[tor-commits] [tor/master] Try to decouple process_signal() from anything not event-driven
nickm at torproject.org
nickm at torproject.org
Mon Aug 17 20:25:06 UTC 2015
commit f4f0b4326891e2e5907ff252c704c7f19bbfaf0d
Author: Nick Mathewson <nickm at torproject.org>
Date: Wed Aug 12 11:25:00 2015 -0400
Try to decouple process_signal() from anything not event-driven
This needs debugging; it currently breaks the stem tests.
---
src/or/control.c | 2 +-
src/or/main.c | 105 +++++++++++++++++++++++++++++++++++++++---------------
src/or/main.h | 2 +-
3 files changed, 78 insertions(+), 31 deletions(-)
diff --git a/src/or/control.c b/src/or/control.c
index 56f179c..a0004c3 100644
--- a/src/or/control.c
+++ b/src/or/control.c
@@ -1325,7 +1325,7 @@ handle_control_signal(control_connection_t *conn, uint32_t len,
if (sig == SIGTERM || sig == SIGINT)
connection_flush(TO_CONN(conn));
- process_signal(sig);
+ activate_signal(sig);
return 0;
}
diff --git a/src/or/main.c b/src/or/main.c
index a29387c..3ccb6e9 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -100,6 +100,7 @@ static int conn_close_if_marked(int i);
static void connection_start_reading_from_linked_conn(connection_t *conn);
static int connection_should_read_from_linked_conn(connection_t *conn);
static int run_main_loop_until_done(void);
+static void process_signal(int sig);
/********* START VARIABLES **********/
@@ -2249,7 +2250,6 @@ run_main_loop_until_done(void)
return loop_result;
}
-#ifndef _WIN32 /* Only called when we're willing to use signals */
/** Libevent callback: invoked when we get a signal.
*/
static void
@@ -2262,10 +2262,9 @@ signal_callback(int fd, short events, void *arg)
process_signal(sig);
}
-#endif
/** Do the work of acting on a signal received in <b>sig</b> */
-void
+static void
process_signal(int sig)
{
switch (sig)
@@ -2490,36 +2489,73 @@ exit_function(void)
#endif
}
-/** Set up the signal handlers for either parent or child. */
+#ifdef _WIN32
+#define UNIX_ONLY 0
+#else
+#define UNIX_ONLY 1
+#endif
+static struct {
+ int signal_value;
+ int try_to_register;
+ struct event *signal_event;
+} signal_handlers[] = {
+#ifdef SIGINT
+ { SIGINT, UNIX_ONLY, NULL }, /* do a controlled slow shutdown */
+#endif
+#ifdef SIGTERM
+ { SIGTERM, UNIX_ONLY, NULL }, /* to terminate now */
+#endif
+#ifdef SIGPIPE
+ { SIGPIPE, UNIX_ONLY, NULL }, /* otherwise SIGPIPE kills us */
+#endif
+#ifdef SIGUSR1
+ { SIGUSR1, UNIX_ONLY, NULL }, /* dump stats */
+#endif
+#ifdef SIGUSR2
+ { SIGUSR2, UNIX_ONLY, NULL }, /* go to loglevel debug */
+#endif
+#ifdef SIGHUP
+ { SIGHUP, UNIX_ONLY, NULL }, /* to reload config, retry conns, etc */
+#endif
+#ifdef SIGXFSZ
+ { SIGXFSZ, UNIX_ONLY, NULL }, /* handle file-too-big resource exhaustion */
+#endif
+#ifdef SIGCHLD
+ { SIGCHLD, UNIX_ONLY, NULL }, /* handle dns/cpu workers that exit */
+#endif
+ /* These are controller-only */
+ { SIGNEWNYM, 0, NULL },
+ { SIGCLEARDNSCACHE, 0, NULL },
+ { SIGHEARTBEAT, 0, NULL },
+ { -1, -1, NULL }
+};
+
+/** Set up the signal handlers for either parent or child process */
void
handle_signals(int is_parent)
{
-#ifndef _WIN32 /* do signal stuff only on Unix */
int i;
- static const int signals[] = {
- SIGINT, /* do a controlled slow shutdown */
- SIGTERM, /* to terminate now */
- SIGPIPE, /* otherwise SIGPIPE kills us */
- SIGUSR1, /* dump stats */
- SIGUSR2, /* go to loglevel debug */
- SIGHUP, /* to reload config, retry conns, etc */
-#ifdef SIGXFSZ
- SIGXFSZ, /* handle file-too-big resource exhaustion */
-#endif
- SIGCHLD, /* handle dns/cpu workers that exit */
- -1 };
- static struct event *signal_events[16]; /* bigger than it has to be. */
if (is_parent) {
- for (i = 0; signals[i] >= 0; ++i) {
- signal_events[i] = tor_evsignal_new(tor_libevent_get_base(), signals[i],
- signal_callback,
- /* Cast away const */
- (int*)&signals[i]);
- if (event_add(signal_events[i], NULL))
- log_warn(LD_BUG, "Error from libevent when adding event for signal %d",
- signals[i]);
+ for (i = 0; signal_handlers[i].signal_value >= 0; ++i) {
+ if (signal_handlers[i].try_to_register) {
+ signal_handlers[i].signal_event =
+ tor_evsignal_new(tor_libevent_get_base(),
+ signal_handlers[i].signal_value,
+ signal_callback,
+ &signal_handlers[i].signal_value);
+ if (event_add(signal_handlers[i].signal_event, NULL))
+ log_warn(LD_BUG, "Error from libevent when adding "
+ "event for signal %d",
+ signal_handlers[i].signal_value);
+ } else {
+ signal_handlers[i].signal_event =
+ tor_event_new(tor_libevent_get_base(), -1,
+ EV_SIGNAL, signal_callback,
+ &signal_handlers[i].signal_value);
+ }
}
} else {
+#ifndef _WIN32
struct sigaction action;
action.sa_flags = 0;
sigemptyset(&action.sa_mask);
@@ -2533,10 +2569,21 @@ handle_signals(int is_parent)
#ifdef SIGXFSZ
sigaction(SIGXFSZ, &action, NULL);
#endif
+#endif
+ }
+}
+
+/* Make sure the signal handler for signal_num will be called. */
+void
+activate_signal(int signal_num)
+{
+ int i;
+ for (i = 0; signal_handlers[i].signal_value >= 0; ++i) {
+ if (signal_handlers[i].signal_value == signal_num) {
+ event_active(signal_handlers[i].signal_event, EV_SIGNAL, 1);
+ return;
+ }
}
-#else /* MS windows */
- (void)is_parent;
-#endif /* signal stuff */
}
/** Main entry point for the Tor command-line client.
diff --git a/src/or/main.h b/src/or/main.h
index be0bd64..f31849f 100644
--- a/src/or/main.h
+++ b/src/or/main.h
@@ -60,7 +60,7 @@ MOCK_DECL(long,get_uptime,(void));
unsigned get_signewnym_epoch(void);
void handle_signals(int is_parent);
-void process_signal(int sig);
+void activate_signal(int signal_num);
int try_locking(const or_options_t *options, int err_if_locked);
int have_lockfile(void);
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