Fix: sessiond: size-based notification occasionally not triggered

[lttng-tools.git] / src / bin / lttng-sessiond / rotate.cpp

diff --git a/src/bin/lttng-sessiond/rotate.cpp b/src/bin/lttng-sessiond/rotate.cpp
index cc857544390ea24674b8da75cf035fc59a0fd430..56a61fe2a35924430ce5dfe6dec548cca458fa87 100644 (file)
--- a/src/bin/lttng-sessiond/rotate.cpp
+++ b/src/bin/lttng-sessiond/rotate.cpp
@@ -49,6 +49,7 @@ int subscribe_session_consumed_size_rotation(
        int ret;
        enum lttng_condition_status condition_status;
        enum lttng_notification_channel_status nc_status;
+       const uint64_t eventfd_increment_value = 1;
        struct lttng_condition *rotate_condition = nullptr;
        struct lttng_action *notify_action = nullptr;
        const struct lttng_credentials session_creds = {
@@ -108,6 +109,15 @@ int subscribe_session_consumed_size_rotation(
                goto end;
        }
 
+       ret = lttng_write(rotate_notification_channel_subscription_change_eventfd,
+                         &eventfd_increment_value,
+                         sizeof(eventfd_increment_value));
+       if (ret != sizeof(eventfd_increment_value)) {
+               PERROR("Failed to wake up rotation thread as writing to the rotation thread notification channel subscription change eventfd failed");
+               ret = -1;
+               goto end;
+       }
+
        ret = notification_thread_command_register_trigger(
                notification_thread_handle, session->rotate_trigger, true);
        if (ret < 0 && ret != -LTTNG_ERR_TRIGGER_EXISTS) {
@@ -132,6 +142,7 @@ int unsubscribe_session_consumed_size_rotation(
 {
        int ret = 0;
        enum lttng_notification_channel_status status;
+       const uint64_t eventfd_increment_value = 1;
 
        LTTNG_ASSERT(session->rotate_trigger);
        status = lttng_notification_channel_unsubscribe(
@@ -143,6 +154,15 @@ int unsubscribe_session_consumed_size_rotation(
                goto end;
        }
 
+       ret = lttng_write(rotate_notification_channel_subscription_change_eventfd,
+                         &eventfd_increment_value,
+                         sizeof(eventfd_increment_value));
+       if (ret != sizeof(eventfd_increment_value)) {
+               PERROR("Failed to wake up rotation thread as writing to the rotation thread notification channel subscription change eventfd failed");
+               ret = -1;
+               goto end;
+       }
+
        ret = notification_thread_command_unregister_trigger(notification_thread_handle,
                                                             session->rotate_trigger);
        if (ret != LTTNG_OK) {