X-Git-Url: http://git.hcoop.net/bpt/guile.git/blobdiff_plain/34d19ef64368a8bac8a32f799b71dc05dd587654..eb7e1603ad497d0efff686e26e23af987c567721:/libguile/scmsigs.c diff --git a/libguile/scmsigs.c b/libguile/scmsigs.c index 95e15ec4d..a4a21c53f 100644 --- a/libguile/scmsigs.c +++ b/libguile/scmsigs.c @@ -1,47 +1,27 @@ -/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001 Free Software Foundation, Inc. +/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002 Free Software Foundation, Inc. * - * 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, or (at your option) - * any later version. + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. * - * This program is distributed in the hope that it will be useful, + * This library 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. + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. * - * You should have received a copy of the GNU General Public License - * along with this software; see the file COPYING. If not, write to - * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, - * Boston, MA 02111-1307 USA - * - * As a special exception, the Free Software Foundation gives permission - * for additional uses of the text contained in its release of GUILE. - * - * The exception is that, if you link the GUILE library with other files - * to produce an executable, this does not by itself cause the - * resulting executable to be covered by the GNU General Public License. - * Your use of that executable is in no way restricted on account of - * linking the GUILE library code into it. - * - * This exception does not however invalidate any other reasons why - * the executable file might be covered by the GNU General Public License. - * - * This exception applies only to the code released by the - * Free Software Foundation under the name GUILE. If you copy - * code from other Free Software Foundation releases into a copy of - * GUILE, as the General Public License permits, the exception does - * not apply to the code that you add in this way. To avoid misleading - * anyone as to the status of such modified files, you must delete - * this exception notice from them. - * - * If you write modifications of your own for GUILE, it is your choice - * whether to permit this exception to apply to your modifications. - * If you do not wish that, delete this exception notice. */ + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#if HAVE_CONFIG_H +# include +#endif + #include #include @@ -63,19 +43,6 @@ #include #endif -/* The thread system has its own sleep and usleep functions. */ -#ifndef USE_THREADS - -#if defined(MISSING_SLEEP_DECL) -int sleep (); -#endif - -#if defined(HAVE_USLEEP) && defined(MISSING_USLEEP_DECL) -int usleep (); -#endif - -#endif - #ifdef __MINGW32__ #include #define alarm(sec) (0) @@ -102,18 +69,22 @@ int usleep (); /* take_signal is installed as the C signal handler whenever a Scheme - handler is set. when a signal arrives, take_signal marks the corresponding - element of got_signal and marks signal_async. the thunk in signal_async - (sys_deliver_signals) will be run at the next opportunity, outside a - critical section. sys_deliver_signals runs each Scheme handler for - which got_signal is set. */ + handler is set. when a signal arrives, take_signal will queue the + Scheme handler procedure for its thread. */ -static SCM signal_async; -static char got_signal[NSIG]; - -/* a Scheme vector of handler procedures. */ +/* Scheme vectors with information about a signal. signal_handlers + contains the handler procedure or #f, signal_handler_cells contains + pre-queued cells for the handler (since we can't do fancy things + during signal delivery), signal_cell_handlers contains the SCM + value to be stuffed into the pre-queued cell upon delivery, and + signal_handler_threads points to the thread that a signal should be + delivered to. +*/ static SCM *signal_handlers; +static SCM signal_handler_cells; +static SCM signal_cell_handlers; +static SCM signal_handler_threads; /* saves the original C handlers, when a new handler is installed. set to SIG_ERR if the original handler is installed. */ @@ -123,55 +94,187 @@ static struct sigaction orig_handlers[NSIG]; static SIGRETTYPE (*orig_handlers[NSIG])(int); #endif + static SIGRETTYPE take_signal (int signum) { - got_signal[signum] = 1; - scm_system_async_mark_from_signal_handler (signal_async); + if (signum >= 0 && signum < NSIG) + { + SCM cell = SCM_VECTOR_REF(signal_handler_cells, signum); + SCM handler = SCM_VECTOR_REF(signal_cell_handlers, signum); + SCM thread = SCM_VECTOR_REF(signal_handler_threads, signum); + scm_root_state *root = scm_i_thread_root (thread); + if (SCM_CONSP (cell)) + { + SCM_SETCAR (cell, handler); + root->pending_asyncs = 1; + } + } + +#ifndef HAVE_SIGACTION + signal (signum, take_signal); +#endif +} + +SCM +scm_sigaction (SCM signum, SCM handler, SCM flags) +{ + return scm_sigaction_for_thread (signum, handler, flags, SCM_UNDEFINED); } static SCM -sys_deliver_signals (void) +close_1 (SCM proc, SCM arg) { - int i; + return scm_primitive_eval_x (scm_list_3 (scm_sym_lambda, SCM_EOL, + scm_list_2 (proc, arg))); +} - for (i = 0; i < NSIG; i++) +/* Make sure that signal SIGNUM can be delivered to THREAD, using + HANDLER. THREAD and HANDLER must either both be non-#f (which + means install the handler), or both #f (which means deinstall an + existing handler). +*/ + +struct install_handler_data { + int signum; + SCM thread; + SCM handler; +}; + +static SCM +scm_delq_spine_x (SCM cell, SCM list) +{ + SCM s = list, prev = SCM_BOOL_F; + + while (!SCM_EQ_P (cell, s)) + { + if (SCM_NULLP (s)) + return list; + prev = s; + s = SCM_CDR (s); + } + if (SCM_FALSEP (prev)) + return SCM_CDR (cell); + else { - if (got_signal[i]) + SCM_SETCDR (prev, SCM_CDR (cell)); + return list; + } +} + +static void * +really_install_handler (void *data) +{ + struct install_handler_data *args = data; + int signum = args->signum; + SCM thread = args->thread; + SCM handler = args->handler; + SCM cell; + SCM old_thread; + + /* The following modifications are done while signals can be + delivered. That is not a real problem since the signal handler + will only touch the car of the handler cell and set the + pending_asyncs trigger of a thread. While the data structures + are in flux, the signal handler might store the wrong handler in + the cell, or set pending_asyncs of the wrong thread. We fix this + at the end by making sure that the cell has the right handler in + it, if any, and that pending_asyncs is set for the new thread. + */ + + /* Make sure we have a cell. */ + cell = SCM_VECTOR_REF (signal_handler_cells, signum); + if (SCM_FALSEP (cell)) + { + cell = scm_cons (SCM_BOOL_F, SCM_EOL); + SCM_VECTOR_SET (signal_handler_cells, signum, cell); + } + + /* Make sure it is queued for the right thread. */ + old_thread = SCM_VECTOR_REF (signal_handler_threads, signum); + if (!SCM_EQ_P (thread, old_thread)) + { + scm_root_state *r; + if (!SCM_FALSEP (old_thread)) { - /* The flag is reset before calling the handler in case the - handler doesn't return. If the handler doesn't return - but leaves other signals flagged, they their handlers - will be applied some time later when the async is checked - again. It would probably be better to reset the flags - after doing a longjmp. */ - got_signal[i] = 0; -#ifndef HAVE_SIGACTION - signal (i, take_signal); -#endif - scm_call_1 (SCM_VELTS (*signal_handlers)[i], SCM_MAKINUM (i)); + r = scm_i_thread_root (old_thread); + r->signal_asyncs = scm_delq_spine_x (cell, r->signal_asyncs); + } + if (!SCM_FALSEP (thread)) + { + r = scm_i_thread_root (thread); + SCM_SETCDR (cell, r->signal_asyncs); + r->signal_asyncs = cell; + /* Set pending_asyncs just in case. A signal that is + delivered while we modify the data structures here might set + pending_asyncs of old_thread. */ + r->pending_asyncs = 1; } + SCM_VECTOR_SET (signal_handler_threads, signum, thread); } - return SCM_UNSPECIFIED; + + /* Set the new handler. */ + if (SCM_FALSEP (handler)) + { + SCM_VECTOR_SET (*signal_handlers, signum, SCM_BOOL_F); + SCM_VECTOR_SET (signal_cell_handlers, signum, SCM_BOOL_F); + } + else + { + SCM_VECTOR_SET (*signal_handlers, signum, handler); + SCM_VECTOR_SET (signal_cell_handlers, signum, + close_1 (handler, scm_int2num (signum))); + } + + /* Now fix up the cell. It might contain the old handler but since + it is now queued for the new thread, we must make sure that the + new handler is run. Any signal that is delivered during the + following code will install the new handler, so we have no + problem. + */ + if (!SCM_FALSEP (SCM_CAR (cell))) + SCM_SETCAR (cell, SCM_VECTOR_REF (signal_cell_handlers, signum)); + + /* Phfew. That should be it. */ + return NULL; +} + +static void +install_handler (int signum, SCM thread, SCM handler) +{ + /* We block asyncs while installing the handler. It would be safe + to leave them on, but we might run the wrong handler should a + signal be delivered. + */ + + struct install_handler_data args; + args.signum = signum; + args.thread = thread; + args.handler = handler; + scm_c_call_with_blocked_asyncs (really_install_handler, &args); } /* user interface for installation of signal handlers. */ -SCM_DEFINE (scm_sigaction, "sigaction", 1, 2, 0, - (SCM signum, SCM handler, SCM flags), +SCM_DEFINE (scm_sigaction_for_thread, "sigaction", 1, 3, 0, + (SCM signum, SCM handler, SCM flags, SCM thread), "Install or report the signal handler for a specified signal.\n\n" "@var{signum} is the signal number, which can be specified using the value\n" "of variables such as @code{SIGINT}.\n\n" - "If @var{action} is omitted, @code{sigaction} returns a pair: the\n" + "If @var{handler} is omitted, @code{sigaction} returns a pair: the\n" "CAR is the current\n" "signal hander, which will be either an integer with the value @code{SIG_DFL}\n" "(default action) or @code{SIG_IGN} (ignore), or the Scheme procedure which\n" "handles the signal, or @code{#f} if a non-Scheme procedure handles the\n" "signal. The CDR contains the current @code{sigaction} flags for the handler.\n\n" - "If @var{action} is provided, it is installed as the new handler for\n" - "@var{signum}. @var{action} can be a Scheme procedure taking one\n" + "If @var{handler} is provided, it is installed as the new handler for\n" + "@var{signum}. @var{handler} can be a Scheme procedure taking one\n" "argument, or the value of @code{SIG_DFL} (default action) or\n" "@code{SIG_IGN} (ignore), or @code{#f} to restore whatever signal handler\n" - "was installed before @code{sigaction} was first used. Flags can\n" + "was installed before @code{sigaction} was first used. When\n" + "a scheme procedure has been specified, that procedure will run\n" + "in the given @var{thread}. When no thread has been given, the\n" + "thread that made this call to @code{sigaction} is used.\n" + "Flags can " "optionally be specified for the new handler (@code{SA_RESTART} will\n" "always be added if it's available and the system is using restartable\n" "system calls.) The return value is a pair with information about the\n" @@ -180,7 +283,7 @@ SCM_DEFINE (scm_sigaction, "sigaction", 1, 2, 0, "facility. Maybe this is not needed, since the thread support may\n" "provide solutions to the problem of consistent access to data\n" "structures.") -#define FUNC_NAME s_scm_sigaction +#define FUNC_NAME s_scm_sigaction_for_thread { int csig; #ifdef HAVE_SIGACTION @@ -196,6 +299,8 @@ SCM_DEFINE (scm_sigaction, "sigaction", 1, 2, 0, SCM old_handler; SCM_VALIDATE_INUM_COPY (1, signum, csig); + if (csig < 0 || csig > NSIG) + SCM_OUT_OF_RANGE (1, signum); #if defined(HAVE_SIGACTION) #if defined(SA_RESTART) && defined(HAVE_RESTARTABLE_SYSCALLS) /* don't allow SA_RESTART to be omitted if HAVE_RESTARTABLE_SYSCALLS @@ -212,8 +317,18 @@ SCM_DEFINE (scm_sigaction, "sigaction", 1, 2, 0, } sigemptyset (&action.sa_mask); #endif + + if (SCM_UNBNDP (thread)) + thread = scm_current_thread (); + else + { + SCM_VALIDATE_THREAD (4, thread); + if (scm_c_thread_exited_p (thread)) + SCM_MISC_ERROR ("thread has already exited", SCM_EOL); + } + SCM_DEFER_INTS; - old_handler = SCM_VELTS(*signal_handlers)[csig]; + old_handler = SCM_VECTOR_REF(*signal_handlers, csig); if (SCM_UNBNDP (handler)) query_only = 1; else if (SCM_EQ_P (scm_integer_p (handler), SCM_BOOL_T)) @@ -226,7 +341,7 @@ SCM_DEFINE (scm_sigaction, "sigaction", 1, 2, 0, #else chandler = (SIGRETTYPE (*) (int)) SCM_INUM (handler); #endif - SCM_VECTOR_SET (*signal_handlers, csig, SCM_BOOL_F); + install_handler (csig, SCM_BOOL_F, SCM_BOOL_F); } else SCM_OUT_OF_RANGE (2, handler); @@ -241,8 +356,7 @@ SCM_DEFINE (scm_sigaction, "sigaction", 1, 2, 0, { action = orig_handlers[csig]; orig_handlers[csig].sa_handler = SIG_ERR; - SCM_VECTOR_SET (*signal_handlers, csig, SCM_BOOL_F); - + install_handler (csig, SCM_BOOL_F, SCM_BOOL_F); } #else if (orig_handlers[csig] == SIG_ERR) @@ -251,7 +365,7 @@ SCM_DEFINE (scm_sigaction, "sigaction", 1, 2, 0, { chandler = orig_handlers[csig]; orig_handlers[csig] = SIG_ERR; - SCM_VECTOR_SET (*signal_handlers, csig, SCM_BOOL_F); + install_handler (csig, SCM_BOOL_F, SCM_BOOL_F); } #endif } @@ -267,7 +381,7 @@ SCM_DEFINE (scm_sigaction, "sigaction", 1, 2, 0, if (orig_handlers[csig] == SIG_ERR) save_handler = 1; #endif - SCM_VECTOR_SET (*signal_handlers, csig, handler); + install_handler (csig, thread, handler); } /* XXX - Silently ignore setting handlers for `program error signals' @@ -496,44 +610,23 @@ SCM_DEFINE (scm_sleep, "sleep", 1, 0, 0, { unsigned long j; SCM_VALIDATE_INUM_MIN (1, i,0); -#ifdef USE_THREADS j = scm_thread_sleep (SCM_INUM(i)); -#else - j = sleep (SCM_INUM(i)); -#endif return scm_ulong2num (j); } #undef FUNC_NAME -#if defined(USE_THREADS) || defined(HAVE_USLEEP) || defined(__MINGW32__) SCM_DEFINE (scm_usleep, "usleep", 1, 0, 0, (SCM i), "Sleep for I microseconds. @code{usleep} is not available on\n" "all platforms.") #define FUNC_NAME s_scm_usleep { + unsigned long j; SCM_VALIDATE_INUM_MIN (1, i,0); - -#ifdef USE_THREADS - /* If we have threads, we use the thread system's sleep function. */ - { - unsigned long j = scm_thread_usleep (SCM_INUM (i)); - return scm_ulong2num (j); - } -#else -#ifdef USLEEP_RETURNS_VOID - usleep (SCM_INUM (i)); - return SCM_INUM0; -#else - { - int j = usleep (SCM_INUM (i)); - return SCM_MAKINUM (j); - } -#endif -#endif + j = scm_thread_usleep (SCM_INUM (i)); + return scm_ulong2num (j); } #undef FUNC_NAME -#endif /* USE_THREADS || HAVE_USLEEP || __MINGW32__ */ SCM_DEFINE (scm_raise, "raise", 1, 0, 0, (SCM sig), @@ -555,20 +648,20 @@ SCM_DEFINE (scm_raise, "raise", 1, 0, 0, void scm_init_scmsigs () { - SCM thunk; int i; signal_handlers = SCM_VARIABLE_LOC (scm_c_define ("signal-handlers", scm_c_make_vector (NSIG, SCM_BOOL_F))); - /* XXX - use scm_c_make_gsubr here instead of `define'? */ - thunk = scm_c_define_gsubr ("%deliver-signals", 0, 0, 0, - sys_deliver_signals); - signal_async = scm_system_async (thunk); + signal_handler_cells = + scm_permanent_object (scm_c_make_vector (NSIG, SCM_BOOL_F)); + signal_cell_handlers = + scm_permanent_object (scm_c_make_vector (NSIG, SCM_BOOL_F)); + signal_handler_threads = + scm_permanent_object (scm_c_make_vector (NSIG, SCM_BOOL_F)); for (i = 0; i < NSIG; i++) { - got_signal[i] = 0; #ifdef HAVE_SIGACTION orig_handlers[i].sa_handler = SIG_ERR;