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-rw-r--r--lib/fatal-signal.c286
1 files changed, 0 insertions, 286 deletions
diff --git a/lib/fatal-signal.c b/lib/fatal-signal.c
deleted file mode 100644
index 8f7cb8ea..00000000
--- a/lib/fatal-signal.c
+++ /dev/null
@@ -1,286 +0,0 @@
-/* Emergency actions in case of a fatal signal.
- Copyright (C) 2003-2004, 2006-2013 Free Software Foundation, Inc.
- Written by Bruno Haible <bruno@clisp.org>, 2003.
-
- 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 3 of the License, or
- (at your option) any later version.
-
- This program 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.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
-
-
-#include <config.h>
-
-/* Specification. */
-#include "fatal-signal.h"
-
-#include <stdbool.h>
-#include <stdlib.h>
-#include <signal.h>
-#include <unistd.h>
-
-#include "sig-handler.h"
-#include "xalloc.h"
-
-#define SIZEOF(a) (sizeof(a) / sizeof(a[0]))
-
-/* ========================================================================= */
-
-
-/* The list of fatal signals.
- These are those signals whose default action is to terminate the process
- without a core dump, except
- SIGKILL - because it cannot be caught,
- SIGALRM SIGUSR1 SIGUSR2 SIGPOLL SIGIO SIGLOST - because applications
- often use them for their own purpose,
- SIGPROF SIGVTALRM - because they are used for profiling,
- SIGSTKFLT - because it is more similar to SIGFPE, SIGSEGV, SIGBUS,
- SIGSYS - because it is more similar to SIGABRT, SIGSEGV,
- SIGPWR - because it of too special use,
- SIGRTMIN...SIGRTMAX - because they are reserved for application use.
- plus
- SIGXCPU, SIGXFSZ - because they are quite similar to SIGTERM. */
-
-static int fatal_signals[] =
- {
- /* ISO C 99 signals. */
-#ifdef SIGINT
- SIGINT,
-#endif
-#ifdef SIGTERM
- SIGTERM,
-#endif
- /* POSIX:2001 signals. */
-#ifdef SIGHUP
- SIGHUP,
-#endif
-#ifdef SIGPIPE
- SIGPIPE,
-#endif
- /* BSD signals. */
-#ifdef SIGXCPU
- SIGXCPU,
-#endif
-#ifdef SIGXFSZ
- SIGXFSZ,
-#endif
- /* Native Windows signals. */
-#ifdef SIGBREAK
- SIGBREAK,
-#endif
- 0
- };
-
-#define num_fatal_signals (SIZEOF (fatal_signals) - 1)
-
-/* Eliminate signals whose signal handler is SIG_IGN. */
-
-static void
-init_fatal_signals (void)
-{
- static bool fatal_signals_initialized = false;
- if (!fatal_signals_initialized)
- {
- size_t i;
-
- for (i = 0; i < num_fatal_signals; i++)
- {
- struct sigaction action;
-
- if (sigaction (fatal_signals[i], NULL, &action) >= 0
- && get_handler (&action) == SIG_IGN)
- fatal_signals[i] = -1;
- }
-
- fatal_signals_initialized = true;
- }
-}
-
-
-/* ========================================================================= */
-
-
-typedef void (*action_t) (void);
-
-/* Type of an entry in the actions array.
- The 'action' field is accessed from within the fatal_signal_handler(),
- therefore we mark it as 'volatile'. */
-typedef struct
-{
- volatile action_t action;
-}
-actions_entry_t;
-
-/* The registered cleanup actions. */
-static actions_entry_t static_actions[32];
-static actions_entry_t * volatile actions = static_actions;
-static sig_atomic_t volatile actions_count = 0;
-static size_t actions_allocated = SIZEOF (static_actions);
-
-
-/* The saved signal handlers.
