| /* Event loop machinery for GDB, the GNU debugger. |
| Copyright 1999, 2000, 2001, 2002 Free Software Foundation, Inc. |
| Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #include "defs.h" |
| #include "event-loop.h" |
| #include "event-top.h" |
| |
| #ifdef HAVE_POLL |
| #if defined (HAVE_POLL_H) |
| #include <poll.h> |
| #elif defined (HAVE_SYS_POLL_H) |
| #include <sys/poll.h> |
| #endif |
| #endif |
| |
| #include <sys/types.h> |
| #include "gdb_string.h" |
| #include <errno.h> |
| #include <sys/time.h> |
| |
| typedef struct gdb_event gdb_event; |
| typedef void (event_handler_func) (int); |
| |
| /* Event for the GDB event system. Events are queued by calling |
| async_queue_event and serviced later on by gdb_do_one_event. An |
| event can be, for instance, a file descriptor becoming ready to be |
| read. Servicing an event simply means that the procedure PROC will |
| be called. We have 2 queues, one for file handlers that we listen |
| to in the event loop, and one for the file handlers+events that are |
| ready. The procedure PROC associated with each event is always the |
| same (handle_file_event). Its duty is to invoke the handler |
| associated with the file descriptor whose state change generated |
| the event, plus doing other cleanups and such. */ |
| |
| struct gdb_event |
| { |
| event_handler_func *proc; /* Procedure to call to service this event. */ |
| int fd; /* File descriptor that is ready. */ |
| struct gdb_event *next_event; /* Next in list of events or NULL. */ |
| }; |
| |
| /* Information about each file descriptor we register with the event |
| loop. */ |
| |
| typedef struct file_handler |
| { |
| int fd; /* File descriptor. */ |
| int mask; /* Events we want to monitor: POLLIN, etc. */ |
| int ready_mask; /* Events that have been seen since |
| the last time. */ |
| handler_func *proc; /* Procedure to call when fd is ready. */ |
| gdb_client_data client_data; /* Argument to pass to proc. */ |
| int error; /* Was an error detected on this fd? */ |
| struct file_handler *next_file; /* Next registered file descriptor. */ |
| } |
| file_handler; |
| |
| /* PROC is a function to be invoked when the READY flag is set. This |
| happens when there has been a signal and the corresponding signal |
| handler has 'triggered' this async_signal_handler for |
| execution. The actual work to be done in response to a signal will |
| be carried out by PROC at a later time, within process_event. This |
| provides a deferred execution of signal handlers. |
| Async_init_signals takes care of setting up such an |
| asyn_signal_handler for each interesting signal. */ |
| typedef struct async_signal_handler |
| { |
| int ready; /* If ready, call this handler from the main event loop, |
| using invoke_async_handler. */ |
| struct async_signal_handler *next_handler; /* Ptr to next handler */ |
| sig_handler_func *proc; /* Function to call to do the work */ |
| gdb_client_data client_data; /* Argument to async_handler_func */ |
| } |
| async_signal_handler; |
| |
| |
| /* Event queue: |
| - the first event in the queue is the head of the queue. |
| It will be the next to be serviced. |
| - the last event in the queue |
| |
| Events can be inserted at the front of the queue or at the end of |
| the queue. Events will be extracted from the queue for processing |
| starting from the head. Therefore, events inserted at the head of |
| the queue will be processed in a last in first out fashion, while |
| those inserted at the tail of the queue will be processed in a first |
| in first out manner. All the fields are NULL if the queue is |
| empty. */ |
| |
| static struct |
| { |
| gdb_event *first_event; /* First pending event */ |
| gdb_event *last_event; /* Last pending event */ |
| } |
| event_queue; |
| |
| /* 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 |
| that have the POLL function, the other for those that don't, and |
