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,
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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#include "includes.h"
+#include <signal.h>
+#include "replace.h"
#include "system/filesys.h"
#include "system/select.h"
-#include "lib/util/dlinklist.h"
-#include "lib/events/events.h"
-#include "lib/events/events_internal.h"
+#include "events.h"
+#include "events_internal.h"
#define NUM_SIGNALS 64
/* maximum number of SA_SIGINFO signals to hold in the queue */
#define SA_INFO_QUEUE_COUNT 10
+struct sigcounter {
+ uint32_t count;
+ uint32_t seen;
+};
+
+#define SIG_INCREMENT(s) (s).count++
+#define SIG_SEEN(s, n) (s).seen += (n)
+#define SIG_PENDING(s) ((s).seen != (s).count)
+
+
/*
the poor design of signals means that this table must be static global
*/
-static struct {
+static struct sig_state {
struct signal_event *sig_handlers[NUM_SIGNALS];
- struct sigaction oldact[NUM_SIGNALS];
- uint32_t signal_count[NUM_SIGNALS];
- uint32_t got_signal;
+ struct sigaction *oldact[NUM_SIGNALS];
+ struct sigcounter signal_count[NUM_SIGNALS];
+ struct sigcounter got_signal;
int pipe_hack[2];
#ifdef SA_SIGINFO
/* with SA_SIGINFO we get quite a lot of info per signal */
- siginfo_t sig_info[NUM_SIGNALS][SA_INFO_QUEUE_COUNT];
+ siginfo_t *sig_info[NUM_SIGNALS];
+ struct sigcounter sig_blocked[NUM_SIGNALS];
#endif
-} sig_state;
+} *sig_state;
+/*
+ return number of sigcounter events not processed yet
+*/
+static uint32_t sig_count(struct sigcounter s)
+{
+ if (s.count >= s.seen) {
+ return s.count - s.seen;
+ }
+ return 1 + (0xFFFFFFFF & ~(s.seen - s.count));
+}
/*
signal handler - redirects to registered signals
static void signal_handler(int signum)
{
char c = 0;
- sig_state.signal_count[signum]++;
- sig_state.got_signal++;
+ SIG_INCREMENT(sig_state->signal_count[signum]);
+ SIG_INCREMENT(sig_state->got_signal);
/* doesn't matter if this pipe overflows */
- write(sig_state.pipe_hack[1], &c, 1);
+ write(sig_state->pipe_hack[1], &c, 1);
}
#ifdef SA_SIGINFO
*/
static void signal_handler_info(int signum, siginfo_t *info, void *uctx)
{
- sig_state.sig_info[signum][sig_state.signal_count[signum]] = *info;
+ uint32_t count = sig_count(sig_state->signal_count[signum]);
+ sig_state->sig_info[signum][count] = *info;
signal_handler(signum);
/* handle SA_SIGINFO */
- if (sig_state.signal_count[signum] == SA_INFO_QUEUE_COUNT) {
+ if (count+1 == SA_INFO_QUEUE_COUNT) {
/* we've filled the info array - block this signal until
these ones are delivered */
sigset_t set;
sigemptyset(&set);
sigaddset(&set, signum);
sigprocmask(SIG_BLOCK, &set, NULL);
+ SIG_INCREMENT(sig_state->sig_blocked[signum]);
}
}
#endif
static int signal_event_destructor(struct signal_event *se)
{
se->event_ctx->num_signal_handlers--;
- DLIST_REMOVE(sig_state.sig_handlers[se->signum], se);
- if (sig_state.sig_handlers[se->signum] == NULL) {
+ DLIST_REMOVE(sig_state->sig_handlers[se->signum], se);
+ if (sig_state->sig_handlers[se->signum] == NULL) {
/* restore old handler, if any */
- sigaction(se->signum, &sig_state.oldact[se->signum], NULL);
+ sigaction(se->signum, sig_state->oldact[se->signum], NULL);
+ sig_state->oldact[se->signum] = NULL;
+#ifdef SA_SIGINFO
+ if (se->sa_flags & SA_SIGINFO) {
+ talloc_free(sig_state->sig_info[se->signum]);
+ sig_state->sig_info[se->signum] = NULL;
+ }
+#endif
}
return 0;
}
{
char c[16];
/* its non-blocking, doesn't matter if we read too much */
- read(sig_state.pipe_hack[0], c, sizeof(c));
+ read(sig_state->pipe_hack[0], c, sizeof(c));
}
/*
return NULL;
}
+ /* the sig_state needs to be on a global context as it can last across
+ multiple event contexts */
+ if (sig_state == NULL) {
+ sig_state = talloc_zero(talloc_autofree_context(), struct sig_state);
+ if (sig_state == NULL) {
+ return NULL;
+ }
+ }
+
se = talloc(mem_ctx?mem_ctx:ev, struct signal_event);
if (se == NULL) return NULL;
se->private_data = private_data;
