X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fevent-loop.c;h=7934ab4c82f8276058576bdf7c71d616fa817f8f;hb=e2882c85786571175a0b0bfc3bcd2f14620b1ea3;hp=4d35ed785da1d85164c6fcf9efb7e21ae86ab1e5;hpb=30727aa6d12fb866494020c0b62ab265a2bdcdfe;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/event-loop.c b/gdb/event-loop.c index 4d35ed785d..7934ab4c82 100644 --- a/gdb/event-loop.c +++ b/gdb/event-loop.c @@ -1,12 +1,12 @@ /* Event loop machinery for GDB, the GNU debugger. - Copyright 1999 Free Software Foundation, Inc. + Copyright (C) 1999-2018 Free Software Foundation, Inc. Written by Elena Zannoni 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 + the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, @@ -15,344 +15,460 @@ 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. */ + along with this program. If not, see . */ #include "defs.h" -#include "top.h" #include "event-loop.h" +#include "event-top.h" +#include "queue.h" +#include "ser-event.h" + #ifdef HAVE_POLL +#if defined (HAVE_POLL_H) #include -#else -#include +#elif defined (HAVE_SYS_POLL_H) +#include +#endif #endif -#include -#include - -/* 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 +#include +#include "gdb_sys_time.h" +#include "gdb_select.h" +#include "observer.h" +#include "top.h" + +/* Tell create_file_handler what events we are interested in. + This is used by the select version of the event loop. */ + +#define GDB_READABLE (1<<1) +#define GDB_WRITABLE (1<<2) +#define GDB_EXCEPTION (1<<3) + +/* Data point to pass to the event handler. */ +typedef union event_data +{ + void *ptr; + int integer; +} event_data; + +typedef struct gdb_event gdb_event; +typedef void (event_handler_func) (event_data); + +/* 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 dependant + of the event source. In the case of monitored file descriptors, it + 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. In the + case of async signal handlers, it is + invoke_async_signal_handler. */ + +typedef struct gdb_event { - gdb_event *first_event; /* First pending event */ - gdb_event *last_event; /* Last pending event */ + /* Procedure to call to service this event. */ + event_handler_func *proc; + + /* Data to pass to the event handler. */ + event_data data; + } *gdb_event_p; + +/* 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 + async_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. */ } -event_queue; +async_signal_handler; + +/* PROC is a function to be invoked when the READY flag is set. This + happens when the event has been marked with + MARK_ASYNC_EVENT_HANDLER. The actual work to be done in response + to an event will be carried out by PROC at a later time, within + process_event. This provides a deferred execution of event + handlers. */ +typedef struct async_event_handler + { + /* If ready, call this handler from the main event loop, using + invoke_event_handler. */ + int ready; + + /* Point to next handler. */ + struct async_event_handler *next_handler; + + /* Function to call to do the work. */ + async_event_handler_func *proc; + + /* Argument to PROC. */ + gdb_client_data client_data; + } +async_event_handler; /* 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 + 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 + 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. */ + in, for each fd. */ /* As of 1999-04-30 only the input file descriptor is registered with the - event loop. */ + event loop. */ +/* Do we use poll or select ? */ #ifdef HAVE_POLL -/* Poll based implementation of the notifier. */ +#define USE_POLL 1 +#else +#define USE_POLL 0 +#endif /* HAVE_POLL */ + +static unsigned char use_poll = USE_POLL; + +#ifdef USE_WIN32API +#include +#include +#endif static struct { - /* Ptr to head of file handler list. */ + /* Ptr to head of file handler list. */ file_handler *first_file_handler; - /* Ptr to array of pollfd structures. */ - struct pollfd *poll_fds; - - /* Number of file descriptors to monitor. */ - int num_fds; + /* Next file handler to