sessiond: notification: receive incoming notifications from tracers

[lttng-tools.git] / src / bin / lttng-sessiond / notification-thread.c

diff --git a/src/bin/lttng-sessiond/notification-thread.c b/src/bin/lttng-sessiond/notification-thread.c
index 9b2cd5b96a9139ad9cea7e934b4e84770167d40c..1ba724337b67ee69a1856087a5c8b65c45a32cd8 100644 (file)
--- a/src/bin/lttng-sessiond/notification-thread.c
+++ b/src/bin/lttng-sessiond/notification-thread.c
@@ -28,6 +28,9 @@
 #include "health-sessiond.h"
 #include "thread.h"
 
+#include "kernel.h"
+#include <common/kernel-ctl/kernel-ctl.h>
+
 #include <urcu.h>
 #include <urcu/list.h>
 #include <urcu/rculfhash.h>
@@ -69,6 +72,7 @@ void notification_thread_handle_destroy(
                        PERROR("close kernel consumer channel monitoring pipe");
                }
        }
+
 end:
        free(handle);
 }
@@ -134,6 +138,7 @@ struct notification_thread_handle *notification_thread_handle_create(
        } else {
                handle->channel_monitoring_pipes.kernel_consumer = -1;
        }
+
 end:
        return handle;
 error:
@@ -366,6 +371,10 @@ void fini_thread_state(struct notification_thread_state *state)
                ret = cds_lfht_destroy(state->triggers_by_name_uid_ht, NULL);
                assert(!ret);
        }
+       if (state->trigger_tokens_ht) {
+               ret = cds_lfht_destroy(state->trigger_tokens_ht, NULL);
+               assert(!ret);
+       }
        /*
         * Must be destroyed after all channels have been destroyed.
         * See comment in struct lttng_session_trigger_list.
@@ -378,6 +387,9 @@ void fini_thread_state(struct notification_thread_state *state)
                notification_channel_socket_destroy(
                                state->notification_channel_socket);
        }
+
+       assert(cds_list_empty(&state->tracer_event_sources_list));
+
        if (state->executor) {
                action_executor_destroy(state->executor);
        }
@@ -486,6 +498,14 @@ int init_thread_state(struct notification_thread_handle *handle,
                goto error;
        }
 
+       state->trigger_tokens_ht = cds_lfht_new(DEFAULT_HT_SIZE,
+                       1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
+       if (!state->trigger_tokens_ht) {
+               goto error;
+       }
+
+       CDS_INIT_LIST_HEAD(&state->tracer_event_sources_list);
+
        state->executor = action_executor_create(handle);
        if (!state->executor) {
                goto error;
@@ -534,6 +554,59 @@ end:
        return ret;
 }
 
+static int handle_event_notification_pipe(int event_source_fd,
+               enum lttng_domain_type domain,
+               uint32_t revents,
+               struct notification_thread_state *state)
+{
+       int ret = 0;
+
+       if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+               ret = handle_notification_thread_remove_tracer_event_source_no_result(
+                               state, event_source_fd);
+               if (ret) {
+                       ERR("[notification-thread] Failed to remove event notification pipe from poll set: fd = %d",
+                                       event_source_fd);
+               }
+               goto end;
+       }
+
+       ret = handle_notification_thread_event_notification(
+                       state, event_source_fd, domain);
+       if (ret) {
+               ERR("[notification-thread] Event notification handling error occurred for fd: %d",
+                               event_source_fd);
+               ret = -1;
+               goto end;
+       }
+end:
+       return ret;
+}
+
+/*
+ * Return the event source domain type via parameter.
+ */
+static bool fd_is_event_notification_source(const struct notification_thread_state *state,
+               int fd,
+               enum lttng_domain_type *domain)
+{
+       struct notification_event_tracer_event_source_element *source_element;
+
+       assert(domain);
+
+       cds_list_for_each_entry(source_element,
+                       &state->tracer_event_sources_list, node) {
+               if (source_element->fd != fd) {
+                       continue;
+               }
+
+               *domain = source_element->domain;
+               return true;
+       }
+
+       return false;
+}
+
 /*
  * This thread services notification channel clients and commands received
  * from various lttng-sessiond components over a command queue.
@@ -544,6 +617,7 @@ void *thread_notification(void *data)
        int ret;
        struct notification_thread_handle *handle = data;
        struct notification_thread_state state;
+       enum lttng_domain_type domain;
 
        DBG("[notification-thread] Started notification thread");
 
@@ -621,6 +695,11 @@ void *thread_notification(void *data)
                                if (ret) {
                                        goto error;
                                }
+                       } else if (fd_is_event_notification_source(&state, fd, &domain)) {
+                               ret = handle_event_notification_pipe(fd, domain, revents, &state);
+                               if (ret) {
+                                       goto error;
+                               }
                        } else {
                                /* Activity on a client's socket. */
                                if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {