From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Tue, 26 Nov 2019 20:15:33 +0000 (-0500)
Subject: relayd: initialize the global fd tracker from fd_cap option
X-Git-Tag: v2.12.0-rc1~65
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=00e3b7f1faebd0595329a8532abbb9e77e5e2149;p=lttng-tools.git

relayd: initialize the global fd tracker from fd_cap option

Initialize the relay daemon's global fd tracker from the current
fd-cap configuration. This is in preparation for follow-up patches
which will introduce the tracking of the various file descriptor
backed resources to the relay daemon.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Iaabb80f1fb4d24345b750503c90388f94025159d
---

diff --git a/src/bin/lttng-relayd/Makefile.am b/src/bin/lttng-relayd/Makefile.am
index 8b903680a..4fc35dc0f 100644
--- a/src/bin/lttng-relayd/Makefile.am
+++ b/src/bin/lttng-relayd/Makefile.am
@@ -36,4 +36,5 @@ lttng_relayd_LDADD = -lurcu-common -lurcu \
 		$(top_builddir)/src/common/health/libhealth.la \
 		$(top_builddir)/src/common/config/libconfig.la \
 		$(top_builddir)/src/common/testpoint/libtestpoint.la \
+		$(top_builddir)/src/common/fd-tracker/libfd-tracker.la \
 		$(top_builddir)/src/lib/lttng-ctl/liblttng-ctl.la
diff --git a/src/bin/lttng-relayd/lttng-relayd.h b/src/bin/lttng-relayd/lttng-relayd.h
index 748083ddf..fc68c513f 100644
--- a/src/bin/lttng-relayd/lttng-relayd.h
+++ b/src/bin/lttng-relayd/lttng-relayd.h
@@ -25,6 +25,7 @@
 #include <urcu/wfcqueue.h>
 
 #include <common/hashtable/hashtable.h>
+#include <common/fd-tracker/fd-tracker.h>
 
 struct sessiond_trace_chunk_registry;
 
@@ -60,6 +61,8 @@ extern enum relay_group_output_by opt_group_output_by;
 
 extern int thread_quit_pipe[2];
 
+extern struct fd_tracker *the_fd_tracker;
+
 void lttng_relay_notify_ready(void);
 int lttng_relay_stop_threads(void);
 
diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
index 07e7a0122..f1f03d1bd 100644
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -63,6 +63,7 @@
 #include <common/dynamic-buffer.h>
 #include <common/buffer-view.h>
 #include <common/string-utils/format.h>
+#include <common/fd-tracker/fd-tracker.h>
 
 #include "backward-compatibility-group-by.h"
 #include "cmd.h"
@@ -179,6 +180,9 @@ struct health_app *health_relayd;
 
 struct sessiond_trace_chunk_registry *sessiond_trace_chunk_registry;
 
+/* Global fd tracker. */
+struct fd_tracker *the_fd_tracker;
+
 static struct option long_options[] = {
 	{ "control-port", 1, 0, 'C', },
 	{ "data-port", 1, 0, 'D', },
@@ -631,13 +635,9 @@ exit:
 
 static void print_global_objects(void)
 {
-	rcu_register_thread();
-
 	print_viewer_streams();
 	print_relay_streams();
 	print_sessions();
-
-	rcu_unregister_thread();
 }
 
 /*
@@ -670,6 +670,9 @@ static void relayd_cleanup(void)
 		sessiond_trace_chunk_registry_destroy(
 				sessiond_trace_chunk_registry);
 	}
+	if (the_fd_tracker) {
+		fd_tracker_destroy(the_fd_tracker);
+	}
 
 	uri_free(control_uri);
 	uri_free(data_uri);
@@ -678,6 +681,7 @@ static void relayd_cleanup(void)
 	if (tracing_group_name_override) {
 		free((void *) tracing_group_name);
 	}
+	fd_tracker_log(the_fd_tracker);
 }
 
 /*
@@ -3977,6 +3981,7 @@ static int create_relay_conn_pipe(void)
  */
 int main(int argc, char **argv)
 {
+	bool thread_is_rcu_registered = false;
 	int ret = 0, retval = 0;
 	void *status;
 
@@ -4071,6 +4076,21 @@ int main(int argc, char **argv)
 		goto exit_options;
 	}
 
+	/*
+	 * The RCU thread registration (and use, through the fd-tracker's
+	 * creation) is done after the daemonization to allow us to not
+	 * deal with liburcu's fork() management as the call RCU needs to
+	 * be restored.
+	 */
+	rcu_register_thread();
+	thread_is_rcu_registered = true;
+
+	the_fd_tracker = fd_tracker_create(lttng_opt_fd_cap);
+	if (!the_fd_tracker) {
+		retval = -1;
+		goto exit_options;
+	}
+
 	/* Initialize thread health monitoring */
 	health_relayd = health_app_create(NR_HEALTH_RELAYD_TYPES);
 	if (!health_relayd) {
@@ -4225,6 +4245,10 @@ exit_options:
 	/* Ensure all prior call_rcu are done. */
 	rcu_barrier();
 
+	if (thread_is_rcu_registered) {
+		rcu_unregister_thread();
+	}
+
 	if (!retval) {
 		exit(EXIT_SUCCESS);
 	} else {