handle, for the select variant. To level + the fairness across event sources, we serve file handlers in a + round-robin-like fashion. The number and order of the polled + file handlers may change between invocations, but this is good + enough. */ + file_handler *next_file_handler; - } -gdb_notifier; - -#else /* ! HAVE_POLL */ +#ifdef HAVE_POLL + /* Ptr to array of pollfd structures. */ + struct pollfd *poll_fds; -/* Select based implementation of the notifier. */ + /* Next file descriptor to handle, for the poll variant. To level + the fairness across event sources, we poll the file descriptors + in a round-robin-like fashion. The number and order of the + polled file descriptors may change between invocations, but + this is good enough. */ + int next_poll_fds_index; -static struct - { - /* Ptr to head of file handler list. */ - file_handler *first_file_handler; + /* 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_mask check_masks[3 * MASK_SIZE]; + 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_mask ready_masks[3 * MASK_SIZE]; + /* What file descriptors were found ready by select. */ + fd_set ready_masks[3]; - /* Number of valid bits (highest fd value + 1). */ + /* 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; -#endif /* HAVE_POLL */ +/* Structure associated with a timer. PROC will be executed at the + first occasion after WHEN. */ +struct gdb_timer + { + std::chrono::steady_clock::time_point 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. */ + }; + +/* 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. */ + this list. */ static struct { - /* Pointer to first in handler list. */ + /* Pointer to first in handler list. */ async_signal_handler *first_handler; - /* Pointer to last in handler list. */ + /* Pointer to last in handler list. */ async_signal_handler *last_handler; } sighandler_list; -/* Is 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 PARAMS ((int, int, file_handler_func *, gdb_client_data)); -static void invoke_async_signal_handler PARAMS ((void)); -static int gdb_wait_for_event PARAMS ((void)); -static int gdb_do_one_event PARAMS ((void)); -static int check_async_ready PARAMS ((void)); +/* All the async_event_handlers gdb is interested in are kept onto + this list. */ +static struct + { + /* Pointer to first in handler list. */ + async_event_handler *first_handler; + + /* Pointer to last in handler list. */ + async_event_handler *last_handler; + } +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 int check_async_event_handlers (void); +static int gdb_wait_for_event (int); +static int update_wait_timeout (void); +static int 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 (event_ptr, position) - gdb_event *event_ptr; - queue_position position; -{ - if (position == TAIL) - { - /* The event will become the new last_event. */ +/* This event is signalled whenever an asynchronous handler needs to + defer an action to the event loop. */ +static struct serial_event *async_signal_handlers_serial_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. */ +/* Callback registered with ASYNC_SIGNAL_HANDLERS_SERIAL_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; - } +static void +async_signals_handler (int error, gdb_client_data client_data) +{ + /* Do nothing. Handlers are run by invoke_async_signal_handlers + from instead. */ } -/* 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 +initialize_async_signal_handlers (void) { - gdb_event *event_ptr, *prev_ptr; - event_handler_func *proc; - int fd; + async_signal_handlers_serial_event = make_serial_event (); - /* 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; - } + add_file_handler (serial_event_fd (async_signal_handlers_serial_event), + async_signals_handler, NULL); +} - /* Look in the event queue to find an event that is ready - to be processed. */ +/* 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). */ - for (event_ptr = event_queue.first_event; event_ptr != NULL; - event_ptr = event_ptr->next_event) +int +gdb_do_one_event (void) +{ + static int event_source_head = 0; + const int number_of_sources = 3; + int current = 0; + + /* 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++) { - /* Call the handler for the event. */ - - proc = event_ptr->proc; - fd = event_ptr->fd; + int res; - /* 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) + switch (event_source_head) { - event_queue.first_event = event_ptr->next_event; - if (event_ptr->next_event == NULL) - event_queue.last_event = NULL; + case 0: + /* 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? */ + res = gdb_wait_for_event (0); + break; + case 2: + /* Are there any asynchronous event handlers ready? */ + res = check_async_event_handlers (); + break; + default: + internal_error (__FILE__, __LINE__, + "unexpected event_source_head %d", + event_source_head); } - 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; - } - free ((char *) event_ptr); + event_source_head++; + if (event_source_head == number_of_sources) + event_source_head = 0; - /* Now call the procedure associted with the event. */ - (*proc) (fd); - return 1; + if (res > 0) + return 1; } - /* this is the case if there are no event on the event queue. */ - return 0; + /* 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 + sources left. This will make the event loop stop, and the + application exit. */ + + if (gdb_wait_for_event (1) < 0) + 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; } -/* 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 1 if something was done otherwise returns 0 (this can - happen if there are no event sources to wait for). */ -static int -gdb_do_one_event () -{ - int result = 0; +/* 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 will process one event + for each invocation. It blocks waiting for an event and then + processes it. */ while (1) { - if (!SET_TOP_LEVEL ()) - { - /* Any events already waiting in the queue? */ - if (process_event ()) - { - result = 1; - break; - } - - /* 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. */ - - result = gdb_wait_for_event (); - if (result < 0) - { - result = 0; - break; - } - - /* Handle any new events occurred while waiting. */ - if (process_event ()) - { - result = 1; - break; - } + int result = 0; - /* If gdb_wait_for_event has returned 1, it means that one - event has been handled. We break out of the loop. */ - if (result) - break; - } /* end of if !set_top_level */ - else + TRY + { + result = gdb_do_one_event (); + } + CATCH (ex, RETURN_MASK_ALL) { - /* 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); + exception_print (gdb_stderr, ex); + + /* If any exception escaped to here, we better enable + stdin. Otherwise, any command that calls async_disable_stdin, + and then throws, will leave stdin inoperable. */ + async_enable_stdin (); + /* 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. */ + current_ui->prompt_state = PROMPT_NEEDED; + observer_notify_command_error (); + /* 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. */ + whether display the prompt or not. */ } + END_CATCH + + if (result < 0) + break; } - return result; -} - -/* Start up the event loop. This is the entry point to the event loop - from the command loop. */ -void -start_event_loop () -{ - /* Loop until there is something to do. This is the entry point to - the event loop engine. gdb_do_one_event will process one event - for each invocation. It always returns 1, unless there are no - more event sources registered. In this case it returns 0. */ - while (gdb_do_one_event () != 0) - ; - - /* We are done with the event loop. There are no more event sources - to listen to. So we exit GDB. */ + /* 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. */ + vs. select. */ void -add_file_handler (fd, proc, client_data) - int fd; - file_handler_func *proc; - gdb_client_data client_data; +add_file_handler (int fd, handler_func * proc, gdb_client_data client_data) { #ifdef HAVE_POLL - create_file_handler (fd, POLLIN, (file_handler_func *) proc, client_data); + 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 - create_file_handler (fd, GDB_READABLE, (file_handler_func *) proc, client_data); + 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. */ + 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 (fd, mask, proc, client_data) - int fd; - int mask; - file_handler_func *proc; - gdb_client_data client_data; +create_file_handler (int fd, int mask, handler_func * proc, + gdb_client_data client_data) { file_handler *file_ptr; -#ifndef HAVE_POLL - int index, bit; -#endif - - /* Do we already have a file handler for this file? (We may be - changing its associated procedure). */ + /* 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) { @@ -360,74 +476,101 @@ create_file_handler (fd, mask, proc, client_data) break; } - /* It is a new file descriptor. */ + /* 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 = XNEW (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 = + XNEW (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; +} -#ifdef HAVE_POLL - - gdb_notifier.num_fds++; - if (gdb_notifier.poll_fds) - gdb_notifier.poll_fds = - (struct pollfd *) realloc (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 /* ! HAVE_POLL */ - - index = fd / (NBBY * sizeof (fd_mask)); - bit = 1 << (fd % (NBBY * sizeof (fd_mask))); +/* Return the next file handler to handle, and advance to the next + file handler, wrapping around if the end of the list is + reached. */ - if (mask & GDB_READABLE) - gdb_notifier.check_masks[index] |= bit; - else - gdb_notifier.check_masks[index] &= ~bit; +static file_handler * +get_next_file_handler_to_handle_and_advance (void) +{ + file_handler *curr_next; - if (mask & GDB_WRITABLE) - (gdb_notifier.check_masks + MASK_SIZE)[index] |= bit; - else - (gdb_notifier.check_masks + MASK_SIZE)[index] &= ~bit; + /* The first time around, this is still NULL. */ + if (gdb_notifier.next_file_handler == NULL) + gdb_notifier.next_file_handler = gdb_notifier.first_file_handler; - if (mask & GDB_EXCEPTION) - (gdb_notifier.check_masks + 2 * (MASK_SIZE))[index] |= bit; - else - (gdb_notifier.check_masks + 2 * (MASK_SIZE))[index] &= ~bit; + curr_next = gdb_notifier.next_file_handler; + gdb_assert (curr_next != NULL); - if (gdb_notifier.num_fds <= fd) - gdb_notifier.num_fds = fd + 1; + /* Advance. */ + gdb_notifier.next_file_handler = curr_next->next_file; + /* Wrap around, if necessary. */ + if (gdb_notifier.next_file_handler == NULL) + gdb_notifier.next_file_handler = gdb_notifier.first_file_handler; -#endif /* HAVE_POLL */ + return curr_next; } /* Remove the file descriptor FD from the list of monitored fd's: - i.e. we don't care anymore about events on the FD. */ + i.e. we don't care anymore about events on the FD. */ void -delete_file_handler (fd) - int fd; +delete_file_handler (int fd) { file_handler *file_ptr, *prev_ptr = NULL; - int i, j; + int i; +#ifdef HAVE_POLL + int j; struct pollfd *new_poll_fds; -#ifndef HAVE_POLL - int index, bit; - unsigned long flags; #endif - /* Find the entry for the given file. */ + /* Find the entry for the given file. */ for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; file_ptr = file_ptr->next_file) @@ -439,68 +582,76 @@ delete_file_handler (fd) if (file_ptr == NULL) return; - /* Deactivate the file descriptor, by clearing its mask, - so that it will not fire again. */ - - file_ptr->mask = 0; - + 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. */ + /* 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)); + 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) + for (i = 0, j = 0; i < gdb_notifier.num_fds; i++) { - (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++; + 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 */ } - free (gdb_notifier.poll_fds); - gdb_notifier.poll_fds = new_poll_fds; - gdb_notifier.num_fds--; - -#else /* ! HAVE_POLL */ - - index = fd / (NBBY * sizeof (fd_mask)); - bit = 1 << (fd % (NBBY * sizeof (fd_mask))); - - if (file_ptr->mask & GDB_READABLE) - gdb_notifier.check_masks[index] &= ~bit; - if (file_ptr->mask & GDB_WRITABLE) - (gdb_notifier.check_masks + MASK_SIZE)[index] &= ~bit; - if (file_ptr->mask & GDB_EXCEPTION) - (gdb_notifier.check_masks + 2 * (MASK_SIZE))[index] &= ~bit; + 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. */ + /* Find current max fd. */ - if ((fd + 1) == gdb_notifier.num_fds) - { - for (gdb_notifier.num_fds = 0; index >= 0; index--) + if ((fd + 1) == gdb_notifier.num_fds) { - flags = gdb_notifier.check_masks[index] - | (gdb_notifier.check_masks + MASK_SIZE)[index] - | (gdb_notifier.check_masks + 2 * (MASK_SIZE))[index]; - if (flags) + gdb_notifier.num_fds--; + for (i = gdb_notifier.num_fds; i; i--) { - for (i = (NBBY * sizeof (fd_mask)); i > 0; i--) - { - if (flags & (((unsigned long) 1) << (i - 1))) - break; - } - gdb_notifier.num_fds = index * (NBBY * sizeof (fd_mask)) + i; - break; + 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; } } -#endif /* HAVE_POLL */ - /* Get rid of the file handler in the file handler list. */ + /* Deactivate the file descriptor, by clearing its mask, + so that it will not fire again. */ + + file_ptr->mask = 0; + + /* If this file handler was going to be the next one to be handled, + advance to the next's next, if any. */ + if (gdb_notifier.next_file_handler == file_ptr) + { + if (file_ptr->next_file == NULL + && file_ptr == gdb_notifier.first_file_handler) + gdb_notifier.next_file_handler = NULL; + else + get_next_file_handler_to_handle_and_advance (); + } + + /* 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 @@ -511,110 +662,189 @@ delete_file_handler (fd) ; prev_ptr->next_file = file_ptr->next_file; } - free ((char *) file_ptr); + 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. */ + corresponding file handler. */ + static void -handle_file_event (event_file_desc) - int event_file_desc; +handle_file_event (file_handler *file_ptr, int ready_mask) { - file_handler *file_ptr; - int mask, error_mask; + int mask; +#ifdef HAVE_POLL + int error_mask; +#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. */ + 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). */ + 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); + /* POLLHUP means EOF, but can be combined with POLLIN to + signal more data to read. */ + error_mask = POLLHUP | POLLERR | POLLNVAL; + mask = ready_mask & (file_ptr->mask | error_mask); -#else /* ! HAVE_POLL */ - mask = file_ptr->ready_mask & file_ptr->mask; + if ((mask & (POLLERR | POLLNVAL)) != 0) + { + /* Work in progress. We may need to tell somebody + what kind of error we had. */ + if (mask & POLLERR) + printf_unfiltered (_("Error detected on fd %d\n"), + file_ptr->fd); + if (mask & 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 (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 = 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 there was a match, then call the handler. */ if (mask != 0) - (*file_ptr->proc) (file_ptr->client_data, mask); - break; + (*file_ptr->proc) (file_ptr->error, file_ptr->client_data); } } } -/* 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. */ +/* 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 () +gdb_wait_for_event (int block) { file_handler *file_ptr; - gdb_event *file_event_ptr; int num_found = 0; - int i; -#ifndef HAVE_POLL - int mask, bit, index; -#endif + /* 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 (block) + update_wait_timeout (); + + if (use_poll) + { #ifdef HAVE_POLL - num_found = - poll (gdb_notifier.poll_fds, (unsigned long) gdb_notifier.num_fds, -1); - -#else /* ! HAVE_POLL */ - memcpy (gdb_notifier.ready_masks, - gdb_notifier.check_masks, - 3 * MASK_SIZE * sizeof (fd_mask)); - num_found = select (gdb_notifier.num_fds, - (SELECT_MASK *) & gdb_notifier.ready_masks[0], - (SELECT_MASK *) & gdb_notifier.ready_masks[MASK_SIZE], - (SELECT_MASK *) & gdb_notifier.ready_masks[2 * MASK_SIZE], - NULL); - - /* Clear the masks after an error from select. */ - if (num_found == -1) - memset (gdb_notifier.ready_masks, - 0, 3 * MASK_SIZE * sizeof (fd_mask)); + int timeout; + + if (block) + timeout = gdb_notifier.timeout_valid ? gdb_notifier.poll_timeout : -1; + else + timeout = 0; + + num_found = poll (gdb_notifier.poll_fds, + (unsigned long) gdb_notifier.num_fds, timeout); + /* 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 + { + struct timeval select_timeout; + struct timeval *timeout_p; - /* Enqueue all detected file events. */ + if (block) + timeout_p = gdb_notifier.timeout_valid + ? &gdb_notifier.select_timeout : NULL; + else + { + memset (&select_timeout, 0, sizeof (select_timeout)); + timeout_p = &select_timeout; + } -#ifdef HAVE_POLL + 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 = gdb_select (gdb_notifier.num_fds, + &gdb_notifier.ready_masks[0], + &gdb_notifier.ready_masks[1], + &gdb_notifier.ready_masks[2], + timeout_p); + + /* 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 if we got a signal, let gdb handle + it. */ + if (errno != EINTR) + perror_with_name (("select")); + } + } + + /* Avoid looking at poll_fds[i]->revents if no event fired. */ + if (num_found <= 0) + return 0; - for (i = 0; (i < gdb_notifier.num_fds) && (num_found > 0); i++) + /* 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. */ + + /* To level the fairness across event descriptors, we handle them in + a round-robin-like fashion. The number and order of descriptors + may change between invocations, but this is good enough. */ + if (use_poll) { - if ((gdb_notifier.poll_fds + i)->revents) - num_found--; - else - continue; +#ifdef HAVE_POLL + int i; + int mask; + + while (1) + { + if (gdb_notifier.next_poll_fds_index >= gdb_notifier.num_fds) + gdb_notifier.next_poll_fds_index = 0; + i = gdb_notifier.next_poll_fds_index++; + + gdb_assert (i < gdb_notifier.num_fds); + if ((gdb_notifier.poll_fds + i)->revents) + break; + } for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; @@ -623,79 +853,54 @@ gdb_wait_for_event () if (file_ptr->fd == (gdb_notifier.poll_fds + i)->fd) break; } + gdb_assert (file_ptr != NULL); - 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 = - (gdb_event *) xmalloc (sizeof (gdb_event)); - file_event_ptr->proc = handle_file_event; - file_event_ptr->fd = file_ptr->fd; - async_queue_event (file_event_ptr, TAIL); - } - } - - file_ptr->ready_mask = (gdb_notifier.poll_fds + i)->revents; + mask = (gdb_notifier.poll_fds + i)->revents; + handle_file_event (file_ptr, mask); + return 1; +#else + internal_error (__FILE__, __LINE__, + _("use_poll without HAVE_POLL")); +#endif /* HAVE_POLL */ } - -#else /* ! HAVE_POLL */ - for (file_ptr = gdb_notifier.first_file_handler; - (file_ptr != NULL) && (num_found > 0); - file_ptr = file_ptr->next_file) + else { - index = file_ptr->fd / (NBBY * sizeof (fd_mask)); - bit = 1 << (file_ptr->fd % (NBBY * sizeof (fd_mask))); - mask = 0; - - if (gdb_notifier.ready_masks[index] & bit) - mask |= GDB_READABLE; - if ((gdb_notifier.ready_masks + MASK_SIZE)[index] & bit) - mask |= GDB_WRITABLE; - if ((gdb_notifier.ready_masks + 2 * (MASK_SIZE))[index] & bit) - mask |= GDB_EXCEPTION; - - if (!mask) - continue; - else - num_found--; + /* See comment about even source fairness above. */ + int mask = 0; - /* Enqueue an event only if this is still a new event for - this fd. */ - - if (file_ptr->ready_mask == 0) + do { - file_event_ptr = - (gdb_event *) xmalloc (sizeof (gdb_event)); - file_event_ptr->proc = handle_file_event; - file_event_ptr->fd = file_ptr->fd; - async_queue_event (file_event_ptr, TAIL); + file_ptr = get_next_file_handler_to_handle_and_advance (); + + 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; } - file_ptr->ready_mask = mask; - } -#endif /* HAVE_POLL */ + while (mask == 0); + handle_file_event (file_ptr, mask); + return 1; + } return 0; } -/* Create an asynchronous handler, allocating memory for it. +/* 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. */ + whenever the handler is invoked. */ async_signal_handler * -create_async_signal_handler (proc, client_data) - async_handler_func *proc; - gdb_client_data client_data; +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 = XNEW (async_signal_handler); async_handler_ptr->ready = 0; async_handler_ptr->next_handler = NULL; async_handler_ptr->proc = proc; @@ -708,29 +913,48 @@ create_async_signal_handler (proc, client_data) 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. */ +/* 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_handler_ptr) - async_signal_handler *async_handler_ptr; +mark_async_signal_handler (async_signal_handler * async_handler_ptr) { - ((async_signal_handler *) async_handler_ptr)->ready = 1; - async_handler_ready = 1; + async_handler_ptr->ready = 1; + serial_event_set (async_signal_handlers_serial_event); } -/* Call all the handlers that are ready. */ -static void -invoke_async_signal_handler () +/* See event-loop.h. */ + +void +clear_async_signal_handler (async_signal_handler *async_handler_ptr) +{ + async_handler_ptr->ready = 0; +} + +/* See event-loop.h. */ + +int +async_signal_handler_is_marked (async_signal_handler *async_handler_ptr) +{ + return async_handler_ptr->ready; +} + +/* Call all the handlers that are ready. Returns true if any was + indeed ready. */ + +static int +invoke_async_signal_handlers (void) { async_signal_handler *async_handler_ptr; + int any_ready = 0; - if (async_handler_ready == 0) - return; - async_handler_ready = 0; + /* We're going to handle all pending signals, so no need to wake up + the event loop again the next time around. Note this must be + cleared _before_ calling the callbacks, to avoid races. */ + serial_event_clear (async_signal_handlers_serial_event); - /* Invoke ready handlers. */ + /* Invoke all ready handlers. */ while (1) { @@ -743,18 +967,21 @@ invoke_async_signal_handler () } if (async_handler_ptr == NULL) break; + any_ready = 1; async_handler_ptr->ready = 0; + /* Async signal handlers have no connection to whichever was the + current UI, and thus always run on the main one. */ + current_ui = main_ui; (*async_handler_ptr->proc) (async_handler_ptr->client_data); } - return; + return any_ready; } -/* Delete an asynchronous handler (ASYNC_HANDLER_PTR). +/* Delete an asynchronous handler (ASYNC_HANDLER_PTR). Free the space allocated for it. */ void -delete_async_signal_handler (async_handler_ptr) - async_signal_handler **async_handler_ptr; +delete_async_signal_handler (async_signal_handler ** async_handler_ptr) { async_signal_handler *prev_ptr; @@ -767,19 +994,289 @@ delete_async_signal_handler (async_handler_ptr) else { prev_ptr = sighandler_list.first_handler; - while (prev_ptr->next_handler != (*async_handler_ptr) && prev_ptr) + while (prev_ptr && prev_ptr->next_handler != (*async_handler_ptr)) prev_ptr = prev_ptr->next_handler; + gdb_assert (prev_ptr); prev_ptr->next_handler = (*async_handler_ptr)->next_handler; if (sighandler_list.last_handler == (*async_handler_ptr)) sighandler_list.last_handler = prev_ptr; } - free ((char *) (*async_handler_ptr)); + xfree ((*async_handler_ptr)); (*async_handler_ptr) = NULL; } -/* Is it necessary to call invoke_async_signal_handler? */ +/* Create an asynchronous event handler, allocating memory for it. + Return a pointer to the newly created handler. PROC is the + function to call with CLIENT_DATA argument whenever the handler is + invoked. */ +async_event_handler * +create_async_event_handler (async_event_handler_func *proc, + gdb_client_data client_data) +{ + async_event_handler *h; + + h = XNEW (struct async_event_handler); + h->ready = 0; + h->next_handler = NULL; + h->proc = proc; + h->client_data = client_data; + if (async_event_handler_list.first_handler == NULL) + async_event_handler_list.first_handler = h; + else + async_event_handler_list.last_handler->next_handler = h; + async_event_handler_list.last_handler = h; + return h; +} + +/* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information + will be used by gdb_do_one_event. The caller will be whoever + created the event source, and wants to signal that the event is + ready to be handled. */ +void +mark_async_event_handler (async_event_handler *async_handler_ptr) +{ + async_handler_ptr->ready = 1; +} + +/* See event-loop.h. */ + +void +clear_async_event_handler (async_event_handler *async_handler_ptr) +{ + async_handler_ptr->ready = 0; +} + +/* Check if asynchronous event handlers are ready, and call the + handler function for one that is. */ + +static int +check_async_event_handlers (void) +{ + async_event_handler *async_handler_ptr; + + for (async_handler_ptr = async_event_handler_list.first_handler; + async_handler_ptr != NULL; + async_handler_ptr = async_handler_ptr->next_handler) + { + if (async_handler_ptr->ready) + { + async_handler_ptr->ready = 0; + (*async_handler_ptr->proc) (async_handler_ptr->client_data); + return 1; + } + } + + return 0; +} + +/* Delete an asynchronous handler (ASYNC_HANDLER_PTR). + Free the space allocated for it. */ +void +delete_async_event_handler (async_event_handler **async_handler_ptr) +{ + async_event_handler *prev_ptr; + + if (async_event_handler_list.first_handler == *async_handler_ptr) + { + async_event_handler_list.first_handler + = (*async_handler_ptr)->next_handler; + if (async_event_handler_list.first_handler == NULL) + async_event_handler_list.last_handler = NULL; + } + else + { + prev_ptr = async_event_handler_list.first_handler; + while (prev_ptr && prev_ptr->next_handler != *async_handler_ptr) + prev_ptr = prev_ptr->next_handler; + gdb_assert (prev_ptr); + prev_ptr->next_handler = (*async_handler_ptr)->next_handler; + if (async_event_handler_list.last_handler == (*async_handler_ptr)) + async_event_handler_list.last_handler = prev_ptr; + } + xfree (*async_handler_ptr); + *async_handler_ptr = NULL; +} + +/* Create a timer that will expire in MS milliseconds from now. When + the timer is ready, PROC will be executed. At creation, the timer + is added 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 ms, timer_handler_func *proc, + gdb_client_data client_data) +{ + using namespace std::chrono; + struct gdb_timer *timer_ptr, *timer_index, *prev_timer; + + steady_clock::time_point time_now = steady_clock::now (); + + timer_ptr = new gdb_timer (); + timer_ptr->when = time_now + milliseconds (ms); + 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 (timer_index->when > timer_ptr->when) + 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; + } + delete timer_ptr; + + gdb_notifier.timeout_valid = 0; +} + +/* Convert a std::chrono duration to a struct timeval. */ + +template +static struct timeval +duration_cast_timeval (const Duration &d) +{ + using namespace std::chrono; + seconds sec = duration_cast (d); + microseconds msec = duration_cast (d - sec); + + struct timeval tv; + tv.tv_sec = sec.count (); + tv.tv_usec = msec.count (); + return tv; +} + +/* Update the timeout for the select() or poll(). Returns true if the + timer has already expired, false otherwise. */ + +static int +update_wait_timeout (void) +{ + if (timer_list.first_timer != NULL) + { + using namespace std::chrono; + steady_clock::time_point time_now = steady_clock::now (); + struct timeval timeout; + + if (timer_list.first_timer->when < time_now) + { + /* It expired already. */ + timeout.tv_sec = 0; + timeout.tv_usec = 0; + } + else + { + steady_clock::duration d = timer_list.first_timer->when - time_now; + timeout = duration_cast_timeval (d); + } + + /* Update the timeout for select/ poll. */ + if (use_poll) + { +#ifdef HAVE_POLL + gdb_notifier.poll_timeout = timeout.tv_sec * 1000; +#else + internal_error (__FILE__, __LINE__, + _("use_poll without HAVE_POLL")); +#endif /* HAVE_POLL */ + } + else + { + gdb_notifier.select_timeout.tv_sec = timeout.tv_sec; + gdb_notifier.select_timeout.tv_usec = timeout.tv_usec; + } + gdb_notifier.timeout_valid = 1; + + if (timer_list.first_timer->when < time_now) + 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 -check_async_ready () +poll_timers (void) { - return async_handler_ready; + 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. */ + delete timer_ptr; + + /* Call the procedure associated with that timer. */ + (proc) (client_data); + + return 1; + } + + return 0; }