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 8b903680a7e9bf48d148a736d4f4e726d1860ba2..4fc35dc0f1881e90d05a6912d86e2ace525d0cbb 100644 (file)
--- 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 748083ddfa65e145a6ebde0a98ea9575db35ce86..fc68c513fcebd17be91be9702b2aca2c7f4be861 100644 (file)
--- 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 07e7a012245d5fa0d36fd919f40d00c380070be1..f1f03d1bd36c90c7feefb9f417d5748f8cd10c4f 100644 (file)
--- 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 {