se->signum = signum;
se->sa_flags = sa_flags;
+
+ /* Ensure, no matter the destruction order, that we always have a handle on the global sig_state */
+ if (!talloc_reference(se, sig_state)) {
+ return NULL;
+ }
/* only install a signal handler if not already installed */
- if (sig_state.sig_handlers[signum] == NULL) {
+ if (sig_state->sig_handlers[signum] == NULL) {
struct sigaction act;
ZERO_STRUCT(act);
act.sa_handler = signal_handler;
if (sa_flags & SA_SIGINFO) {
act.sa_handler = NULL;
act.sa_sigaction = signal_handler_info;
+ if (sig_state->sig_info[signum] == NULL) {
+ sig_state->sig_info[signum] = talloc_array(sig_state, siginfo_t, SA_INFO_QUEUE_COUNT);
+ if (sig_state->sig_info[signum] == NULL) {
+ talloc_free(se);
+ return NULL;
+ }
+ }
}
#endif
- if (sigaction(signum, &act, &sig_state.oldact[signum]) == -1) {
+ sig_state->oldact[signum] = talloc(sig_state, struct sigaction);
+ if (sig_state->oldact[signum] == NULL) {
+ talloc_free(se);
+ return NULL;
+ }
+ if (sigaction(signum, &act, sig_state->oldact[signum]) == -1) {
talloc_free(se);
return NULL;
}
}
- DLIST_ADD(sig_state.sig_handlers[signum], se);
+ DLIST_ADD(sig_state->sig_handlers[signum], se);
talloc_set_destructor(se, signal_event_destructor);
/* we need to setup the pipe hack handler if not already
setup */
if (ev->pipe_fde == NULL) {
- if (sig_state.pipe_hack[0] == 0 &&
- sig_state.pipe_hack[1] == 0) {
- pipe(sig_state.pipe_hack);
- set_blocking(sig_state.pipe_hack[0], False);
- set_blocking(sig_state.pipe_hack[1], False);
+ if (sig_state->pipe_hack[0] == 0 &&
+ sig_state->pipe_hack[1] == 0) {
+ pipe(sig_state->pipe_hack);
+ ev_set_blocking(sig_state->pipe_hack[0], false);
+ ev_set_blocking(sig_state->pipe_hack[1], false);
}
- ev->pipe_fde = event_add_fd(ev, ev, sig_state.pipe_hack[0],
+ ev->pipe_fde = event_add_fd(ev, ev, sig_state->pipe_hack[0],
EVENT_FD_READ, signal_pipe_handler, NULL);
}
ev->num_signal_handlers++;
int common_event_check_signal(struct event_context *ev)
{
int i;
- if (sig_state.got_signal == 0) {
+
+ if (!sig_state || !SIG_PENDING(sig_state->got_signal)) {
return 0;
}
for (i=0;i<NUM_SIGNALS+1;i++) {
- uint32_t count = sig_state.signal_count[i];
- if (count != 0) {
- struct signal_event *se, *next;
- for (se=sig_state.sig_handlers[i];se;se=next) {
- next = se->next;
+ struct signal_event *se, *next;
+ struct sigcounter counter = sig_state->signal_count[i];
+ uint32_t count = sig_count(counter);
+
+ if (count == 0) {
+ continue;
+ }
+ for (se=sig_state->sig_handlers[i];se;se=next) {
+ next = se->next;
#ifdef SA_SIGINFO
- if (se->sa_flags & SA_SIGINFO) {
- int j;
- for (j=0;j<count;j++) {
- se->handler(ev, se, i, 1,
- (void*)&sig_state.sig_info[i][j],
- se->private_data);
- }
- if (count == SA_INFO_QUEUE_COUNT) {
- /* we'd filled the queue, unblock the
- signal now */
- sigset_t set;
- sigemptyset(&set);
- sigaddset(&set, i);
- sigprocmask(SIG_UNBLOCK, &set, NULL);
- }
- continue;
+ if (se->sa_flags & SA_SIGINFO) {
+ int j;
+ for (j=0;j<count;j++) {
+ /* note the use of the sig_info array as a
+ ring buffer */
+ int ofs = ((count-1) + j) % SA_INFO_QUEUE_COUNT;
+ se->handler(ev, se, i, 1,
+ (void*)&sig_state->sig_info[i][ofs],
+ se->private_data);
+ }
+ if (SIG_PENDING(sig_state->sig_blocked[i])) {
+ /* we'd filled the queue, unblock the
+ signal now */
+ sigset_t set;
+ sigemptyset(&set);
+ sigaddset(&set, i);
+ SIG_SEEN(sig_state->sig_blocked[i],
+ sig_count(sig_state->sig_blocked[i]));
+ sigprocmask(SIG_UNBLOCK, &set, NULL);
}
-#endif
- se->handler(ev, se, i, count, NULL, se->private_data);
if (se->sa_flags & SA_RESETHAND) {
talloc_free(se);
}
+ continue;
+ }
+#endif
+ se->handler(ev, se, i, count, NULL, se->private_data);
+ if (se->sa_flags & SA_RESETHAND) {
+ talloc_free(se);
}
- sig_state.signal_count[i] -= count;
- sig_state.got_signal -= count;
}
+ SIG_SEEN(sig_state->signal_count[i], count);
+ SIG_SEEN(sig_state->got_signal, count);
}
return 1;