relayd: track stdio output file descriptors
[lttng-tools.git] / src / bin / lttng-relayd / main.c
index f61f1f13e69ce72eedfc53d3a1941951ae50041c..16bfccbfa0c982cd3c7fcd33c0ed1ea0999369cf 100644 (file)
@@ -63,6 +63,8 @@
 #include <common/dynamic-buffer.h>
 #include <common/buffer-view.h>
 #include <common/string-utils/format.h>
+#include <common/fd-tracker/fd-tracker.h>
+#include <common/fd-tracker/utils.h>
 
 #include "backward-compatibility-group-by.h"
 #include "cmd.h"
@@ -179,6 +181,9 @@ 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 +636,9 @@ exit:
 
 static void print_global_objects(void)
 {
-       rcu_register_thread();
-
        print_viewer_streams();
        print_relay_streams();
        print_sessions();
-
-       rcu_unregister_thread();
 }
 
 /*
@@ -659,8 +660,30 @@ static void relayd_cleanup(void)
        free(opt_output_path);
        free(opt_working_directory);
 
+       if (health_relayd) {
+               health_app_destroy(health_relayd);
+       }
        /* Close thread quit pipes */
-       utils_close_pipe(thread_quit_pipe);
+       if (health_quit_pipe[0] != -1) {
+               (void) fd_tracker_util_pipe_close(
+                               the_fd_tracker, health_quit_pipe);
+       }
+       if (thread_quit_pipe[0] != -1) {
+               (void) fd_tracker_util_pipe_close(
+                               the_fd_tracker, thread_quit_pipe);
+       }
+       if (sessiond_trace_chunk_registry) {
+               sessiond_trace_chunk_registry_destroy(
+                               sessiond_trace_chunk_registry);
+       }
+       if (the_fd_tracker) {
+               untrack_stdio();
+               /*
+                * fd_tracker_destroy() will log the contents of the fd-tracker
+                * if a leak is detected.
+                */
+               fd_tracker_destroy(the_fd_tracker);
+       }
 
        uri_free(control_uri);
        uri_free(data_uri);
@@ -822,17 +845,26 @@ void lttng_relay_notify_ready(void)
  */
 static int init_thread_quit_pipe(void)
 {
-       int ret;
-
-       ret = utils_create_pipe_cloexec(thread_quit_pipe);
+       return fd_tracker_util_pipe_open_cloexec(
+                       the_fd_tracker, "Quit pipe", thread_quit_pipe);
+}
 
-       return ret;
+/*
+ * Init health quit pipe.
+ *
+ * Return -1 on error or 0 if all pipes are created.
+ */
+static int init_health_quit_pipe(void)
+{
+       return fd_tracker_util_pipe_open_cloexec(the_fd_tracker,
+                       "Health quit pipe", health_quit_pipe);
 }
 
 /*
  * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
  */
-static int create_thread_poll_set(struct lttng_poll_event *events, int size)
+static int create_named_thread_poll_set(struct lttng_poll_event *events,
+               int size, const char *name)
 {
        int ret;
 
@@ -841,10 +873,8 @@ static int create_thread_poll_set(struct lttng_poll_event *events, int size)
                goto error;
        }
 
-       ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
-       if (ret < 0) {
-               goto error;
-       }
+       ret = fd_tracker_util_poll_create(the_fd_tracker,
+                       name, events, 1, LTTNG_CLOEXEC);
 
        /* Add quit pipe */
        ret = lttng_poll_add(events, thread_quit_pipe[0], LPOLLIN | LPOLLERR);
@@ -943,7 +973,7 @@ static void *relay_thread_listener(void *data)
         * Pass 3 as size here for the thread quit pipe, control and
         * data socket.
         */
-       ret = create_thread_poll_set(&events, 3);
+       ret = create_named_thread_poll_set(&events, 3, "Listener thread epoll");
        if (ret < 0) {
                goto error_create_poll;
        }
@@ -1077,7 +1107,7 @@ exit:
 error:
 error_poll_add:
 error_testpoint:
-       lttng_poll_clean(&events);
+       (void) fd_tracker_util_poll_clean(the_fd_tracker, &events);
 error_create_poll:
        if (data_sock->fd >= 0) {
                ret = data_sock->ops->close(data_sock);
@@ -3660,7 +3690,7 @@ static void *relay_thread_worker(void *data)
                goto relay_connections_ht_error;
        }
 
-       ret = create_thread_poll_set(&events, 2);
+       ret = create_named_thread_poll_set(&events, 2, "Worker thread epoll");
        if (ret < 0) {
                goto error_poll_create;
        }
@@ -3929,12 +3959,13 @@ error:
        }
        rcu_read_unlock();
 
