X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libust%2Ftracectl.c;h=ac551d50e802afec1bcd3a1abdcba6cddbf1c326;hb=5f9aacae75a4181a54bf16f31ce8e18229dddc60;hp=3624b867f6d9f7a39bcae586878b00ae3abdd0b2;hpb=a80e6dd803cfde798019825ae8858015fa702d6b;p=ust.git

diff --git a/libust/tracectl.c b/libust/tracectl.c
index 3624b86..ac551d5 100644
--- a/libust/tracectl.c
+++ b/libust/tracectl.c
@@ -15,10 +15,16 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  */
 
+/* This file contains the implementation of the UST listener thread, which
+ * receives trace control commands. It also coordinates the initialization of
+ * libust.
+ */
+
 #define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>
+#include <pthread.h>
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/socket.h>
@@ -48,6 +54,8 @@
  */
 s64 pidunique = -1LL;
 
+extern struct chan_info_struct chan_infos[];
+
 struct list_head blocked_consumers = LIST_HEAD_INIT(blocked_consumers);
 
 static struct ustcomm_app ustcomm_app;
@@ -461,7 +469,6 @@ static int do_cmd_get_subbuf_size(const char *recvbuf, struct ustcomm_source *sr
 static unsigned int pow2_higher_or_eq(unsigned int v)
 {
 	int hb = fls(v);
-	int hbm1 = hb-1;
 	int retval = 1<<(hb-1);
 
 	if(v-retval == 0)
@@ -780,6 +787,15 @@ static void listener_cleanup(void *ptr)
 	ustcomm_fini_app(&ustcomm_app, 0);
 }
 
+static void do_cmd_force_switch()
+{
+	struct blocked_consumer *bc;
+
+	list_for_each_entry(bc, &blocked_consumers, list) {
+		ltt_force_switch(bc->buf, FORCE_FLUSH);
+	}
+}
+
 int process_client_cmd(char *recvbuf, struct ustcomm_source *src)
 {
 	int result;
@@ -986,6 +1002,28 @@ int process_client_cmd(char *recvbuf, struct ustcomm_source *src)
 
 		free(reply);
 	}
+	else if(nth_token_is(recvbuf, "get_sock_path", 0) == 1) {
+		char *reply = getenv("UST_DAEMON_SOCKET");
+		if(!reply) {
+			asprintf(&reply, "%s/%s", SOCK_DIR, "ustd");
+			result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
+			free(reply);
+		}
+		else {
+			result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
+		}
+		if(result)
+			ERR("ustcomm_send_reply failed");
+	}
+	else if(nth_token_is(recvbuf, "set_sock_path", 0) == 1) {
+		char *sock_path = nth_token(recvbuf, 1);
+		result = setenv("UST_DAEMON_SOCKET", sock_path, 1);
+		if(result)
+			ERR("cannot set UST_DAEMON_SOCKET environment variable");
+	}
+	else if(nth_token_is(recvbuf, "force_switch", 0) == 1) {
+		do_cmd_force_switch();
+	}
 	else {
 		ERR("unable to parse message: %s", recvbuf);
 	}
@@ -1031,18 +1069,40 @@ static pthread_t listener_thread;
 void create_listener(void)
 {
 	int result;
+	sigset_t sig_all_blocked;
+	sigset_t orig_parent_mask;
 
 	if(have_listener) {
 		WARN("not creating listener because we already had one");
 		return;
 	}
 
+	/* A new thread created by pthread_create inherits the signal mask
+	 * from the parent. To avoid any signal being received by the
+	 * listener thread, we block all signals temporarily in the parent,
+	 * while we create the listener thread.
+	 */
+
+	sigfillset(&sig_all_blocked);
+
+	result = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_parent_mask);
+	if(result) {
+		PERROR("pthread_sigmask: %s", strerror(result));
+	}
+
 	result = pthread_create(&listener_thread, NULL, listener_main, NULL);
 	if(result == -1) {
 		PERROR("pthread_create");
 	}
 
-	have_listener = 1;
+	/* Restore original signal mask in parent */
+	result = pthread_sigmask(SIG_SETMASK, &orig_parent_mask, NULL);
+	if(result) {
+		PERROR("pthread_sigmask: %s", strerror(result));
+	}
+	else {
+		have_listener = 1;
+	}
 }
 
 static int init_socket(void)
@@ -1092,6 +1152,11 @@ static void __attribute__((constructor)) init()
 {
 	int result;
 	char* autoprobe_val = NULL;
+	char* subbuffer_size_val = NULL;
+	char* subbuffer_count_val = NULL;
+	unsigned int subbuffer_size;
+	unsigned int subbuffer_count;
+	unsigned int power;
 
 	/* Assign the pidunique, to be able to differentiate the processes with same
 	 * pid, (before and after an exec).
@@ -1175,6 +1240,23 @@ static void __attribute__((constructor)) init()
 		}
 	}
 
+	subbuffer_size_val = getenv("UST_SUBBUF_SIZE");
+	if(subbuffer_size_val) {
+		sscanf(subbuffer_size_val, "%u", &subbuffer_size);
+		power = pow2_higher_or_eq(subbuffer_size);
+		if(power != subbuffer_size)
+			WARN("using the next power of two for buffer size = %u\n", power);
+		chan_infos[LTT_CHANNEL_UST].def_subbufsize = power;
+	}
+
+	subbuffer_count_val = getenv("UST_SUBBUF_NUM");
+	if(subbuffer_count_val) {
+		sscanf(subbuffer_count_val, "%u", &subbuffer_count);
+		if(subbuffer_count < 2)
+			subbuffer_count = 2;
+		chan_infos[LTT_CHANNEL_UST].def_subbufcount = subbuffer_count;
+	}
+
 	if(getenv("UST_TRACE")) {
 		char trace_name[] = "auto";
 		char trace_type[] = "ustrelay";
@@ -1241,7 +1323,6 @@ static void __attribute__((constructor)) init()
 		inform_consumer_daemon(trace_name);
 	}
 
-
 	return;
 
 	/* should decrementally destroy stuff if error */
@@ -1319,10 +1400,13 @@ int restarting_usleep(useconds_t usecs)
 	return result;
 }
 
-static void stop_listener()
+static void stop_listener(void)
 {
 	int result;
 
+	if(!have_listener)
+		return;
+
 	result = pthread_cancel(listener_thread);
 	if(result != 0) {
 		ERR("pthread_cancel: %s", strerror(result));