ready_mask == 0) - { - file_event_ptr = create_file_event (file_ptr->fd); - QUEUE_enque (gdb_event_p, event_queue, file_event_ptr); - } - file_ptr->ready_mask = (gdb_notifier.poll_fds + i)->revents; + int mask = (gdb_notifier.poll_fds + i)->revents; + + handle_file_event (file_ptr, mask); + return 1; } } #else @@ -901,15 +794,8 @@ gdb_wait_for_event (int block) else num_found--; - /* Enqueue an event only if this is still a new event for - this fd. */ - - if (file_ptr->ready_mask == 0) - { - file_event_ptr = create_file_event (file_ptr->fd); - QUEUE_enque (gdb_event_p, event_queue, file_event_ptr); - } - file_ptr->ready_mask = mask; + handle_file_event (file_ptr, mask); + return 1; } } return 0; @@ -1058,32 +944,13 @@ clear_async_event_handler (async_event_handler *async_handler_ptr) async_handler_ptr->ready = 0; } -struct async_event_handler_data -{ - async_event_handler_func* proc; - gdb_client_data client_data; -}; - -static void -invoke_async_event_handler (event_data data) -{ - struct async_event_handler_data *hdata = data.ptr; - async_event_handler_func* proc = hdata->proc; - gdb_client_data client_data = hdata->client_data; +/* Check if asynchronous event handlers are ready, and call the + handler function for one that is. */ - xfree (hdata); - (*proc) (client_data); -} - -/* Check if any asynchronous event handlers are ready, and queue - events in the ready queue for any that are. */ -static void +static int check_async_event_handlers (void) { async_event_handler *async_handler_ptr; - struct async_event_handler_data *hdata; - struct gdb_event *event_ptr; - event_data data; for (async_handler_ptr = async_event_handler_list.first_handler; async_handler_ptr != NULL; @@ -1092,18 +959,12 @@ check_async_event_handlers (void) if (async_handler_ptr->ready) { async_handler_ptr->ready = 0; - - hdata = xmalloc (sizeof (*hdata)); - - hdata->proc = async_handler_ptr->proc; - hdata->client_data = async_handler_ptr->client_data; - - data.ptr = hdata; - - event_ptr = create_event (invoke_async_event_handler, data); - QUEUE_enque (gdb_event_p, event_queue, event_ptr); + (*async_handler_ptr->proc) (async_handler_ptr->client_data); + return 1; } } + + return 0; } /* Delete an asynchronous handler (ASYNC_HANDLER_PTR). @@ -1236,49 +1097,13 @@ delete_timer (int id) gdb_notifier.timeout_valid = 0; } -/* When a timer event is put on the event queue, it will be handled by - this function. Just call the associated procedure and delete the - timer event from the event queue. Repeat this for each timer that - has expired. */ -static void -handle_timer_event (event_data dummy) -{ - struct timeval time_now; - struct gdb_timer *timer_ptr, *saved_timer; - - gettimeofday (&time_now, NULL); - timer_ptr = timer_list.first_timer; - - while (timer_ptr != NULL) - { - if ((timer_ptr->when.tv_sec > time_now.tv_sec) - || ((timer_ptr->when.tv_sec == time_now.tv_sec) - && (timer_ptr->when.tv_usec > time_now.tv_usec))) - break; - - /* Get rid of the timer from the beginning of the list. */ - timer_list.first_timer = timer_ptr->next; - saved_timer = timer_ptr; - timer_ptr = timer_ptr->next; - /* Call the procedure associated with that timer. */ - (*saved_timer->proc) (saved_timer->client_data); - xfree (saved_timer); - } - - gdb_notifier.timeout_valid = 0; -} +/* Update the timeout for the select() or poll(). Returns true if the + timer has already expired, false otherwise. */ -/* Check whether any timers in the timers queue are ready. If at least - one timer is ready, stick an event onto the event queue. Even in - case more than one timer is ready, one event is enough, because the - handle_timer_event() will go through the timers list and call the - procedures associated with all that have expired.l Update the - timeout for the select() or poll() as well. */ -static void -poll_timers (void) +static int +update_wait_timeout (void) { struct timeval time_now, delta; - gdb_event *event_ptr; if (timer_list.first_timer != NULL) { @@ -1292,27 +1117,18 @@ poll_timers (void) delta.tv_usec += 1000000; } - /* Oops it expired already. Tell select / poll to return - immediately. (Cannot simply test if delta.tv_sec is negative - because time_t might be unsigned.) */ + /* Cannot simply test if delta.tv_sec is negative because time_t + might be unsigned. */ if (timer_list.first_timer->when.tv_sec < time_now.tv_sec || (timer_list.first_timer->when.tv_sec == time_now.tv_sec && timer_list.first_timer->when.tv_usec < time_now.tv_usec)) { + /* It expired already. */ delta.tv_sec = 0; delta.tv_usec = 0; } - if (delta.tv_sec == 0 && delta.tv_usec == 0) - { - event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event)); - event_ptr->proc = handle_timer_event; - event_ptr->data.integer = timer_list.first_timer->timer_id; - QUEUE_enque (gdb_event_p, event_queue, event_ptr); - } - - /* Now we need to update the timeout for select/ poll, because - we don't want to sit there while this timer is expiring. */ + /* Update the timeout for select/ poll. */ if (use_poll) { #ifdef HAVE_POLL @@ -1328,7 +1144,43 @@ poll_timers (void) gdb_notifier.select_timeout.tv_usec = delta.tv_usec; } gdb_notifier.timeout_valid = 1; + + if (delta.tv_sec == 0 && delta.tv_usec == 0) + return 1; } else gdb_notifier.timeout_valid = 0; + + return 0; +} + +/* Check whether a timer in the timers queue is ready. If a timer is + ready, call its handler and return. Update the timeout for the + select() or poll() as well. Return 1 if an event was handled, + otherwise returns 0.*/ + +static int +poll_timers (void) +{ + if (update_wait_timeout ()) + { + struct gdb_timer *timer_ptr = timer_list.first_timer; + timer_handler_func *proc = timer_ptr->proc; + gdb_client_data client_data = timer_ptr->client_data; + + /* Get rid of the timer from the beginning of the list. */ + timer_list.first_timer = timer_ptr->next; + + /* Delete the timer before calling the callback, not after, in + case the callback itself decides to try deleting the timer + too. */ + xfree (timer_ptr); + + /* Call the procedure associated with that timer. */ + (proc) (client_data); + + return 1; + } + + return 0; } diff --git a/gdb/event-loop.h b/gdb/event-loop.h index b9338a2a47e..6ae4013b066 100644 --- a/gdb/event-loop.h +++ b/gdb/event-loop.h @@ -77,7 +77,6 @@ typedef void (timer_handler_func) (gdb_client_data); /* Exported functions from event-loop.c */ -extern void initialize_event_loop (void); extern void start_event_loop (void); extern int gdb_do_one_event (void); extern void delete_file_handler (int fd); diff --git a/gdb/top.c b/gdb/top.c index 000b14ed4ee..8242e12ab35 100644 --- a/gdb/top.c +++ b/gdb/top.c @@ -1953,7 +1953,6 @@ gdb_init (char *argv0) initialize_inferiors (); initialize_current_architecture (); init_cli_cmds(); - initialize_event_loop (); init_main (); /* But that omits this file! Do it now. */ initialize_stdin_serial (); |