From: Pedro Alves Date: Tue, 12 Apr 2016 15:49:32 +0000 (+0100) Subject: Eliminate immediate_quit X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=585a46a2d01d25181926329f258f1d1374f93e99;p=binutils-gdb.git Eliminate immediate_quit This finally gets rid of immediate_quit (and surrounding infrustruture), as nothing sets it anymore. gdb_call_async_signal_handler was only necessary in order to handle immediate_quit. We can just call mark_async_signal_handler directly on all hosts now. In turn, we can clean up mingw-hdep.c's gdb_select a bit, as sigint_event / sigint_handler is no longer needed. gdb/ChangeLog: 2016-04-12 Pedro Alves * defs.h: Update comments on SIGINT handling. (immediate_quit): Delete declaration. * event-loop.c (call_async_signal_handler): Delete. * event-loop.h (call_async_signal_handler): Delete declaration. (mark_async_signal_handler): Update comments. (gdb_call_async_signal_handler): Delete declaration. * event-top.c (handle_sigint): Call mark_async_signal_handler instead of gdb_call_async_signal_handler. * exceptions.c (prepare_to_throw_exception): Remove reference to immediate_quit. (exception_fprintf): Remove comments about immediate_quit. * mingw-hdep.c (sigint_event, sigint_handler): Delete. (gdb_select): Don't wait on sigint_event. (gdb_call_async_signal_handler): Delete. (_initialize_mingw_hdep): Delete. * posix-hdep.c (gdb_call_async_signal_handler): Delete. * utils.c (immediate_quit): Delete. --- diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 1f6200fbb03..0e8327eb8d7 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,23 @@ +2016-04-12 Pedro Alves + + * defs.h: Update comments on SIGINT handling. + (immediate_quit): Delete declaration. + * event-loop.c (call_async_signal_handler): Delete. + * event-loop.h (call_async_signal_handler): Delete declaration. + (mark_async_signal_handler): Update comments. + (gdb_call_async_signal_handler): Delete declaration. + * event-top.c (handle_sigint): Call mark_async_signal_handler + instead of gdb_call_async_signal_handler. + * exceptions.c (prepare_to_throw_exception): Remove reference to + immediate_quit. + (exception_fprintf): Remove comments about immediate_quit. + * mingw-hdep.c (sigint_event, sigint_handler): Delete. + (gdb_select): Don't wait on sigint_event. + (gdb_call_async_signal_handler): Delete. + (_initialize_mingw_hdep): Delete. + * posix-hdep.c (gdb_call_async_signal_handler): Delete. + * utils.c (immediate_quit): Delete. + 2016-04-12 Pedro Alves * defs.h (quit_handler_ftype, quit_handler) diff --git a/gdb/defs.h b/gdb/defs.h index 83e4e11c02a..482ef1cb361 100644 --- a/gdb/defs.h +++ b/gdb/defs.h @@ -125,11 +125,10 @@ extern char *python_libdir; /* * Search path for separate debug files. */ extern char *debug_file_directory; -/* GDB has two methods for handling SIGINT. When immediate_quit is - nonzero, a SIGINT results in an immediate longjmp out of the signal - handler. Otherwise, SIGINT simply sets a flag; code that might - take a long time, and which ought to be interruptible, checks this - flag using the QUIT macro. +/* GDB's SIGINT handler basically sets a flag; code that might take a + long time before it gets back to the event loop, and which ought to + be interruptible, checks this flag using the QUIT macro, which, if + GDB has the terminal, throws a quit exception. In addition to setting a flag, the SIGINT handler also marks a select/poll-able file descriptor as read-ready. That is used by @@ -176,8 +175,6 @@ extern void default_quit_handler (void); /* Flag that function quit should call quit_force. */ extern volatile int sync_quit_force_run; -extern int immediate_quit; - extern void quit (void); /* Helper for the QUIT macro. */ diff --git a/gdb/event-loop.c b/gdb/event-loop.c index 052d5351f9a..60ef2a5d96e 100644 --- a/gdb/event-loop.c +++ b/gdb/event-loop.c @@ -911,15 +911,6 @@ create_async_signal_handler (sig_handler_func * proc, return async_handler_ptr; } -/* Call the handler from HANDLER immediately. This function runs - signal handlers when returning to the event loop would be too - slow. */ -void -call_async_signal_handler (struct async_signal_handler *handler) -{ - (*handler->proc) (handler->client_data); -} - /* 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 diff --git a/gdb/event-loop.h b/gdb/event-loop.h index 155dafad918..7159d975252 100644 --- a/gdb/event-loop.h +++ b/gdb/event-loop.h @@ -91,16 +91,9 @@ extern int create_timer (int milliseconds, 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); +/* 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. */ @@ -111,17 +104,6 @@ extern int 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 diff --git a/gdb/event-top.c b/gdb/event-top.c index 41d3aacead4..fc1a6c60753 100644 --- a/gdb/event-top.c +++ b/gdb/event-top.c @@ -901,18 +901,11 @@ handle_sigint (int sig) it may be quite a while before we get back to the event loop. So set quit_flag to 1 here. Then if QUIT is called before we get to the event loop, we will unwind as expected. */ - set_quit_flag (); - /* If immediate_quit is set, we go ahead and process the SIGINT right - away, even if we usually would defer this to the event loop. The - assumption here is that it is safe to process ^C immediately if - immediate_quit is set. If we didn't, SIGINT would be really - processed only the next time through the event loop. To get to - that point, though, the command that we want to interrupt needs to - finish first, which is unacceptable. If immediate quit is not set, - we process SIGINT the next time through the loop, which is fine. */ - gdb_call_async_signal_handler (sigint_token, immediate_quit); + /* In case nothing calls QUIT before the event loop is reached, the + event loop handles it. */ + mark_async_signal_handler (sigint_token); } /* See gdb_select.h. */ diff --git a/gdb/exceptions.c b/gdb/exceptions.c index ffdd1f37e0f..7f6599ffaf5 100644 --- a/gdb/exceptions.c +++ b/gdb/exceptions.c @@ -30,7 +30,6 @@ void prepare_to_throw_exception (void) { - immediate_quit = 0; } static void @@ -148,12 +147,7 @@ exception_fprintf (struct ui_file *file, struct gdb_exception e, returned by catch_exceptions(). It is an internal_error() for FUNC() to return a negative value. - See exceptions.h for further usage details. - - Must not be called with immediate_quit in effect (bad things might - happen, say we got a signal in the middle of a memcpy to quit_return). - This is an OK restriction; with very few exceptions immediate_quit can - be replaced by judicious use of QUIT. */ + See exceptions.h for further usage details. */ /* MAYBE: cagney/1999-11-05: catch_errors() in conjunction with error() et al. could maintain a set of flags that indicate the diff --git a/gdb/mingw-hdep.c b/gdb/mingw-hdep.c index 8247a8cd7d8..2e010fa5d65 100644 --- a/gdb/mingw-hdep.c +++ b/gdb/mingw-hdep.c @@ -27,14 +27,6 @@ #include -/* This event is signalled whenever an asynchronous SIGINT handler - needs to perform an action in the main thread. */ -static HANDLE sigint_event; - -/* When SIGINT_EVENT is signalled, gdb_select will call this - function. */ -struct async_signal_handler *sigint_handler; - /* Return an absolute file name of the running GDB, if possible, or ARGV0 if not. The return value is in malloc'ed storage. */ @@ -120,8 +112,7 @@ gdb_select (int n, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, } } - gdb_assert (num_handles < MAXIMUM_WAIT_OBJECTS); - handles[num_handles++] = sigint_event; + gdb_assert (num_handles <= MAXIMUM_WAIT_OBJECTS); event = WaitForMultipleObjects (num_handles, handles, @@ -184,46 +175,5 @@ gdb_select (int n, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, while (RL_ISSTATE (RL_STATE_SIGHANDLER)) Sleep (1); - if (h == sigint_event - || WaitForSingleObject (sigint_event, 0) == WAIT_OBJECT_0) - { - if (sigint_handler != NULL) - call_async_signal_handler (sigint_handler); - - if (num_ready == 0) - { - errno = EINTR; - return -1; - } - } - return num_ready; } - -/* Wrapper for the body of signal handlers. On Windows systems, a - SIGINT handler runs in its own thread. We can't longjmp from - there, and we shouldn't even prompt the user. Delay HANDLER - until the main thread is next in gdb_select. */ - -void -gdb_call_async_signal_handler (struct async_signal_handler *handler, - int immediate_p) -{ - if (immediate_p) - sigint_handler = handler; - else - { - mark_async_signal_handler (handler); - sigint_handler = NULL; - } - SetEvent (sigint_event); -} - -/* -Wmissing-prototypes */ -extern initialize_file_ftype _initialize_mingw_hdep; - -void -_initialize_mingw_hdep (void) -{ - sigint_event = CreateEvent (0, FALSE, FALSE, 0); -} diff --git a/gdb/posix-hdep.c b/gdb/posix-hdep.c index 90cab8f5b3c..e9db5761048 100644 --- a/gdb/posix-hdep.c +++ b/gdb/posix-hdep.c @@ -30,16 +30,3 @@ gdb_select (int n, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, { return select (n, readfds, writefds, exceptfds, timeout); } - -/* Wrapper for the body of signal handlers. Nothing special needed on - POSIX platforms. */ - -void -gdb_call_async_signal_handler (struct async_signal_handler *handler, - int immediate_p) -{ - if (immediate_p) - call_async_signal_handler (handler); - else - mark_async_signal_handler (handler); -} diff --git a/gdb/utils.c b/gdb/utils.c index bc62218a7b2..db5104d025a 100644 --- a/gdb/utils.c +++ b/gdb/utils.c @@ -109,19 +109,6 @@ static int debug_timestamp = 0; int job_control; -/* Nonzero means quit immediately if Control-C is typed now, rather - than waiting until QUIT is executed. Be careful in setting this; - code which executes with immediate_quit set has to be very careful - about being able to deal with being interrupted at any time. It is - almost always better to use QUIT; the only exception I can think of - is being able to quit out of a system call (using EINTR loses if - the SIGINT happens between the previous QUIT and the system call). - To immediately quit in the case in which a SIGINT happens between - the previous QUIT and setting immediate_quit (desirable anytime we - expect to block), call QUIT after setting immediate_quit. */ - -int immediate_quit; - /* Nonzero means that strings with character values >0x7F should be printed as octal escapes. Zero means just print the value (e.g. it's an international character, and the terminal or window can cope.) */