Nicholas Marriott <nicholas.marri...@gmail.com> writes:
> I wonder if to make it nicer we could unify the signal set
> functions into one set_signals(void (*)(int, short, void *)). And
> similarly could have one clear_signals function.
> All the processes could ignore SIGINT, SIGPIPE, SIGUSR2, SIGTSTP,
> SIGHUP, and all catch SIGCONT, SIGTERM, SIGWINCH, SIGCHLD,
> SIGUSR1, then the actual handler could just ignore the ones not
> wanted.
Handling a signal and doing nothing with it is different than using
SIG_IGN, in particular for SIGCHLD using SIG_IGN enables automatic
reaping of zombies (at least on Linux).
That being said, your approach is indeed cleaner so I implemented it
(patch follows), adding a wait() call in the main handler to fix the
original zombie issue.
Index: client.c
===================================================================
RCS file: /cvsroot/tmux/tmux/client.c,v
retrieving revision 1.90
diff -u -p -r1.90 client.c
--- client.c 4 Dec 2009 22:14:47 -0000 1.90
+++ client.c 28 Apr 2010 21:46:16 -0000
@@ -176,35 +176,12 @@ client_update_event(void)
__dead void
client_main(void)
{
- struct event ev_sigcont, ev_sigterm, ev_sigwinch;
- struct sigaction sigact;
-
logfile("client");
/* Note: event_init() has already been called. */
/* Set up signals. */
- memset(&sigact, 0, sizeof sigact);
- sigemptyset(&sigact.sa_mask);
- sigact.sa_flags = SA_RESTART;
- sigact.sa_handler = SIG_IGN;
- if (sigaction(SIGINT, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGPIPE, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGUSR1, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGUSR2, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGTSTP, &sigact, NULL) != 0)
- fatal("sigaction failed");
-
- signal_set(&ev_sigcont, SIGCONT, client_signal, NULL);
- signal_add(&ev_sigcont, NULL);
- signal_set(&ev_sigterm, SIGTERM, client_signal, NULL);
- signal_add(&ev_sigterm, NULL);
- signal_set(&ev_sigwinch, SIGWINCH, client_signal, NULL);
- signal_add(&ev_sigwinch, NULL);
+ set_signals(client_signal);
/*
* imsg_read in the first client poll loop (before the terminal has
@@ -250,6 +227,9 @@ client_signal(int sig, unused short even
fatal("sigaction failed");
client_write_server(MSG_WAKEUP, NULL, 0);
break;
+ default:
+ /* signal not handled here, ignore. */
+ return;
}
client_update_event();
Index: cmd-pipe-pane.c
===================================================================
RCS file: /cvsroot/tmux/tmux/cmd-pipe-pane.c,v
retrieving revision 1.10
diff -u -p -r1.10 cmd-pipe-pane.c
--- cmd-pipe-pane.c 4 Dec 2009 22:14:47 -0000 1.10
+++ cmd-pipe-pane.c 28 Apr 2010 21:46:16 -0000
@@ -90,7 +90,7 @@ cmd_pipe_pane_exec(struct cmd *self, str
case 0:
/* Child process. */
close(pipe_fd[0]);
- server_signal_clear();
+ clear_signals();
if (dup2(pipe_fd[1], STDIN_FILENO) == -1)
_exit(1);
Index: job.c
===================================================================
RCS file: /cvsroot/tmux/tmux/job.c,v
retrieving revision 1.16
diff -u -p -r1.16 job.c
--- job.c 6 Apr 2010 21:59:19 -0000 1.16
+++ job.c 28 Apr 2010 21:46:16 -0000
@@ -148,7 +148,7 @@ job_run(struct job *job)
case -1:
return (-1);
case 0: /* child */
- server_signal_clear();
+ clear_signals();
environ_push(&global_environ);
Index: server.c
===================================================================
RCS file: /cvsroot/tmux/tmux/server.c,v
retrieving revision 1.239
diff -u -p -r1.239 server.c
--- server.c 8 Apr 2010 07:54:43 -0000 1.239
+++ server.c 28 Apr 2010 21:46:16 -0000
@@ -48,9 +48,6 @@ struct clients dead_clients;
int server_fd;
int server_shutdown;
struct event server_ev_accept;
-struct event server_ev_sigterm;
-struct event server_ev_sigusr1;
-struct event server_ev_sigchld;
struct event server_ev_second;
int server_create_socket(void);
@@ -136,6 +133,12 @@ server_start(char *path)
}
close(pair[0]);
+ /* event_init() was called in our parent, we need to reinit. */
+ if (event_reinit(ev_base) != 0)
+ fatal("event_reinit failed");
+
+ clear_signals();
+
/*
* Must daemonise before loading configuration as the PID changes so
* $TMUX would be wrong for sessions created in the config file.
