SoW-2019-0002: Dynamic Snapshot
[lttng-tools.git] / src / bin / lttng-sessiond / notification-thread.c
index 7dadb2c6748a7ae6738dad9294144407996a4d0d..a52756c5a387ea023ed8ad34f30ab2a4fb0a314f 100644 (file)
@@ -29,6 +29,9 @@
 #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>
@@ -70,14 +73,27 @@ void notification_thread_handle_destroy(
                        PERROR("close kernel consumer channel monitoring pipe");
                }
        }
+
+       /* TODO: refactor this if needed. Lifetime of the kernel notification
+        * event source.
+        * event_trigger_sources.kernel_tracer is owned by the main thread and
+        * is closed at this point.
+        */
+       handle->event_trigger_sources.kernel_tracer = -1;
 end:
        free(handle);
 }
 
+/*
+ * TODO: refactor this if needed. Lifetime of the kernel notification event source.
+ * The kernel_notification_monitor_fd ownwership remain to the main thread.
+ * This is because we need to close this fd before removing the modules.
+ */
 struct notification_thread_handle *notification_thread_handle_create(
                struct lttng_pipe *ust32_channel_monitor_pipe,
                struct lttng_pipe *ust64_channel_monitor_pipe,
-               struct lttng_pipe *kernel_channel_monitor_pipe)
+               struct lttng_pipe *kernel_channel_monitor_pipe,
+               int kernel_notification_monitor_fd)
 {
        int ret;
        struct notification_thread_handle *handle;
@@ -88,6 +104,8 @@ struct notification_thread_handle *notification_thread_handle_create(
                goto end;
        }
 
+       handle->event_trigger_sources.kernel_tracer = -1;
+
        sem_init(&handle->ready, 0, 0);
 
        event_pipe = lttng_pipe_open(FD_CLOEXEC);
@@ -135,6 +153,14 @@ struct notification_thread_handle *notification_thread_handle_create(
        } else {
                handle->channel_monitoring_pipes.kernel_consumer = -1;
        }
+
+       handle->event_trigger_sources.kernel_tracer = kernel_notification_monitor_fd;
+
+       CDS_INIT_LIST_HEAD(&handle->event_trigger_sources.list);
+       ret = pthread_mutex_init(&handle->event_trigger_sources.lock, NULL);
+       if (ret) {
+               goto error;
+       }
 end:
        return handle;
 error:
@@ -266,14 +292,15 @@ int init_poll_set(struct lttng_poll_event *poll_set,
        int ret;
 
        /*
-        * Create pollset with size 5:
+        * Create pollset with size 6:
         *      - notification channel socket (listen for new connections),
         *      - command queue event fd (internal sessiond commands),
         *      - consumerd (32-bit user space) channel monitor pipe,
         *      - consumerd (64-bit user space) channel monitor pipe,
         *      - consumerd (kernel) channel monitor pipe.
+        *      - kernel trigger event pipe,
         */
-       ret = lttng_poll_create(poll_set, 5, LTTNG_CLOEXEC);
+       ret = lttng_poll_create(poll_set, 6, LTTNG_CLOEXEC);
        if (ret < 0) {
                goto end;
        }
@@ -305,7 +332,7 @@ int init_poll_set(struct lttng_poll_event *poll_set,
                goto error;
        }
        if (handle->channel_monitoring_pipes.kernel_consumer < 0) {
-               goto end;
+               goto skip_kernel_consumer;
        }
        ret = lttng_poll_add(poll_set,
                        handle->channel_monitoring_pipes.kernel_consumer,
@@ -314,6 +341,19 @@ int init_poll_set(struct lttng_poll_event *poll_set,
                ERR("[notification-thread] Failed to add kernel channel monitoring pipe fd to pollset");
                goto error;
        }
+
+skip_kernel_consumer:
+       if (handle->event_trigger_sources.kernel_tracer < 0) {
+               goto end;
+       }
+
+       ret = lttng_poll_add(poll_set,
+                       handle->event_trigger_sources.kernel_tracer,
+                       LPOLLIN | LPOLLERR);
+       if (ret < 0) {
+               ERR("[notification-thread] Failed to add kernel trigger notification monitoring pipe fd to pollset");
+               goto error;
+       }
 end:
        return ret;
 error:
@@ -332,6 +372,10 @@ void fini_thread_state(struct notification_thread_state *state)
                ret = cds_lfht_destroy(state->client_socket_ht, NULL);
                assert(!ret);
        }
+       if (state->client_id_ht) {
+               ret = cds_lfht_destroy(state->client_id_ht, NULL);
+               assert(!ret);
+       }
        if (state->triggers_ht) {
                ret = handle_notification_thread_trigger_unregister_all(state);
                assert(!ret);
@@ -359,6 +403,14 @@ void fini_thread_state(struct notification_thread_state *state)
                ret = cds_lfht_destroy(state->sessions_ht, NULL);
                assert(!ret);
        }
+       if (state->trigger_tokens_ht) {
+               ret = cds_lfht_destroy(state->trigger_tokens_ht, NULL);
+               assert(!ret);
+       }
+       if (state->triggers_by_name_ht) {
+               ret = cds_lfht_destroy(state->triggers_by_name_ht, NULL);
+               assert(!ret);
+       }
        /*
         * Must be destroyed after all channels have been destroyed.
         * See comment in struct lttng_session_trigger_list.
@@ -371,6 +423,9 @@ void fini_thread_state(struct notification_thread_state *state)
                notification_channel_socket_destroy(
                                state->notification_channel_socket);
        }
+       if (state->executor) {
+               action_executor_destroy(state->executor);
+       }
        lttng_poll_clean(&state->events);
 }
 