| only support SELECT. Each of the elements in the gdb_notifier list is |
| basically a description of what kind of events gdb is interested |
| in, for each fd. */ |
| |
| /* As of 1999-04-30 only the input file descriptor is registered with the |
| event loop. */ |
| |
| /* Do we use poll or select ? */ |
| #ifdef HAVE_POLL |
| #define USE_POLL 1 |
| #else |
| #define USE_POLL 0 |
| #endif /* HAVE_POLL */ |
| |
| static unsigned char use_poll = USE_POLL; |
| |
| static struct |
| { |
| /* Ptr to head of file handler list. */ |
| file_handler *first_file_handler; |
| |
| #ifdef HAVE_POLL |
| /* Ptr to array of pollfd structures. */ |
| struct pollfd *poll_fds; |
| |
| /* Timeout in milliseconds for calls to poll(). */ |
| int poll_timeout; |
| #endif |
| |
| /* Masks to be used in the next call to select. |
| Bits are set in response to calls to create_file_handler. */ |
| fd_set check_masks[3]; |
| |
| /* What file descriptors were found ready by select. */ |
| fd_set ready_masks[3]; |
| |
| /* Number of file descriptors to monitor. (for poll) */ |
| /* Number of valid bits (highest fd value + 1). (for select) */ |
| int num_fds; |
| |
| /* Time structure for calls to select(). */ |
| struct timeval select_timeout; |
| |
| /* Flag to tell whether the timeout should be used. */ |
| int timeout_valid; |
| } |
| gdb_notifier; |
| |
| /* Structure associated with a timer. PROC will be executed at the |
| first occasion after WHEN. */ |
| struct gdb_timer |
| { |
| struct timeval when; |
| int timer_id; |
| struct gdb_timer *next; |
| timer_handler_func *proc; /* Function to call to do the work */ |
| gdb_client_data client_data; /* Argument to async_handler_func */ |
| } |
| gdb_timer; |
| |
| /* List of currently active timers. It is sorted in order of |
| increasing timers. */ |
| static struct |
| { |
| /* Pointer to first in timer list. */ |
| struct gdb_timer *first_timer; |
| |
| /* Id of the last timer created. */ |
| int num_timers; |
| } |
| timer_list; |
| |
| /* All the async_signal_handlers gdb is interested in are kept onto |
| this list. */ |
| static struct |
| { |
| /* Pointer to first in handler list. */ |
| async_signal_handler *first_handler; |
| |
| /* Pointer to last in handler list. */ |
| async_signal_handler *last_handler; |
| } |
| sighandler_list; |
| |
| /* Are any of the handlers ready? Check this variable using |
| check_async_ready. This is used by process_event, to determine |
| whether or not to invoke the invoke_async_signal_handler |
| function. */ |
| static int async_handler_ready = 0; |
| |
| static void create_file_handler (int fd, int mask, handler_func * proc, gdb_client_data client_data); |
| static void invoke_async_signal_handler (void); |
| static void handle_file_event (int event_file_desc); |
| static int gdb_wait_for_event (void); |
| static int check_async_ready (void); |
| static void async_queue_event (gdb_event * event_ptr, queue_position position); |
| static gdb_event *create_file_event (int fd); |
| static int process_event (void); |
| static void handle_timer_event (int dummy); |
| static void poll_timers (void); |
| |
| |
| /* Insert an event object into the gdb event queue at |
| the specified position. |
| POSITION can be head or tail, with values TAIL, HEAD. |
| EVENT_PTR points to the event to be inserted into the queue. |
| The caller must allocate memory for the event. It is freed |
| after the event has ben handled. |
| Events in the queue will be processed head to tail, therefore, |
| events inserted at the head of the queue will be processed |
| as last in first out. Event appended at the tail of the queue |
| will be processed first in first out. */ |
| static void |
| async_queue_event (gdb_event * event_ptr, queue_position position) |
| { |
| if (position == TAIL) |
| { |
| /* The event will become the new last_event. */ |
| |
| event_ptr->next_event = NULL; |
| if (event_queue.first_event == NULL) |
| event_queue.first_event = event_ptr; |