@@ -166,22 +169,6 @@ server_start(char *path)
setproctitle("server (%s)", rpathbuf);
#endif
-#ifdef HAVE_BROKEN_KQUEUE
- if (setenv("EVENT_NOKQUEUE", "1", 1) != 0)
- fatal("setenv failed");
-#endif
-#ifdef HAVE_BROKEN_POLL
- if (setenv("EVENT_NOPOLL", "1", 1) != 0)
- fatal("setenv failed");
-#endif
- event_init();
-#ifdef HAVE_BROKEN_KQUEUE
- unsetenv("EVENT_NOKQUEUE");
-#endif
-#ifdef HAVE_BROKEN_POLL
- unsetenv("EVENT_NOPOLL");
-#endif
-
server_fd = server_create_socket();
server_client_create(pair[1]);
@@ -220,7 +207,7 @@ server_start(char *path)
evtimer_set(&server_ev_second, server_second_callback, NULL);
evtimer_add(&server_ev_second, &tv);
- server_signal_set();
+ set_signals(server_signal_callback);
server_loop();
exit(0);
}
@@ -359,61 +346,6 @@ server_accept_callback(int fd, short eve
server_client_create(newfd);
}
-/* Set up server signal handling. */
-void
-server_signal_set(void)
-{
- struct sigaction sigact;
-
- memset(&sigact, 0, sizeof sigact);
- sigemptyset(&sigact.sa_mask);
- sigact.sa_flags = SA_RESTART;
- sigact.sa_handler = SIG_IGN;
- if (sigaction(SIGINT, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGPIPE, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGUSR2, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGTSTP, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGHUP, &sigact, NULL) != 0)
- fatal("sigaction failed");
-
- signal_set(&server_ev_sigchld, SIGCHLD, server_signal_callback, NULL);
- signal_add(&server_ev_sigchld, NULL);
- signal_set(&server_ev_sigterm, SIGTERM, server_signal_callback, NULL);
- signal_add(&server_ev_sigterm, NULL);
- signal_set(&server_ev_sigusr1, SIGUSR1, server_signal_callback, NULL);
- signal_add(&server_ev_sigusr1, NULL);
-}
-
-/* Destroy server signal events. */
-void
-server_signal_clear(void)
-{
- struct sigaction sigact;
-
- memset(&sigact, 0, sizeof sigact);
- sigemptyset(&sigact.sa_mask);
- sigact.sa_flags = SA_RESTART;
- sigact.sa_handler = SIG_DFL;
- if (sigaction(SIGINT, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGPIPE, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGUSR2, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGTSTP, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGHUP, &sigact, NULL) != 0)
- fatal("sigaction failed");
-
- signal_del(&server_ev_sigchld);
- signal_del(&server_ev_sigterm);
- signal_del(&server_ev_sigusr1);
-}
-
/* Signal handler. */
/* ARGSUSED */
void
@@ -435,6 +367,9 @@ server_signal_callback(int sig, unused s
EV_READ|EV_PERSIST, server_accept_callback, NULL);
event_add(&server_ev_accept, NULL);
break;
+ default:
+ /* signal not handled here, ignore. */
+ return;
}
}
Index: signal.c
===================================================================
RCS file: signal.c
diff -N signal.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ signal.c 28 Apr 2010 21:46:16 -0000
@@ -0,0 +1,88 @@
+/* $Id$ */
+
+/*
+ * Copyright (c) 2007 Nicholas Marriott <n...@users.sourceforge.net>
+ * Copyright (c) 2010 Romain Francoise <rfranco...@debian.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <string.h>
+#include <signal.h>
+
+#include "tmux.h"
+
+struct event ev_sigchld;
+struct event ev_sigcont;
+struct event ev_sigterm;
+struct event ev_sigusr1;
+struct event ev_sigwinch;
+
+void
+set_signals(void(*handler)(int, short, unused void *))
+{
+ struct sigaction sigact;
+
+ memset(&sigact, 0, sizeof sigact);
+ sigemptyset(&sigact.sa_mask);
+ sigact.sa_flags = SA_RESTART;
+ sigact.sa_handler = SIG_IGN;
+ if (sigaction(SIGINT, &sigact, NULL) != 0)
+ fatal("sigaction failed");
+ if (sigaction(SIGPIPE, &sigact, NULL) != 0)
+ fatal("sigaction failed");
+ if (sigaction(SIGUSR2, &sigact, NULL) != 0)
