Fix session list locking

[lttng-tools.git] / ltt-sessiond / main.c

diff --git a/ltt-sessiond/main.c b/ltt-sessiond/main.c
index 73f80599c06b3491acedb298fd7e1d37d4cd569c..8a808236878edbefdd468967386e57d6dc2d13f3 100644 (file)
--- a/ltt-sessiond/main.c
+++ b/ltt-sessiond/main.c
@@ -468,7 +468,7 @@ static int update_kernel_pollfd(void)
        DBG("Updating kernel_pollfd");
 
        /* Get the number of channel of all kernel session */
        DBG("Updating kernel_pollfd");
 
        /* Get the number of channel of all kernel session */

-       pthread_mutex_lock(&session_list_ptr->lock);
+       lock_session_list();

        cds_list_for_each_entry(session, &session_list_ptr->head, list) {
                lock_session(session);
                if (session->kernel_session == NULL) {
        cds_list_for_each_entry(session, &session_list_ptr->head, list) {
                lock_session(session);
                if (session->kernel_session == NULL) {


@@ -505,7 +505,7 @@ static int update_kernel_pollfd(void)
                }
                unlock_session(session);
        }
                }
                unlock_session(session);
        }

-       pthread_mutex_unlock(&session_list_ptr->lock);
+       unlock_session_list();

 
        /* Adding wake up pipe */
        kernel_pollfd[nb_fd - 2].fd = kernel_poll_pipe[0];
 
        /* Adding wake up pipe */
        kernel_pollfd[nb_fd - 2].fd = kernel_poll_pipe[0];


@@ -517,7 +517,7 @@ static int update_kernel_pollfd(void)
        return nb_fd;
 
 error:
        return nb_fd;
 
 error:

-       pthread_mutex_unlock(&session_list_ptr->lock);
+       unlock_session_list();

        return -1;
 }
 
        return -1;
 }
 


@@ -537,7 +537,7 @@ static int update_kernel_stream(int fd)
 
        DBG("Updating kernel streams for channel fd %d", fd);
 
 
        DBG("Updating kernel streams for channel fd %d", fd);
 

-       pthread_mutex_lock(&session_list_ptr->lock);
+       lock_session_list();

        cds_list_for_each_entry(session, &session_list_ptr->head, list) {
                lock_session(session);
                if (session->kernel_session == NULL) {
        cds_list_for_each_entry(session, &session_list_ptr->head, list) {
                lock_session(session);
                if (session->kernel_session == NULL) {


@@ -568,10 +568,10 @@ static int update_kernel_stream(int fd)
        }
 
 end:
        }
 
 end:

+       unlock_session_list();

        if (session) {
                unlock_session(session);
        }
        if (session) {
                unlock_session(session);
        }

-       pthread_mutex_unlock(&session_list_ptr->lock);

        return ret;
 }
 
        return ret;
 }
 


@@ -1227,6 +1227,30 @@ error:
        return ret;
 }
 
        return ret;
 }
 

+/*
+ * Using the session list, filled a lttng_session array to send back to the
+ * client for session listing.
+ *
+ * The session list lock MUST be acquired before calling this function. Use
+ * lock_session_list() and unlock_session_list().
+ */
+static void list_lttng_sessions(struct lttng_session *sessions)
+{
+       int i = 0;
+       struct ltt_session *session;
+
+       DBG("Getting all available session");
+       /*
+        * Iterate over session list and append data after the control struct in
+        * the buffer.
+        */
+       cds_list_for_each_entry(session, &session_list_ptr->head, list) {
+               strncpy(sessions[i].path, session->path, PATH_MAX);
+               strncpy(sessions[i].name, session->name, NAME_MAX);
+               i++;
+       }
+}
+

 /*
  *     process_client_msg
  *
 /*
  *     process_client_msg
  *


@@ -1938,20 +1962,23 @@ static int process_client_msg(struct command_ctx *cmd_ctx)
        */
        case LTTNG_LIST_SESSIONS:
        {
        */
        case LTTNG_LIST_SESSIONS:
        {

-               unsigned int session_count;
+               lock_session_list();

 
 

-               session_count = get_session_count();
-               if (session_count == 0) {
+               if (session_list_ptr->count == 0) {

                        ret = LTTCOMM_NO_SESSION;
                        goto error;
                }
 
                        ret = LTTCOMM_NO_SESSION;
                        goto error;
                }
 

-               ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) * session_count);
+               ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) *
+                               session_list_ptr->count);

                if (ret < 0) {
                        goto setup_error;
                }
 
                if (ret < 0) {
                        goto setup_error;
                }
 

-               get_lttng_session((struct lttng_session *)(cmd_ctx->llm->payload));
+               /* Filled the session array */
+               list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload));
+
+               unlock_session_list();

 
                ret = LTTCOMM_OK;
                break;
 
                ret = LTTCOMM_OK;
                break;