| else |
| event_queue.last_event->next_event = event_ptr; |
| event_queue.last_event = event_ptr; |
| } |
| else if (position == HEAD) |
| { |
| /* The event becomes the new first_event. */ |
| |
| event_ptr->next_event = event_queue.first_event; |
| if (event_queue.first_event == NULL) |
| event_queue.last_event = event_ptr; |
| event_queue.first_event = event_ptr; |
| } |
| } |
| |
| /* 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) |
| { |
| gdb_event *file_event_ptr; |
| |
| file_event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event)); |
| file_event_ptr->proc = handle_file_event; |
| file_event_ptr->fd = fd; |
| return (file_event_ptr); |
| } |
| |
| /* 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) |
| { |
| gdb_event *event_ptr, *prev_ptr; |
| event_handler_func *proc; |
| int fd; |
| |
| /* 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 (check_async_ready ()) |
| { |
| invoke_async_signal_handler (); |
| return 1; |
| } |
| |
| /* Look in the event queue to find an event that is ready |
| to be processed. */ |
| |
| for (event_ptr = event_queue.first_event; event_ptr != NULL; |
| event_ptr = event_ptr->next_event) |
| { |
| /* Call the handler for the event. */ |
| |
| proc = event_ptr->proc; |
| fd = event_ptr->fd; |
| |
| /* 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. */ |
| |
| if (event_queue.first_event == event_ptr) |
| { |
| event_queue.first_event = event_ptr->next_event; |
| if (event_ptr->next_event == NULL) |
| event_queue.last_event = NULL; |
| } |
| else |
| { |
| prev_ptr = event_queue.first_event; |
| while (prev_ptr->next_event != event_ptr) |
| prev_ptr = prev_ptr->next_event; |
| |
| prev_ptr->next_event = event_ptr->next_event; |
| if (event_ptr->next_event == NULL) |
| event_queue.last_event = prev_ptr; |
| } |
| xfree (event_ptr); |
| |
| /* Now call the procedure associated with the event. */ |
| (*proc) (fd); |
| 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 |
| can happen if there are no event sources to wait for). If an error |
| occurs catch_errors() which calls this function returns zero. */ |
| |
| int |
| gdb_do_one_event (void *data) |
| { |
| /* Any events already waiting in the queue? */ |
| if (process_event ()) |
| { |
| return 1; |
| } |
| |
| /* Are any timers that are ready? If so, put an event on the queue. */ |
| poll_timers (); |
| |
| /* Wait for a new event. If gdb_wait_for_event returns -1, |
| we should get out because this means that there are no |
| event sources left. This will make the event loop stop, |
| and the application exit. */ |
| |
| if (gdb_wait_for_event () < 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; |
| } |
| |
| /* Start up the event loop. This is the entry point to the event loop |
| from the command loop. */ |
| |
| void |
| start_event_loop (void) |
| { |
| /* Loop until there is nothing to do. This is the entry point to the |
| event loop engine. gdb_do_one_event, called via catch_errors() |
| will process one event for each invocation. It blocks waits for |
| an event and then processes it. >0 when an event is processed, 0 |
| when catch_errors() caught an error and <0 when there are no |
| longer any event sources registered. */ |
| while (1) |
| { |
| int gdb_result; |
| |
| gdb_result = catch_errors (gdb_do_one_event, 0, "", RETURN_MASK_ALL); |
| if (gdb_result < 0) |
| break; |
| |
| /* If we long-jumped out of do_one_event, we probably |
| didn't get around to resetting the prompt, which leaves |
| readline in a messed-up state. Reset it here. */ |
| |
| if (gdb_result == 0) |
| { |
| /* FIXME: this should really be a call to a hook that is |
| interface specific, because interfaces can display the |
| prompt in their own way. */ |
| display_gdb_prompt (0); |
| /* This call looks bizarre, but it is required. If the user |
| entered a command that caused an error, |
| after_char_processing_hook won't be called from |
| rl_callback_read_char_wrapper. Using a cleanup there |
| won't work, since we want this function to be called |
| after a new prompt is printed. */ |
| if (after_char_processing_hook) |
| (*after_char_processing_hook) (); |
| /* Maybe better to set a flag to be checked somewhere as to |
| whether display the prompt or not. */ |
| } |
| } |
| |
| /* We are done with the event loop. There are no more event sources |
| to listen to. So we exit GDB. */ |
| return; |
| } |
| |
| |
| /* Wrapper function for create_file_handler, so that the caller |
| doesn't have to know implementation details about the use of poll |
| vs. select. */ |
| void |
| add_file_handler (int fd, handler_func * proc, gdb_client_data client_data) |
| { |
| #ifdef HAVE_POLL |
| struct pollfd fds; |
| #endif |
| |
| if (use_poll) |
| { |
| #ifdef HAVE_POLL |
| /* Check to see if poll () is usable. If not, we'll switch to |
| use select. This can happen on systems like |
| m68k-motorola-sys, `poll' cannot be used to wait for `stdin'. |
| On m68k-motorola-sysv, tty's are not stream-based and not |
| `poll'able. */ |
| fds.fd = fd; |
| fds.events = POLLIN; |
| if (poll (&fds, 1, 0) == 1 && (fds.revents & POLLNVAL)) |
| use_poll = 0; |
| #else |
| internal_error (__FILE__, __LINE__, |
| "use_poll without HAVE_POLL"); |
| #endif /* HAVE_POLL */ |
| } |
| if (use_poll) |
| { |
| #ifdef HAVE_POLL |
| create_file_handler (fd, POLLIN, proc, client_data); |
| #else |
| internal_error (__FILE__, __LINE__, |
| "use_poll without HAVE_POLL"); |
| #endif |
| } |
| else |
| create_file_handler (fd, GDB_READABLE | GDB_EXCEPTION, proc, client_data); |
| } |
| |
| /* Add a file handler/descriptor to the list of descriptors we are |
| interested in. |
| FD is the file descriptor for the file/stream to be listened to. |
| For the poll case, MASK is a combination (OR) of |
| POLLIN, POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM, |
| POLLWRBAND: these are the events we are interested in. If any of them |
| occurs, proc should be called. |
| For the select case, MASK is a combination of READABLE, WRITABLE, EXCEPTION. |
| PROC is the procedure that will be called when an event occurs for |
| FD. CLIENT_DATA is the argument to pass to PROC. */ |
| static void |
| create_file_handler (int fd, int mask, handler_func * proc, gdb_client_data client_data) |
| { |
| file_handler *file_ptr; |
| |
| /* Do we already have a file handler for this file? (We may be |
| changing its associated procedure). */ |
| for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; |
| file_ptr = file_ptr->next_file) |
| { |
| if (file_ptr->fd == fd) |
| break; |
| } |
| |
| /* It is a new file descriptor. Add it to the list. Otherwise, just |
| change the data associated with it. */ |
| if (file_ptr == NULL) |
| { |
| file_ptr = (file_handler *) xmalloc (sizeof (file_handler)); |
| file_ptr->fd = fd; |
| file_ptr->ready_mask = 0; |
| file_ptr->next_file = gdb_notifier.first_file_handler; |
| gdb_notifier.first_file_handler = file_ptr; |
| |
| if (use_poll) |
| { |
| #ifdef HAVE_POLL |
| gdb_notifier.num_fds++; |
| if (gdb_notifier.poll_fds) |
| gdb_notifier.poll_fds = |
| (struct pollfd *) xrealloc (gdb_notifier.poll_fds, |
| (gdb_notifier.num_fds |
| * sizeof (struct pollfd))); |
| else |
| gdb_notifier.poll_fds = |
| (struct pollfd *) xmalloc (sizeof (struct pollfd)); |
| (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->fd = fd; |
| (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->events = mask; |
| (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->revents = 0; |
| #else |
| internal_error (__FILE__, __LINE__, |
| "use_poll without HAVE_POLL"); |
| #endif /* HAVE_POLL */ |
| } |
| else |
| { |
| if (mask & GDB_READABLE) |
| FD_SET (fd, &gdb_notifier.check_masks[0]); |
| else |
| FD_CLR (fd, &gdb_notifier.check_masks[0]); |
| |
| if (mask & GDB_WRITABLE) |
| FD_SET (fd, &gdb_notifier.check_masks[1]); |
| else |
| FD_CLR (fd, &gdb_notifier.check_masks[1]); |
| |
| if (mask & GDB_EXCEPTION) |
| FD_SET (fd, &gdb_notifier.check_masks[2]); |
| else |
| FD_CLR (fd, &gdb_notifier.check_masks[2]); |
| |
| if (gdb_notifier.num_fds <= fd) |
| gdb_notifier.num_fds = fd + 1; |
| } |
| } |
| |
| file_ptr->proc = proc; |
| file_ptr->client_data = client_data; |
| file_ptr->mask = mask; |
| } |
| |
| /* Remove the file descriptor FD from the list of monitored fd's: |
| i.e. we don't care anymore about events on the FD. */ |
| void |
| delete_file_handler (int fd) |
| { |
| file_handler *file_ptr, *prev_ptr = NULL; |
| int i; |
| #ifdef HAVE_POLL |
| int j; |
| struct pollfd *new_poll_fds; |
| #endif |
| |
| /* Find the entry for the given file. */ |
| |
| for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; |
| file_ptr = file_ptr->next_file) |
| { |
| if (file_ptr->fd == fd) |
| break; |
| } |
| |
| if (file_ptr == NULL) |
| return; |
| |
| if (use_poll) |
| { |
| #ifdef HAVE_POLL |
| /* Create a new poll_fds array by copying every fd's information but the |
| one we want to get rid of. */ |
| |
| new_poll_fds = |
| (struct pollfd *) xmalloc ((gdb_notifier.num_fds - 1) * sizeof (struct pollfd)); |
| |
| for (i = 0, j = 0; i < gdb_notifier.num_fds; i++) |
| { |
| if ((gdb_notifier.poll_fds + i)->fd != fd) |
| { |
| (new_poll_fds + j)->fd = (gdb_notifier.poll_fds + i)->fd; |
| (new_poll_fds + j)->events = (gdb_notifier.poll_fds + i)->events; |
| (new_poll_fds + j)->revents = (gdb_notifier.poll_fds + i)->revents; |
| j++; |
| } |
| } |
| xfree (gdb_notifier.poll_fds); |
| gdb_notifier.poll_fds = new_poll_fds; |
| gdb_notifier.num_fds--; |
| #else |
| internal_error (__FILE__, __LINE__, |
| "use_poll without HAVE_POLL"); |
| #endif /* HAVE_POLL */ |
| } |
| else |
| { |
| if (file_ptr->mask & GDB_READABLE) |
| FD_CLR (fd, &gdb_notifier.check_masks[0]); |
| if (file_ptr->mask & GDB_WRITABLE) |
| FD_CLR (fd, &gdb_notifier.check_masks[1]); |
| if (file_ptr->mask & GDB_EXCEPTION) |
| FD_CLR (fd, &gdb_notifier.check_masks[2]); |
| |
| /* Find current max fd. */ |
| |
| if ((fd + 1) == gdb_notifier.num_fds) |
| { |
| gdb_notifier.num_fds--; |
| for (i = gdb_notifier.num_fds; i; i--) |
| { |
| if (FD_ISSET (i - 1, &gdb_notifier.check_masks[0]) |
| || FD_ISSET (i - 1, &gdb_notifier.check_masks[1]) |
| || FD_ISSET (i - 1, &gdb_notifier.check_masks[2])) |
| break; |
| } |
| gdb_notifier.num_fds = i; |
| } |
| } |
| |
| /* Deactivate the file descriptor, by clearing its mask, |
| so that it will not fire again. */ |
| |
| file_ptr->mask = 0; |
| |
| /* Get rid of the file handler in the file handler list. */ |
| if (file_ptr == gdb_notifier.first_file_handler) |
| gdb_notifier.first_file_handler = file_ptr->next_file; |
| else |
| { |
| for (prev_ptr = gdb_notifier.first_file_handler; |
| prev_ptr->next_file != file_ptr; |
| prev_ptr = prev_ptr->next_file) |
| ; |
| prev_ptr->next_file = file_ptr->next_file; |
| } |
| xfree (file_ptr); |
| } |
| |
| /* 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. */ |
| static void |
| handle_file_event (int event_file_desc) |
| { |
| file_handler *file_ptr; |
| int mask; |
| #ifdef HAVE_POLL |
| int error_mask; |
| int error_mask_returned; |
| #endif |
| |
| /* 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 cannot |
| be used in the requested event mask (events), but they |
| can be returned in the return mask (revents). We need to |
| check for those event too, and add them to the mask which |
| will be passed to the handler. */ |
| |
| /* See if the desired events (mask) match the received |
| events (ready_mask). */ |
| |
| if (use_poll) |
| { |
| #ifdef HAVE_POLL |
| error_mask = POLLHUP | POLLERR | POLLNVAL; |
| mask = (file_ptr->ready_mask & file_ptr->mask) | |
| (file_ptr->ready_mask & error_mask); |
| error_mask_returned = mask & error_mask; |
| |
| if (error_mask_returned != 0) |
| { |
| /* Work in progress. We may need to tell somebody what |
| kind of error we had. */ |
| if (error_mask_returned & POLLHUP) |
| printf_unfiltered ("Hangup detected on fd %d\n", file_ptr->fd); |
| if (error_mask_returned & POLLERR) |
| printf_unfiltered ("Error detected on fd %d\n", file_ptr->fd); |
| if (error_mask_returned & POLLNVAL) |
| printf_unfiltered ("Invalid or non-`poll'able fd %d\n", file_ptr->fd); |
| file_ptr->error = 1; |
| } |
| else |
| file_ptr->error = 0; |
| #else |
| internal_error (__FILE__, __LINE__, |
| "use_poll without HAVE_POLL"); |
| #endif /* HAVE_POLL */ |
| } |
| else |
| { |
| if (file_ptr->ready_mask & GDB_EXCEPTION) |
| { |
| printf_unfiltered ("Exception condition detected on fd %d\n", file_ptr->fd); |
| file_ptr->error = 1; |
| } |
| else |
| file_ptr->error = 0; |
| mask = file_ptr->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 there are no events, this function will block in the |
| call to poll. |
| Return -1 if there are no files descriptors to monitor, |
| otherwise return 0. */ |
| static int |
| gdb_wait_for_event (void) |
| { |
| file_handler *file_ptr; |
| gdb_event *file_event_ptr; |
| int num_found = 0; |
| int i; |
| |
| /* Make sure all output is done before getting another event. */ |
| gdb_flush (gdb_stdout); |
| gdb_flush (gdb_stderr); |
| |
| if (gdb_notifier.num_fds == 0) |
| return -1; |
| |
| if (use_poll) |
| { |
| #ifdef HAVE_POLL |
| num_found = |
| poll (gdb_notifier.poll_fds, |
| (unsigned long) gdb_notifier.num_fds, |
| gdb_notifier.timeout_valid ? gdb_notifier.poll_timeout : -1); |
| |
| /* Don't print anything if we get out of poll because of a |
| signal. */ |
| if (num_found == -1 && errno != EINTR) |
| perror_with_name ("Poll"); |
| #else |
| internal_error (__FILE__, __LINE__, |
| "use_poll without HAVE_POLL"); |
| #endif /* HAVE_POLL */ |
| } |
| else |
| { |
| gdb_notifier.ready_masks[0] = gdb_notifier.check_masks[0]; |
| gdb_notifier.ready_masks[1] = gdb_notifier.check_masks[1]; |
| gdb_notifier.ready_masks[2] = gdb_notifier.check_masks[2]; |
| num_found = select (gdb_notifier.num_fds, |
| &gdb_notifier.ready_masks[0], |
| &gdb_notifier.ready_masks[1], |
| &gdb_notifier.ready_masks[2], |
| gdb_notifier.timeout_valid |
| ? &gdb_notifier.select_timeout : NULL); |
| |
| /* Clear the masks after an error from select. */ |
| if (num_found == -1) |
| { |
| FD_ZERO (&gdb_notifier.ready_masks[0]); |
| FD_ZERO (&gdb_notifier.ready_masks[1]); |
| FD_ZERO (&gdb_notifier.ready_masks[2]); |
| /* Dont print anything is we got a signal, let gdb handle it. */ |
| if (errno != EINTR) |
| perror_with_name ("Select"); |
| } |
| } |
| |
| /* Enqueue all detected file events. */ |
| |
| if (use_poll) |
| { |
| #ifdef HAVE_POLL |
| for (i = 0; (i < gdb_notifier.num_fds) && (num_found > 0); i++) |
| { |
| if ((gdb_notifier.poll_fds + i)->revents) |
| num_found--; |
| else |
| continue; |
| |
| for (file_ptr = gdb_notifier.first_file_handler; |
| file_ptr != NULL; |
| file_ptr = file_ptr->next_file) |
| { |
| if (file_ptr->fd == (gdb_notifier.poll_fds + i)->fd) |
| break; |
| } |
| |
| 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); |
| async_queue_event (file_event_ptr, TAIL); |
| } |
| } |
| |
| file_ptr->ready_mask = (gdb_notifier.poll_fds + i)->revents; |
| } |
| #else |
| internal_error (__FILE__, __LINE__, |
| "use_poll without HAVE_POLL"); |
| #endif /* HAVE_POLL */ |
| } |
| else |
| { |
| for (file_ptr = gdb_notifier.first_file_handler; |
| (file_ptr != NULL) && (num_found > 0); |
| file_ptr = file_ptr->next_file) |
| { |
| int mask = 0; |
| |
| if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[0])) |
| mask |= GDB_READABLE; |
| if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[1])) |
| mask |= GDB_WRITABLE; |
| if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[2])) |
| mask |= GDB_EXCEPTION; |
| |
| if (!mask) |
| continue; |
| 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); |
| async_queue_event (file_event_ptr, TAIL); |