-       lttng_poll_clean(&events);
+       (void) fd_tracker_util_poll_clean(the_fd_tracker, &events);
 error_poll_create:
        lttng_ht_destroy(relay_connections_ht);
 relay_connections_ht_error:
        /* Close relay conn pipes */
-       utils_close_pipe(relay_conn_pipe);
+       (void) fd_tracker_util_pipe_close(the_fd_tracker,
+                       relay_conn_pipe);
        if (err) {
                DBG("Thread exited with error");
        }
@@ -3956,11 +3987,41 @@ error_testpoint:
  */
 static int create_relay_conn_pipe(void)
 {
-       int ret;
+       return fd_tracker_util_pipe_open_cloexec(the_fd_tracker,
+                       "Relayd connection pipe", relay_conn_pipe);
+}
+
+static int stdio_open(void *data, int *fds)
+{
+       fds[0] = fileno(stdout);
+       fds[1] = fileno(stderr);
+       return 0;
+}
 
-       ret = utils_create_pipe_cloexec(relay_conn_pipe);
+static int noop_close(void *data, int *fds)
+{
+       return 0;
+}
 
-       return ret;
+static int track_stdio(void)
+{
+       int fds[2];
+       const char *names[] = { "stdout", "stderr" };
+
+       return fd_tracker_open_unsuspendable_fd(the_fd_tracker, fds,
+                       names, 2, stdio_open, NULL);
+}
+
+static void untrack_stdio(void)
+{
+       int fds[] = { fileno(stdout), fileno(stderr) };
+
+       /*
+        * noop_close is used since we don't really want to close
+        * the stdio output fds; we merely want to stop tracking them.
+        */
+       (void) fd_tracker_close_unsuspendable_fd(the_fd_tracker,
+                       fds, 2, noop_close, NULL);
 }
 
 /*
@@ -3968,6 +4029,7 @@ 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;
 
@@ -4028,23 +4090,12 @@ int main(int argc, char **argv)
 
        /* Daemonize */
        if (opt_daemon || opt_background) {
-               int i;
-
                ret = lttng_daemonize(&child_ppid, &recv_child_signal,
                        !opt_background);
                if (ret < 0) {
                        retval = -1;
                        goto exit_options;
                }
-
-               /*
-                * We are in the child. Make sure all other file
-                * descriptors are closed, in case we are called with
-                * more opened file descriptors than the standard ones.
-                */
-               for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) {
-                       (void) close(i);
-               }
        }
 
        if (opt_working_directory) {
@@ -4059,7 +4110,28 @@ int main(int argc, char **argv)
        if (!sessiond_trace_chunk_registry) {
                ERR("Failed to initialize session daemon trace chunk registry");
                retval = -1;
-               goto exit_sessiond_trace_chunk_registry;
+               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;
+       }
+
+       ret = track_stdio();
+       if (ret) {
+               retval = -1;
+               goto exit_options;
        }
 
        /* Initialize thread health monitoring */
@@ -4067,19 +4139,19 @@ int main(int argc, char **argv)
        if (!health_relayd) {
                PERROR("health_app_create error");
                retval = -1;
-               goto exit_health_app_create;
+               goto exit_options;
        }
 
        /* Create thread quit pipe */
        if (init_thread_quit_pipe()) {
                retval = -1;
-               goto exit_init_data;
+               goto exit_options;
        }
 
        /* Setup the thread apps communication pipe. */
        if (create_relay_conn_pipe()) {
                retval = -1;
-               goto exit_init_data;
+               goto exit_options;
        }
 
        /* Init relay command queue. */
@@ -4093,27 +4165,27 @@ int main(int argc, char **argv)
        sessions_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
        if (!sessions_ht) {
                retval = -1;
-               goto exit_init_data;
+               goto exit_options;
        }
 
        /* tables of streams indexed by stream ID */
        relay_streams_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
        if (!relay_streams_ht) {
                retval = -1;
-               goto exit_init_data;
+               goto exit_options;
        }
 
        /* tables of streams indexed by stream ID */
        viewer_streams_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
        if (!viewer_streams_ht) {
                retval = -1;
-               goto exit_init_data;
+               goto exit_options;
        }
 
-       ret = utils_create_pipe(health_quit_pipe);
+       ret = init_health_quit_pipe();
        if (ret) {
                retval = -1;
-               goto exit_health_quit_pipe;
+               goto exit_options;
        }
 
        /* Create thread to manage the client socket */
@@ -4123,7 +4195,7 @@ int main(int argc, char **argv)
                errno = ret;
                PERROR("pthread_create health");
                retval = -1;
-               goto exit_health_thread;
+               goto exit_options;
        }
 
        /* Setup the dispatcher thread */
@@ -4204,16 +4276,6 @@ exit_dispatcher_thread:
                PERROR("pthread_join health_thread");
                retval = -1;
        }
-exit_health_thread:
-
-       utils_close_pipe(health_quit_pipe);
-exit_health_quit_pipe:
-
-exit_init_data:
-       health_app_destroy(health_relayd);
-       sessiond_trace_chunk_registry_destroy(sessiond_trace_chunk_registry);
-exit_health_app_create:
-exit_sessiond_trace_chunk_registry:
 exit_options:
        /*
         * Wait for all pending call_rcu work to complete before tearing
@@ -4226,6 +4288,10 @@ 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 {
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