Implement consumer ring buffer position sampling

[lttng-tools.git] / src / bin / lttng-sessiond / kernel-consumer.c

diff --git a/src/bin/lttng-sessiond/kernel-consumer.c b/src/bin/lttng-sessiond/kernel-consumer.c
index f634cd362a74fd810622d8d49c28397c137b4a27..a65e1493c384ea75401266b019b56ab605ce7e89 100644 (file)
--- a/src/bin/lttng-sessiond/kernel-consumer.c
+++ b/src/bin/lttng-sessiond/kernel-consumer.c
@@ -15,20 +15,22 @@
  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
 #define _LGPL_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
 #include <common/common.h>
 #include <common/defaults.h>
+#include <common/compat/string.h>
 
 #include "consumer.h"
 #include "health-sessiond.h"
 #include "kernel-consumer.h"
+#include "notification-thread-commands.h"
+#include "session.h"
+#include "lttng-sessiond.h"
 
 static char *create_channel_path(struct consumer_output *consumer,
                uid_t uid, gid_t gid)
@@ -48,12 +50,16 @@ static char *create_channel_path(struct consumer_output *consumer,
                        PERROR("snprintf kernel channel path");
                        goto error;
                }
-               pathname = strndup(tmp_path, sizeof(tmp_path));
+               pathname = lttng_strndup(tmp_path, sizeof(tmp_path));
+               if (!pathname) {
+                       PERROR("lttng_strndup");
+                       goto error;
+               }
 
                /* Create directory */
                ret = run_as_mkdir_recursive(pathname, S_IRWXU | S_IRWXG, uid, gid);
                if (ret < 0) {
-                       if (ret != -EEXIST) {
+                       if (errno != EEXIST) {
                                ERR("Trace directory creation error");
                                goto error;
                        }
@@ -65,7 +71,11 @@ static char *create_channel_path(struct consumer_output *consumer,
                        PERROR("snprintf kernel metadata path");
                        goto error;
                }
-               pathname = strndup(tmp_path, sizeof(tmp_path));
+               pathname = lttng_strndup(tmp_path, sizeof(tmp_path));
+               if (!pathname) {
+                       PERROR("lttng_strndup");
+                       goto error;
+               }
                DBG3("Kernel network consumer subdir path: %s", pathname);
        }
 
@@ -80,43 +90,50 @@ error:
  * Sending a single channel to the consumer with command ADD_CHANNEL.
  */
 int kernel_consumer_add_channel(struct consumer_socket *sock,
-               struct ltt_kernel_channel *channel, struct ltt_kernel_session *session,
+               struct ltt_kernel_channel *channel,
+               struct ltt_kernel_session *ksession,
                unsigned int monitor)
 {
        int ret;
        char *pathname;
        struct lttcomm_consumer_msg lkm;
        struct consumer_output *consumer;
+       enum lttng_error_code status;
+       struct ltt_session *session;
+       struct lttng_channel_extended *channel_attr_extended;
 
        /* Safety net */
        assert(channel);
-       assert(session);
-       assert(session->consumer);
+       assert(ksession);
+       assert(ksession->consumer);
 
-       consumer = session->consumer;
+       consumer = ksession->consumer;
+       channel_attr_extended = (struct lttng_channel_extended *)
+                       channel->channel->attr.extended.ptr;
 
        DBG("Kernel consumer adding channel %s to kernel consumer",
                        channel->channel->name);
 
        if (monitor) {
-               pathname = create_channel_path(consumer, session->uid, session->gid);
-               if (!pathname) {
-                       ret = -1;
-                       goto error;
-               }
+               pathname = create_channel_path(consumer, ksession->uid,
+                               ksession->gid);
        } else {
                /* Empty path. */
                pathname = strdup("");
        }
+       if (!pathname) {
+               ret = -1;
+               goto error;
+       }
 
        /* Prep channel message structure */
        consumer_init_channel_comm_msg(&lkm,
                        LTTNG_CONSUMER_ADD_CHANNEL,
                        channel->fd,
-                       session->id,
+                       ksession->id,
                        pathname,
-                       session->uid,
-                       session->gid,
+                       ksession->uid,
+                       ksession->gid,
                        consumer->net_seq_index,
                        channel->channel->name,
                        channel->stream_count,
@@ -125,7 +142,8 @@ int kernel_consumer_add_channel(struct consumer_socket *sock,
                        channel->channel->attr.tracefile_size,
                        channel->channel->attr.tracefile_count,
                        monitor,
-                       channel->channel->attr.live_timer_interval);
+                       channel->channel->attr.live_timer_interval,
+                       channel_attr_extended->monitor_timer_interval);
 
        health_code_update();
 
@@ -135,7 +153,21 @@ int kernel_consumer_add_channel(struct consumer_socket *sock,
        }
 
        health_code_update();
+       rcu_read_lock();
+       session = session_find_by_id(ksession->id);
+       assert(session);
 
+       status = notification_thread_command_add_channel(
+                       notification_thread_handle, session->name,
+                       ksession->uid, ksession->gid,
+                       channel->channel->name, channel->fd,
+                       LTTNG_DOMAIN_KERNEL,
+                       channel->channel->attr.subbuf_size * channel->channel->attr.num_subbuf);
+       rcu_read_unlock();
+       if (status != LTTNG_OK) {
+               ret = -1;
+               goto error;
+       }
 error:
        free(pathname);
        return ret;
@@ -164,14 +196,14 @@ int kernel_consumer_add_metadata(struct consumer_socket *sock,
 
        if (monitor) {
                pathname = create_channel_path(consumer, session->uid, session->gid);
-               if (!pathname) {
-                       ret = -1;
-                       goto error;
-               }
        } else {
                /* Empty path. */
                pathname = strdup("");
        }
+       if (!pathname) {
+               ret = -1;
+               goto error;
+       }
 
        /* Prep channel message structure */
        consumer_init_channel_comm_msg(&lkm,
@@ -187,7 +219,7 @@ int kernel_consumer_add_metadata(struct consumer_socket *sock,
                        DEFAULT_KERNEL_CHANNEL_OUTPUT,
                        CONSUMER_CHANNEL_TYPE_METADATA,
                        0, 0,
-                       monitor, 0);
+                       monitor, 0, 0);
 
        health_code_update();
 
@@ -331,7 +363,7 @@ int kernel_consumer_send_channel_stream(struct consumer_socket *sock,
 
        /* Send streams */
        cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
-               if (!stream->fd) {
+               if (!stream->fd || stream->sent_to_consumer) {
                        continue;
                }
 
@@ -341,6 +373,7 @@ int kernel_consumer_send_channel_stream(struct consumer_socket *sock,
                if (ret < 0) {
                        goto error;
                }
+               stream->sent_to_consumer = true;
        }
 
 error: