Implement event notifier

[deliverable/lttng-ust.git] / include / lttng / ust-events.h

diff --git a/include/lttng/ust-events.h b/include/lttng/ust-events.h
index 1e359b004791d9225fbbb15cff33e56b392ca854..d89ddea6147a5659b694af6b53d11dba71861a85 100644 (file)
--- a/include/lttng/ust-events.h
+++ b/include/lttng/ust-events.h
@@ -360,6 +360,7 @@ struct lttng_event_desc {
        union {
                struct {
                        const char **model_emf_uri;
+                       void (*event_notifier_callback)(void);
                } ext;
                char padding[LTTNG_UST_EVENT_DESC_PADDING];
        } u;
@@ -446,14 +447,20 @@ struct lttng_bytecode_runtime {
        int link_failed;
        struct cds_list_head node;      /* list of bytecode runtime in event */
        /*
-        * Pointer to a `struct lttng_session`-owned and URCU-protected
-        * pointer.
+        * Pointer to a URCU-protected pointer owned by an `struct
+        * lttng_session`or `struct lttng_event_notifier_group`.
         */
        struct lttng_ctx **pctx;
 };
 
 /*
- * Objects in a linked-list of enablers, owned by an event.
+ * Objects in a linked-list of enablers, owned by an event or event_notifier.
+ * This is used because an event (or a event_notifier) can be enabled by more
+ * than one enabler and we want a quick way to iterate over all enablers of an
+ * object.
+ *
+ * For example, event rules "my_app:a*" and "my_app:ab*" will both match the
+ * event with the name "my_app:abc".
  */
 struct lttng_enabler_ref {
        struct cds_list_head node;              /* enabler ref list */
@@ -492,6 +499,19 @@ struct lttng_event {
        int registered;                 /* has reg'd tracepoint probe */
 };
 
+struct lttng_event_notifier {
+       uint64_t user_token;
+       int enabled;
+       int registered;                 /* has reg'd tracepoint probe */
+       struct cds_list_head filter_bytecode_runtime_head;
+       int has_enablers_without_bytecode;
+       struct cds_list_head enablers_ref_head;
+       const struct lttng_event_desc *desc;
+       struct cds_hlist_node hlist;    /* hashtable of event_notifiers */
+       struct cds_list_head node;      /* event_notifier list in session */
+       struct lttng_event_notifier_group *group; /* weak ref */
+};
+
 struct lttng_enum {
        const struct lttng_enum_desc *desc;
        struct lttng_session *session;
@@ -600,6 +620,12 @@ struct lttng_ust_event_ht {
        struct cds_hlist_head table[LTTNG_UST_EVENT_HT_SIZE];
 };
 
+#define LTTNG_UST_EVENT_NOTIFIER_HT_BITS               12
+#define LTTNG_UST_EVENT_NOTIFIER_HT_SIZE               (1U << LTTNG_UST_EVENT_NOTIFIER_HT_BITS)
+struct lttng_ust_event_notifier_ht {
+       struct cds_hlist_head table[LTTNG_UST_EVENT_NOTIFIER_HT_SIZE];
+};
+
 #define LTTNG_UST_ENUM_HT_BITS         12
 #define LTTNG_UST_ENUM_HT_SIZE         (1U << LTTNG_UST_ENUM_HT_BITS)
 
@@ -640,6 +666,17 @@ struct lttng_session {
        struct lttng_ctx *ctx;                  /* contexts for filters. */
 };
 
+struct lttng_event_notifier_group {
+       int objd;
+       void *owner;
+       int notification_fd;
+       struct cds_list_head node;              /* Event notifier group handle list */
+       struct cds_list_head enablers_head;
+       struct cds_list_head event_notifiers_head;      /* list of event_notifiers */
+       struct lttng_ust_event_notifier_ht event_notifiers_ht; /* hashtable of event_notifiers */
+       struct lttng_ctx *ctx;                  /* contexts for filters. */
+};
+
 struct lttng_transport {
        char *name;
        struct cds_list_head node;
@@ -653,6 +690,9 @@ int lttng_session_disable(struct lttng_session *session);
 int lttng_session_statedump(struct lttng_session *session);
 void lttng_session_destroy(struct lttng_session *session);
 
+void lttng_event_notifier_notification_send(
+               struct lttng_event_notifier *event_notifier);
+
 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
                                       const char *transport_name,
                                       void *buf_addr,