X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gdb%2Fevent-loop.h;h=99b776618bd42a0431c404de4aae80e1a5a64cad;hb=f81e7e2db6d1aaf47561e54356aee12b585533c2;hp=86abb22f2b734603ce8dd175682fd76b841077ca;hpb=9846de1bb5d61521885ef51fa6b99121ec1be577;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/event-loop.h b/gdb/event-loop.h index 86abb22f2b..99b776618b 100644 --- a/gdb/event-loop.h +++ b/gdb/event-loop.h @@ -1,12 +1,12 @@ /* Definitions used by the GDB event loop. - Copyright 1999 Free Software Foundation, Inc. + Copyright (C) 1999-2019 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, @@ -15,31 +15,45 @@ 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 . */ -/* An event loop listens for events from multiple event sources. When +#ifndef EVENT_LOOP_H +#define EVENT_LOOP_H + +/* An event loop listens for events from multiple event sources. When an event arrives, it is queued and processed by calling the - appropriate event handler. The event loop then continues to listen - for more events. An event loop completes when there are no event + appropriate event handler. The event loop then continues to listen + for more events. An event loop completes when there are no event sources to listen on. External event sources can be plugged into the loop. - There are 3 main components: - - a list of file descriptors to be monitored, GDB_NOTIFIER. - - a list of events that have occurred, EVENT_QUEUE. + There are 4 main components: + - a list of file descriptors to be monitored, GDB_NOTIFIER. + - a list of asynchronous event sources to be monitored, + ASYNC_EVENT_HANDLER_LIST. + - a list of events that have occurred, EVENT_QUEUE. - a list of signal handling functions, SIGHANDLER_LIST. - GDB_NOTIFIER keeps track of the event sources. Event sources for - gdb are currently the UI and the target. Gdb communicates with the - command line user interface via the readline library and usually - communicates with remote targets via a serial port. Serial ports - are represented in GDB as file descriptors and select/poll calls. - For native targets instead, the communication consists of calls to - ptrace and waits (via signals) or calls to poll/select (via file - descriptors). In the current gdb, the code handling events related - to the target resides in the wait_for_inferior function and in - various target specific files (*-tdep.c). + GDB_NOTIFIER keeps track of the file descriptor based event + sources. ASYNC_EVENT_HANDLER_LIST keeps track of asynchronous + event sources that are signalled by some component of gdb, usually + a target_ops instance. Event sources for gdb are currently the UI + and the target. Gdb communicates with the command line user + interface via the readline library and usually communicates with + remote targets via a serial port. Serial ports are represented in + GDB as file descriptors and select/poll calls. For native targets + instead, the communication varies across operating system debug + APIs, but usually consists of calls to ptrace and waits (via + signals) or calls to poll/select (via file descriptors). In the + current gdb, the code handling events related to the target resides + in wait_for_inferior for synchronous targets; or, for asynchronous + capable targets, by having the target register either a target + controlled file descriptor and/or an asynchronous event source in + the event loop, with the fetch_inferior_event function as the event + callback. In both the synchronous and asynchronous cases, usually + the target event is collected through the target_wait interface. + The target is free to install other event sources in the event loop + if it so requires. EVENT_QUEUE keeps track of the events that have happened during the last iteration of the event loop, and need to be processed. An @@ -52,207 +66,69 @@ functions that are invoked through traditional signal handlers. The actions to be taken is response to such events will be executed when the SIGHANDLER_LIST is scanned, the next time through the - infinite loop. - - Corollary tasks are the creation and deletion of event sources. */ - -typedef PTR gdb_client_data; -typedef struct gdb_event gdb_event; - -typedef void (file_handler_func) PARAMS ((gdb_client_data, int mask)); -typedef void (async_handler_func) PARAMS ((gdb_client_data)); -typedef void (event_handler_func) PARAMS ((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 adn 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. */ - file_handler_func *proc; /* Procedure to call when fd is ready. */ - gdb_client_data client_data; /* Argument to pass to proc. */ - 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. */ + infinite loop. -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 */ - async_handler_func *proc; /* Function to call to do the work */ - gdb_client_data client_data; /* Argument to async_handler_func */ - } -async_signal_handler; + Corollary tasks are the creation and deletion of event sources. */ -/* Where to add an event onto the event queue, by queue_event. */ -typedef enum - { - /* Add at tail of queue. It will be processed in first in first - out order. */ - TAIL, - /* Add at head of queue. It will be processed in last in first out - order. */ - HEAD - } -queue_position; - -/* 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) - -/* Type of the mask arguments to select. */ - -#ifndef NO_FD_SET -#define SELECT_MASK fd_set -#else -#ifndef _AIX -typedef long fd_mask; -#endif -#if defined(_IBMR2) -#define SELECT_MASK void -#else -#define SELECT_MASK int -#endif -#endif - -/* Define "NBBY" (number of bits per byte) if it's not already defined. */ - -#ifndef NBBY -#define NBBY 8 -#endif +typedef void *gdb_client_data; +struct async_signal_handler; +struct async_event_handler; +typedef void (handler_func) (int, gdb_client_data); +typedef void (sig_handler_func) (gdb_client_data); +typedef void (async_event_handler_func) (gdb_client_data); +typedef void (timer_handler_func) (gdb_client_data); +/* Exported functions from event-loop.c */ -/* Define the number of fd_masks in an fd_set */ +extern void start_event_loop (void); +extern int gdb_do_one_event (void); +extern void delete_file_handler (int fd); +extern void add_file_handler (int fd, handler_func *proc, + gdb_client_data client_data); +extern struct async_signal_handler * + create_async_signal_handler (sig_handler_func *proc, + gdb_client_data client_data); +extern void delete_async_signal_handler (struct async_signal_handler **); +extern int create_timer (int milliseconds, + timer_handler_func *proc, + gdb_client_data client_data); +extern void delete_timer (int id); -#ifndef FD_SETSIZE -#ifdef OPEN_MAX -#define FD_SETSIZE OPEN_MAX -#else -#define FD_SETSIZE 256 -#endif -#endif -#if !defined(howmany) -#define howmany(x, y) (((x)+((y)-1))/(y)) -#endif -#ifndef NFDBITS -#define NFDBITS NBBY*sizeof(fd_mask) -#endif -#define MASK_SIZE howmany(FD_SETSIZE, NFDBITS) +/* Call the handler from HANDLER the next time through the event + loop. */ +extern void mark_async_signal_handler (struct async_signal_handler *handler); +/* Returns true if HANDLER is marked ready. */ -/* Stack for prompts. Each prompt is composed as a prefix, a prompt - and a suffix. The prompt to be displayed at any given time is the - one on top of the stack. A stack is necessary because of cases in - which the execution of a gdb command requires further input from - the user, like for instance 'commands' for breakpoints and - 'actions' for tracepoints. In these cases, the prompt is '>' and - gdb should process input using the asynchronous readline interface - and the event loop. In order to achieve this, we need to save - somewhere the state of GDB, i.e. that it is processing user input - as part of a command and not as part of the top level command loop. - The prompt stack represents part of the saved state. Another part - would be the function that readline would invoke after a whole line - of input has ben entered. This second piece would be something - like, for instance, where to return within the code for the actions - commands after a line has been read. This latter portion has not - beeen implemented yet. The need for a 3-part prompt arises from - the annotation level. When this is set to 2, the prompt is actually - composed of a prefix, the prompt itself and a suffix. */ +extern int + async_signal_handler_is_marked (struct async_signal_handler *handler); -/* At any particular time there will be always at least one prompt on - the stack, the one being currently displayed by gdb. If gdb is - using annotation level equal 2, there will be 2 prompts on the - stack: the usual one, w/o prefix and suffix (at top - 1), and the - 'composite' one with prefix and suffix added (at top). At this - time, this is the only use of the prompt stack. Resetting annotate - to 0 or 1, pops the top of the stack, resetting its size to one - element. The MAXPROMPTS limit is safe, for now. Once other cases - are dealt with (like the different prompts used for 'commands' or - 'actions') this array implementation of the prompt stack may have - to change. */ +/* Mark HANDLER as NOT ready. */ -#define MAXPROMPTS 10 -struct prompts - { - struct - { - char *prefix; - char *prompt; - char *suffix; - } - prompt_stack[MAXPROMPTS]; - int top; - }; +extern void clear_async_signal_handler (struct async_signal_handler *handler); -#define PROMPT(X) the_prompts.prompt_stack[the_prompts.top + X].prompt -#define PREFIX(X) the_prompts.prompt_stack[the_prompts.top + X].prefix -#define SUFFIX(X) the_prompts.prompt_stack[the_prompts.top + X].suffix +/* Create and register an asynchronous event source in the event loop, + and set PROC as its callback. CLIENT_DATA is passed as argument to + PROC upon its invocation. Returns a pointer to an opaque structure + used to mark as ready and to later delete this event source from + the event loop. */ +extern struct async_event_handler * + create_async_event_handler (async_event_handler_func *proc, + gdb_client_data client_data); -/* Exported functions from event-loop.c */ +/* Remove the event source pointed by HANDLER_PTR created by + CREATE_ASYNC_EVENT_HANDLER from the event loop, and release it. */ +extern void + delete_async_event_handler (struct async_event_handler **handler_ptr); -extern void start_event_loop PARAMS ((void)); -extern void delete_file_handler PARAMS ((int)); -extern void add_file_handler PARAMS ((int, file_handler_func, gdb_client_data)); -extern void mark_async_signal_handler PARAMS ((async_signal_handler *)); -extern async_signal_handler * - create_async_signal_handler PARAMS ((async_handler_func *, gdb_client_data)); -extern void delete_async_signal_handler PARAMS ((async_signal_handler **async_handler_ptr)); +/* Call the handler from HANDLER the next time through the event + loop. */ +extern void mark_async_event_handler (struct async_event_handler *handler); -/* Exported functions from event-top.c. - FIXME: these should really go into top.h. */ +/* Mark the handler (ASYNC_HANDLER_PTR) as NOT ready. */ -extern void display_gdb_prompt PARAMS ((char*)); -extern void async_init_signals PARAMS ((void)); -extern void set_async_editing_command PARAMS ((char *, int, struct cmd_list_element *)); -extern void set_async_annotation_level PARAMS ((char *, int, struct cmd_list_element *)); -extern void set_async_prompt PARAMS ((char *, int, struct cmd_list_element *)); -extern void handle_stop_sig PARAMS ((int)); -extern void handle_sigint PARAMS ((int)); -extern void pop_prompt PARAMS ((void)); -extern void push_prompt PARAMS ((char *, char *, char *)); -extern void gdb_readline2 PARAMS ((void)); +extern void clear_async_event_handler (struct async_event_handler *handler); -/* Exported variables from event-top.c. - FIXME: these should really go into top.h. */ +extern void initialize_async_signal_handlers (void); -extern int async_command_editing_p; -extern char *async_annotation_suffix; -extern char *new_async_prompt; -extern struct prompts the_prompts; -extern void (*call_readline) PARAMS ((void)); -extern void (*input_handler) PARAMS ((char *)); -extern int input_fd; +#endif /* EVENT_LOOP_H */