+ fatal("sigaction failed");
+ if (sigaction(SIGTSTP, &sigact, NULL) != 0)
+ fatal("sigaction failed");
+ if (sigaction(SIGHUP, &sigact, NULL) != 0)
+ fatal("sigaction failed");
+
+ signal_set(&ev_sigchld, SIGCHLD, handler, NULL);
+ signal_add(&ev_sigchld, NULL);
+ signal_set(&ev_sigcont, SIGCONT, handler, NULL);
+ signal_add(&ev_sigcont, NULL);
+ signal_set(&ev_sigterm, SIGTERM, handler, NULL);
+ signal_add(&ev_sigterm, NULL);
+ signal_set(&ev_sigusr1, SIGUSR1, handler, NULL);
+ signal_add(&ev_sigusr1, NULL);
+ signal_set(&ev_sigwinch, SIGWINCH, handler, NULL);
+ signal_add(&ev_sigwinch, NULL);
+}
+
+void
+clear_signals(void)
+{
+ struct sigaction sigact;
+
+ memset(&sigact, 0, sizeof sigact);
+ sigemptyset(&sigact.sa_mask);
+ sigact.sa_flags = SA_RESTART;
+ sigact.sa_handler = SIG_DFL;
+ if (sigaction(SIGINT, &sigact, NULL) != 0)
+ fatal("sigaction failed");
+ if (sigaction(SIGPIPE, &sigact, NULL) != 0)
+ fatal("sigaction failed");
+ if (sigaction(SIGUSR2, &sigact, NULL) != 0)
+ fatal("sigaction failed");
+ if (sigaction(SIGTSTP, &sigact, NULL) != 0)
+ fatal("sigaction failed");
+ if (sigaction(SIGHUP, &sigact, NULL) != 0)
+ fatal("sigaction failed");
+
+ event_del(&ev_sigchld);
+ event_del(&ev_sigcont);
+ event_del(&ev_sigterm);
+ event_del(&ev_sigusr1);
+ event_del(&ev_sigwinch);
+}
Index: tmux.c
===================================================================
RCS file: /cvsroot/tmux/tmux/tmux.c,v
retrieving revision 1.205
diff -u -p -r1.205 tmux.c
--- tmux.c 22 Apr 2010 21:48:49 -0000 1.205
+++ tmux.c 28 Apr 2010 21:46:16 -0000
@@ -18,6 +18,7 @@
#include <sys/types.h>
#include <sys/stat.h>
+#include <sys/wait.h>
#include <errno.h>
#include <event.h>
@@ -40,6 +41,8 @@ struct options global_s_options; /* ses
struct options global_w_options; /* window options */
struct environ global_environ;
+struct event_base *ev_base;
+
int debug_level;
time_t start_time;
char *socket_path;
@@ -57,11 +60,8 @@ char *makesockpath(const char *);
__dead void shell_exec(const char *, const char *);
struct imsgbuf *main_ibuf;
-struct event main_ev_sigterm;
int main_exitval;
-void main_set_signals(void);
-void main_clear_signals(void);
void main_signal(int, short, unused void *);
void main_callback(int, short, void *);
void main_dispatch(const char *);
@@ -241,7 +241,6 @@ main(int argc, char **argv)
struct keylist *keylist;
struct env_data envdata;
struct msg_command_data cmddata;
- struct sigaction sigact;
char *s, *shellcmd, *path, *label, *home, *cause;
char cwd[MAXPATHLEN], **var;
void *buf;
@@ -541,18 +540,6 @@ main(int argc, char **argv)
exit(1);
}
- /* Catch SIGCHLD to avoid a zombie when starting the server. */
- memset(&sigact, 0, sizeof sigact);
- sigemptyset(&sigact.sa_mask);
- sigact.sa_handler = SIG_IGN;
- if (sigaction(SIGCHLD, &sigact, NULL) != 0)
- fatal("sigaction failed");
-
- /* Initialise the client socket/start the server. */
- if ((main_ibuf = client_init(path, cmdflags, flags)) == NULL)
- exit(1);
- xfree(path);
-
#ifdef HAVE_BROKEN_KQUEUE
if (setenv("EVENT_NOKQUEUE", "1", 1) != 0)
fatal("setenv failed");
@@ -561,7 +548,7 @@ main(int argc, char **argv)
if (setenv("EVENT_NOPOLL", "1", 1) != 0)
fatal("setenv failed");
#endif
- event_init();
+ ev_base = event_init();
#ifdef HAVE_BROKEN_KQUEUE
unsetenv("EVENT_NOKQUEUE");
#endif
@@ -569,9 +556,14 @@ main(int argc, char **argv)
unsetenv("EVENT_NOPOLL");
#endif
- imsg_compose(main_ibuf, msg, PROTOCOL_VERSION, -1, -1, buf, len);
+ set_signals(main_signal);
- main_set_signals();
+ /* Initialise the client socket/start the server. */
+ if ((main_ibuf = client_init(path, cmdflags, flags)) == NULL)
+ exit(1);
+ xfree(path);