- Size 32 would not be sufficient: On HP-UX, SIGXCPU = 33, SIGXFSZ = 34. */
-static struct sigaction saved_sigactions[64];
-
-
-/* Uninstall the handlers. */
-static void
-uninstall_handlers (void)
-{
- size_t i;
-
- for (i = 0; i < num_fatal_signals; i++)
- if (fatal_signals[i] >= 0)
- {
- int sig = fatal_signals[i];
- if (saved_sigactions[sig].sa_handler == SIG_IGN)
- saved_sigactions[sig].sa_handler = SIG_DFL;
- sigaction (sig, &saved_sigactions[sig], NULL);
- }
-}
-
-
-/* The signal handler. It gets called asynchronously. */
-static void
-fatal_signal_handler (int sig)
-{
- for (;;)
- {
- /* Get the last registered cleanup action, in a reentrant way. */
- action_t action;
- size_t n = actions_count;
- if (n == 0)
- break;
- n--;
- actions_count = n;
- action = actions[n].action;
- /* Execute the action. */
- action ();
- }
-
- /* Now execute the signal's default action.
- If the signal being delivered was blocked, the re-raised signal would be
- delivered when this handler returns. But the way we install this handler,
- no signal is blocked, and the re-raised signal is delivered already
- during raise(). */
- uninstall_handlers ();
- raise (sig);
-}
-
-
-/* Install the handlers. */
-static void
-install_handlers (void)
-{
- size_t i;
- struct sigaction action;
-
- action.sa_handler = &fatal_signal_handler;
- /* If we get a fatal signal while executing fatal_signal_handler, enter
- fatal_signal_handler recursively, since it is reentrant. Hence no
- SA_RESETHAND. */
- action.sa_flags = SA_NODEFER;
- sigemptyset (&action.sa_mask);
- for (i = 0; i < num_fatal_signals; i++)
- if (fatal_signals[i] >= 0)
- {
- int sig = fatal_signals[i];
-
- if (!(sig < sizeof (saved_sigactions) / sizeof (saved_sigactions[0])))
- abort ();
- sigaction (sig, &action, &saved_sigactions[sig]);
- }
-}
-
-
-/* Register a cleanup function to be executed when a catchable fatal signal
- occurs. */
-void
-at_fatal_signal (action_t action)
-{
- static bool cleanup_initialized = false;
- if (!cleanup_initialized)
- {
- init_fatal_signals ();
- install_handlers ();
- cleanup_initialized = true;
- }
-
- if (actions_count == actions_allocated)
- {
- /* Extend the actions array. Note that we cannot use xrealloc(),
- because then the cleanup() function could access an already
- deallocated array. */
- actions_entry_t *old_actions = actions;
- size_t old_actions_allocated = actions_allocated;
- size_t new_actions_allocated = 2 * actions_allocated;
- actions_entry_t *new_actions =
- XNMALLOC (new_actions_allocated, actions_entry_t);
- size_t k;
-
- /* Don't use memcpy() here, because memcpy takes non-volatile arguments
- and is therefore not guaranteed to complete all memory stores before
- the next statement. */
- for (k = 0; k < old_actions_allocated; k++)
- new_actions[k] = old_actions[k];
- actions = new_actions;
- actions_allocated = new_actions_allocated;
- /* Now we can free the old actions array. */
- if (old_actions != static_actions)
- free (old_actions);
- }
- /* The two uses of 'volatile' in the types above (and ISO C 99 section
- 5.1.2.3.(5)) ensure that we increment the actions_count only after
- the new action has been written to the memory location
- actions[actions_count]. */
- actions[actions_count].action = action;
- actions_count++;
-}
-
-
-/* ========================================================================= */
-
-
-static sigset_t fatal_signal_set;
-
-static void
-init_fatal_signal_set (void)
-{
- static bool fatal_signal_set_initialized = false;
- if (!fatal_signal_set_initialized)
- {
- size_t i;
-
- init_fatal_signals ();
-
- sigemptyset (&fatal_signal_set);
- for (i = 0; i < num_fatal_signals; i++)
- if (fatal_signals[i] >= 0)
- sigaddset (&fatal_signal_set, fatal_signals[i]);
-
- fatal_signal_set_initialized = true;
- }
-}
-
-/* Temporarily delay the catchable fatal signals. */
-void
-block_fatal_signals (void)
-{
- init_fatal_signal_set ();
- sigprocmask (SIG_BLOCK, &fatal_signal_set, NULL);
-}
-
-/* Stop delaying the catchable fatal signals. */
-void
-unblock_fatal_signals (void)
-{
- init_fatal_signal_set ();
- sigprocmask (SIG_UNBLOCK, &fatal_signal_set, NULL);
-}
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