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author | Jelmer Vernooij <jelmer@samba.org> | 2008-12-18 14:54:57 +0000 |
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committer | Jelmer Vernooij <jelmer@samba.org> | 2008-12-18 14:54:57 +0000 |
commit | d14c8604653d39dd25736279d34930ee7a3ae103 (patch) | |
tree | 626f700b9b42b798ed7459a5cba5cd27aca9753e /source4/lib/events/events_signal.c | |
parent | 0c0b9c738f0fc1bf8aa64533a5e4e0635b84f58f (diff) | |
parent | fc31f2c5269fd405be96b9a036baf35a60141ccf (diff) | |
download | samba-d14c8604653d39dd25736279d34930ee7a3ae103.tar.gz samba-d14c8604653d39dd25736279d34930ee7a3ae103.tar.bz2 samba-d14c8604653d39dd25736279d34930ee7a3ae103.zip |
Merge branch 'master' of ssh://git.samba.org/data/git/samba into pyregistry
Diffstat (limited to 'source4/lib/events/events_signal.c')
-rw-r--r-- | source4/lib/events/events_signal.c | 291 |
1 files changed, 0 insertions, 291 deletions
diff --git a/source4/lib/events/events_signal.c b/source4/lib/events/events_signal.c deleted file mode 100644 index 652df53d4b..0000000000 --- a/source4/lib/events/events_signal.c +++ /dev/null @@ -1,291 +0,0 @@ -/* - Unix SMB/CIFS implementation. - - common events code for signal events - - Copyright (C) Andrew Tridgell 2007 - - 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 <signal.h> -#include "replace.h" -#include "system/filesys.h" -#include "system/select.h" -#include "events.h" -#include "events_internal.h" -#include "events_util.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 sig_state { - struct signal_event *sig_handlers[NUM_SIGNALS+1]; - struct sigaction *oldact[NUM_SIGNALS+1]; - struct sigcounter signal_count[NUM_SIGNALS+1]; - 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+1]; - struct sigcounter sig_blocked[NUM_SIGNALS+1]; -#endif -} *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_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); -} - -#ifdef SA_SIGINFO -/* - signal handler with SA_SIGINFO - redirects to registered signals -*/ -static void signal_handler_info(int signum, siginfo_t *info, void *uctx) -{ - uint32_t count = sig_count(sig_state->signal_count[signum]); - sig_state->sig_info[signum][count] = *info; - - signal_handler(signum); - - /* handle SA_SIGINFO */ - 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 - -/* - destroy a signal event -*/ -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) { - /* restore old handler, if any */ - 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; -} - -/* - this is part of the pipe hack needed to avoid the signal race condition -*/ -static void signal_pipe_handler(struct event_context *ev, struct fd_event *fde, - uint16_t flags, void *private) -{ - char c[16]; - /* its non-blocking, doesn't matter if we read too much */ - read(sig_state->pipe_hack[0], c, sizeof(c)); -} - -/* - add a signal event - return NULL on failure (memory allocation error) -*/ -struct signal_event *common_event_add_signal(struct event_context *ev, - TALLOC_CTX *mem_ctx, - int signum, - int sa_flags, - event_signal_handler_t handler, - void *private_data) -{ - struct signal_event *se; - - if (signum >= NUM_SIGNALS) { - 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->event_ctx = ev; - se->handler = handler; - 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) { - struct sigaction act; - ZERO_STRUCT(act); - act.sa_handler = signal_handler; - act.sa_flags = sa_flags; -#ifdef SA_SIGINFO - 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 - 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); - - 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); - 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], - EVENT_FD_READ, signal_pipe_handler, NULL); - } - ev->num_signal_handlers++; - - return se; -} - - -/* - check if a signal is pending - return != 0 if a signal was pending -*/ -int common_event_check_signal(struct event_context *ev) -{ - int i; - - if (!sig_state || !SIG_PENDING(sig_state->got_signal)) { - return 0; - } - - for (i=0;i<NUM_SIGNALS+1;i++) { - 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++) { - /* 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); - } - 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_SEEN(sig_state->signal_count[i], count); - SIG_SEEN(sig_state->got_signal, count); - } - - return 1; -} |