+
+ imsg_compose(main_ibuf, msg, PROTOCOL_VERSION, -1, -1, buf, len);
events = EV_READ;
if (main_ibuf->w.queued > 0)
@@ -581,65 +573,26 @@ main(int argc, char **argv)
main_exitval = 0;
event_dispatch();
- main_clear_signals();
+ clear_signals();
client_main(); /* doesn't return */
}
-void
-main_set_signals(void)
-{
- struct sigaction sigact;
-
- memset(&sigact, 0, sizeof sigact);
- sigemptyset(&sigact.sa_mask);
- sigact.sa_flags = SA_RESTART;
- sigact.sa_handler = SIG_IGN;
- if (sigaction(SIGINT, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGPIPE, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGUSR1, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGUSR2, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGTSTP, &sigact, NULL) != 0)
- fatal("sigaction failed");
-
- signal_set(&main_ev_sigterm, SIGTERM, main_signal, NULL);
- signal_add(&main_ev_sigterm, NULL);
-}
-
-void
-main_clear_signals(void)
-{
- struct sigaction sigact;
-
- memset(&sigact, 0, sizeof sigact);
- sigemptyset(&sigact.sa_mask);
- sigact.sa_flags = SA_RESTART;
- sigact.sa_handler = SIG_DFL;
- if (sigaction(SIGINT, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGPIPE, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGUSR1, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGUSR2, &sigact, NULL) != 0)
- fatal("sigaction failed");
- if (sigaction(SIGTSTP, &sigact, NULL) != 0)
- fatal("sigaction failed");
-
- event_del(&main_ev_sigterm);
-}
-
/* ARGSUSED */
void
main_signal(int sig, unused short events, unused void *data)
{
+ int st;
+
switch (sig) {
case SIGTERM:
exit(1);
+ case SIGCHLD:
+ wait(&st);
+ break;
+ default:
+ /* signal not handled here, ignore. */
+ return;
}
}
@@ -718,7 +671,7 @@ main_dispatch(const char *shellcmd)
memcpy(&shelldata, imsg.data, sizeof shelldata);
shelldata.shell[(sizeof shelldata.shell) - 1] = '\0';
- main_clear_signals();
+ clear_signals();
shell_exec(shelldata.shell, shellcmd);
default:
Index: tmux.h
===================================================================
RCS file: /cvsroot/tmux/tmux/tmux.h,v
retrieving revision 1.555
diff -u -p -r1.555 tmux.h
--- tmux.h 6 Apr 2010 21:59:19 -0000 1.555
+++ tmux.h 28 Apr 2010 21:46:17 -0000
@@ -1252,6 +1252,7 @@ extern struct options global_options;
extern struct options global_s_options;
extern struct options global_w_options;
extern struct environ global_environ;
+extern struct event_base *ev_base;
extern char *cfg_file;
extern int debug_level;
extern int be_quiet;
@@ -1582,8 +1583,6 @@ const char *key_string_lookup_key(int);
extern struct clients clients;
extern struct clients dead_clients;
int server_start(char *);
-void server_signal_set(void);
-void server_signal_clear(void);
void server_update_socket(void);
/* server-client.c */
@@ -1899,6 +1898,10 @@ void window_choose_ready(struct window
void queue_window_name(struct window *);
char *default_window_name(struct window *);
+/* signal.c */
+void set_signals(void(*handler)(int, short, unused void *));
+void clear_signals(void);
+
/* session.c */
extern struct sessions sessions;
extern struct sessions dead_sessions;
Index: window.c
===================================================================
RCS file: /cvsroot/tmux/tmux/window.c,v
retrieving revision 1.130
diff -u -p -r1.130 window.c
--- window.c 6 Apr 2010 21:59:19 -0000 1.130
+++ window.c 28 Apr 2010 21:46:17 -0000
@@ -527,7 +527,7 @@ window_pane_spawn(struct window_pane *wp
environ_push(env);
- server_signal_clear();
+ clear_signals();
log_close();
if (*wp->cmd != '\0') {
------------------------------------------------------------------------------
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