X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fevent-loop.h;h=155dafad9184bae9667a946babac3c870dad31e1;hb=5fe966540d6b748f825774868463003700f0c878;hp=02c3fe308992244d23740bb9cd93867156d602c9;hpb=2acceee2182a942e6a79a972009540990f4dfabf;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/event-loop.h b/gdb/event-loop.h index 02c3fe3089..155dafad91 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) 1999-2016 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, @@ -15,32 +15,42 @@ 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 +/* 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 @@ -53,43 +63,85 @@ 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. + infinite loop. - Corollary tasks are the creation and deletion of event sources. */ + Corollary tasks are the creation and deletion of event sources. */ -typedef PTR gdb_client_data; +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); -/* 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) - /* Exported functions from event-loop.c */ 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 void mark_async_signal_handler (struct async_signal_handler *async_handler_ptr); +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 **async_handler_ptr); -extern int create_timer (int milliseconds, timer_handler_func * proc, gdb_client_data client_data); + 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); + +/* Call the handler from HANDLER immediately. This function + runs signal handlers when returning to the event loop would be too + slow. Do not call this directly; use gdb_call_async_signal_handler, + below, with IMMEDIATE_P == 1. */ +void call_async_signal_handler (struct async_signal_handler *handler); + +/* Call the handler from HANDLER the next time through the event loop. + Do not call this directly; use gdb_call_async_signal_handler, + below, with IMMEDIATE_P == 0. */ +void mark_async_signal_handler (struct async_signal_handler *handler); + +/* Returns true if HANDLER is marked ready. */ + +extern int + async_signal_handler_is_marked (struct async_signal_handler *handler); + +/* Mark HANDLER as NOT ready. */ + +extern void clear_async_signal_handler (struct async_signal_handler *handler); + +/* Wrapper for the body of signal handlers. Call this function from + any SIGINT handler which needs to access GDB data structures or + escape via longjmp. If IMMEDIATE_P is set, this triggers either + immediately (for POSIX platforms), or from gdb_select (for + MinGW). If IMMEDIATE_P is clear, the handler will run the next + time we return to the event loop and any current select calls + will be interrupted. */ + +void gdb_call_async_signal_handler (struct async_signal_handler *handler, + int immediate_p); + +/* 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); + +/* 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); + +/* Call the handler from HANDLER the next time through the event + loop. */ +extern void mark_async_event_handler (struct async_event_handler *handler); + +/* Mark the handler (ASYNC_HANDLER_PTR) as NOT ready. */ + +extern void clear_async_event_handler (struct async_event_handler *handler); + +extern void initialize_async_signal_handlers (void);