@@ -397,6 +452,7 @@ int init_thread_state(struct notification_thread_handle *handle,
 
        memset(state, 0, sizeof(*state));
        state->notification_channel_socket = -1;
+       state->trigger_id.token_generator = 1;
        lttng_poll_init(&state->events);
 
        ret = notification_channel_socket_create();
@@ -424,6 +480,12 @@ int init_thread_state(struct notification_thread_handle *handle,
                goto error;
        }
 
+       state->client_id_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
+                       CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
+       if (!state->client_id_ht) {
+               goto error;
+       }
+
        state->channel_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
                        CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
        if (!state->channel_triggers_ht) {
@@ -463,6 +525,20 @@ int init_thread_state(struct notification_thread_handle *handle,
        if (!state->triggers_ht) {
                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;
+       }
+       state->triggers_by_name_ht = cds_lfht_new(DEFAULT_HT_SIZE,
+                       1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
+       if (!state->triggers_by_name_ht) {
+               goto error;
+       }
+       state->executor = action_executor_create(handle);
+       if (!state->executor) {
+               goto error;
+       }
        mark_thread_as_ready(handle);
 end:
        return 0;
@@ -507,6 +583,54 @@ end:
        return ret;
 }
 
+static int handle_trigger_event_pipe(int fd,
+               uint32_t revents,
+               struct notification_thread_handle *handle,
+               struct notification_thread_state *state)
+{
+       int ret = 0;
+       enum lttng_domain_type domain;
+
+       if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+               ret = lttng_poll_del(&state->events, fd);
+               if (ret) {
+                       ERR("[notification-thread] Failed to remove event monitoring pipe from poll set");
+               }
+               goto end;
+       }
+
+       if (fd == handle->event_trigger_sources.kernel_tracer) {
+               domain = LTTNG_DOMAIN_KERNEL;
+       } else {
+               domain = LTTNG_DOMAIN_UST;
+       }
+
+       ret = handle_notification_thread_event(state, fd, domain);
+       if (ret) {
+               ERR("[notification-thread] Event sample handling error occurred for fd: %d", fd);
+               ret = -1;
+               goto end;
+       }
+end:
+       return ret;
+}
+
+static bool fd_is_event_source(struct notification_thread_handle *handle, int fd)
+{
+       struct notification_event_trigger_source_element *source_element, *tmp;
+       cds_list_for_each_entry_safe(source_element, tmp,
+                       &handle->event_trigger_sources.list, node) {
+               if (source_element->fd != fd) {
+                       continue;
+               }
+               return true;
+       }
+       if (fd == handle->event_trigger_sources.kernel_tracer) {
+               return true;
+       }
+       return false;
+}
+
 /*
  * This thread services notification channel clients and commands received
  * from various lttng-sessiond components over a command queue.
@@ -594,6 +718,11 @@ void *thread_notification(void *data)
                                if (ret) {
                                        goto error;
                                }
+                       } else if (fd_is_event_source(handle, fd)) {
+                               ret = handle_trigger_event_pipe(fd, revents, handle, &state);
+                               if (ret) {
+                                       goto error;
+                               }
                        } else {
                                /* Activity on a client's socket. */
                                if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
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