| } |
| file_ptr->ready_mask = mask; |
| } |
| } |
| return 0; |
| } |
| |
| |
| /* Create an asynchronous handler, allocating memory for it. |
| Return a pointer to the newly created handler. |
| This pointer will be used to invoke the handler by |
| invoke_async_signal_handler. |
| PROC is the function to call with CLIENT_DATA argument |
| whenever the handler is invoked. */ |
| async_signal_handler * |
| create_async_signal_handler (sig_handler_func * proc, gdb_client_data client_data) |
| { |
| async_signal_handler *async_handler_ptr; |
| |
| async_handler_ptr = |
| (async_signal_handler *) xmalloc (sizeof (async_signal_handler)); |
| async_handler_ptr->ready = 0; |
| async_handler_ptr->next_handler = NULL; |
| async_handler_ptr->proc = proc; |
| async_handler_ptr->client_data = client_data; |
| if (sighandler_list.first_handler == NULL) |
| sighandler_list.first_handler = async_handler_ptr; |
| else |
| sighandler_list.last_handler->next_handler = async_handler_ptr; |
| sighandler_list.last_handler = async_handler_ptr; |
| return async_handler_ptr; |
| } |
| |
| /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information will |
| be used when the handlers are invoked, after we have waited for |
| some event. The caller of this function is the interrupt handler |
| associated with a signal. */ |
| void |
| mark_async_signal_handler (async_signal_handler * async_handler_ptr) |
| { |
| ((async_signal_handler *) async_handler_ptr)->ready = 1; |
| async_handler_ready = 1; |
| } |
| |
| /* Call all the handlers that are ready. */ |
| static void |
| invoke_async_signal_handler (void) |
| { |
| async_signal_handler *async_handler_ptr; |
| |
| if (async_handler_ready == 0) |
| return; |
| async_handler_ready = 0; |
| |
| /* Invoke ready handlers. */ |
| |
| while (1) |
| { |
| for (async_handler_ptr = sighandler_list.first_handler; |
| async_handler_ptr != NULL; |
| async_handler_ptr = async_handler_ptr->next_handler) |
| { |
| if (async_handler_ptr->ready) |
| break; |
| } |
| if (async_handler_ptr == NULL) |
| break; |
| async_handler_ptr->ready = 0; |
| (*async_handler_ptr->proc) (async_handler_ptr->client_data); |
| } |
| |
| return; |
| } |
| |
| /* Delete an asynchronous handler (ASYNC_HANDLER_PTR). |
| Free the space allocated for it. */ |
| void |
| delete_async_signal_handler (async_signal_handler ** async_handler_ptr) |
| { |
| async_signal_handler *prev_ptr; |
| |
| if (sighandler_list.first_handler == (*async_handler_ptr)) |
| { |
| sighandler_list.first_handler = (*async_handler_ptr)->next_handler; |
| if (sighandler_list.first_handler == NULL) |
| sighandler_list.last_handler = NULL; |
| } |
| else |
| { |
| prev_ptr = sighandler_list.first_handler; |
| while (prev_ptr->next_handler != (*async_handler_ptr) && prev_ptr) |
| prev_ptr = prev_ptr->next_handler; |
| prev_ptr->next_handler = (*async_handler_ptr)->next_handler; |
| if (sighandler_list.last_handler == (*async_handler_ptr)) |
| sighandler_list.last_handler = prev_ptr; |
| } |
| xfree ((*async_handler_ptr)); |
| (*async_handler_ptr) = NULL; |
| } |
| |
| /* Is it necessary to call invoke_async_signal_handler? */ |
| static int |
| check_async_ready (void) |
| { |
| return async_handler_ready; |
| } |
| |
| /* Create a timer that will expire in MILLISECONDS from now. When the |
| timer is ready, PROC will be executed. At creation, the timer is |
| aded to the timers queue. This queue is kept sorted in order of |
| increasing timers. Return a handle to the timer struct. */ |
| int |
| create_timer (int milliseconds, timer_handler_func * proc, gdb_client_data client_data) |
| { |
| struct gdb_timer *timer_ptr, *timer_index, *prev_timer; |
| struct timeval time_now, delta; |
| |
| /* compute seconds */ |
| delta.tv_sec = milliseconds / 1000; |
| /* compute microseconds */ |
| delta.tv_usec = (milliseconds % 1000) * 1000; |
| |
| gettimeofday (&time_now, NULL); |
| |
| timer_ptr = (struct gdb_timer *) xmalloc (sizeof (gdb_timer)); |
| timer_ptr->when.tv_sec = time_now.tv_sec + delta.tv_sec; |
| timer_ptr->when.tv_usec = time_now.tv_usec + delta.tv_usec; |
| /* carry? */ |
| if (timer_ptr->when.tv_usec >= 1000000) |
| { |
| timer_ptr->when.tv_sec += 1; |
| timer_ptr->when.tv_usec -= 1000000; |
| } |
| timer_ptr->proc = proc; |
| timer_ptr->client_data = client_data; |
| timer_list.num_timers++; |
| timer_ptr->timer_id = timer_list.num_timers; |
| |
| /* Now add the timer to the timer queue, making sure it is sorted in |
| increasing order of expiration. */ |
| |
| for (timer_index = timer_list.first_timer; |
| timer_index != NULL; |
| timer_index = timer_index->next) |
| { |
| /* If the seconds field is greater or if it is the same, but the |
| microsecond field is greater. */ |
| if ((timer_index->when.tv_sec > timer_ptr->when.tv_sec) || |
| ((timer_index->when.tv_sec == timer_ptr->when.tv_sec) |
| && (timer_index->when.tv_usec > timer_ptr->when.tv_usec))) |
| break; |
| } |
| |
| if (timer_index == timer_list.first_timer) |
| { |
| timer_ptr->next = timer_list.first_timer; |
| timer_list.first_timer = timer_ptr; |
| |
| } |
| else |
| { |
| for (prev_timer = timer_list.first_timer; |
| prev_timer->next != timer_index; |
| prev_timer = prev_timer->next) |
| ; |
| |
| prev_timer->next = timer_ptr; |
| timer_ptr->next = timer_index; |
| } |
| |
| gdb_notifier.timeout_valid = 0; |
| return timer_ptr->timer_id; |
| } |
| |
| /* There is a chance that the creator of the timer wants to get rid of |
| it before it expires. */ |
| void |
| delete_timer (int id) |
| { |
| struct gdb_timer *timer_ptr, *prev_timer = NULL; |
| |
| /* Find the entry for the given timer. */ |
| |
| for (timer_ptr = timer_list.first_timer; timer_ptr != NULL; |
| timer_ptr = timer_ptr->next) |
| { |
| if (timer_ptr->timer_id == id) |
| break; |
| } |
| |
| if (timer_ptr == NULL) |
| return; |
| /* Get rid of the timer in the timer list. */ |
| if (timer_ptr == timer_list.first_timer) |
| timer_list.first_timer = timer_ptr->next; |
| else |
| { |
| for (prev_timer = timer_list.first_timer; |
| prev_timer->next != timer_ptr; |
| prev_timer = prev_timer->next) |
| ; |
| prev_timer->next = timer_ptr->next; |
| } |
| xfree (timer_ptr); |
| |
| 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 assiciated procedure and delete the |
| timer event from the event queue. Repeat this for each timer that |
| has expired. */ |
| static void |
| handle_timer_event (int 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; |
| } |
| |
| /* 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. Update the |
| timeout for the select() or poll() as well. */ |
| static void |
| poll_timers (void) |
| { |
| struct timeval time_now, delta; |
| gdb_event *event_ptr; |
| |
| if (timer_list.first_timer != NULL) |
| { |
| gettimeofday (&time_now, NULL); |
| delta.tv_sec = timer_list.first_timer->when.tv_sec - time_now.tv_sec; |
| delta.tv_usec = timer_list.first_timer->when.tv_usec - time_now.tv_usec; |
| /* borrow? */ |
| if (delta.tv_usec < 0) |
| { |
| delta.tv_sec -= 1; |
| 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.) */ |
| 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)) |
| { |
| 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->fd = timer_list.first_timer->timer_id; |
| async_queue_event (event_ptr, TAIL); |
| } |
| |
| /* Now we need to update the timeout for select/ poll, because we |
| don't want to sit there while this timer is expiring. */ |
| if (use_poll) |
| { |
| #ifdef HAVE_POLL |
| gdb_notifier.poll_timeout = delta.tv_sec * 1000; |
| #else |
| internal_error (__FILE__, __LINE__, |
| "use_poll without HAVE_POLL"); |
| #endif /* HAVE_POLL */ |
| } |
| else |
| { |
| gdb_notifier.select_timeout.tv_sec = delta.tv_sec; |
| gdb_notifier.select_timeout.tv_usec = delta.tv_usec; |
| } |
| gdb_notifier.timeout_valid = 1; |
| } |
| else |
| gdb_notifier.timeout_valid = 0; |
| } |