Add probe descriptor field to enum and event class

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

diff --git a/include/lttng/ust-events.h b/include/lttng/ust-events.h
index cae9e71a55ef1cecbc2ebbc9b3e06222e6ddbb98..6a918f4d2b98a9b1bf6f34d3cb2887c94f8a8a95 100644 (file)
--- a/include/lttng/ust-events.h
+++ b/include/lttng/ust-events.h
@@ -31,8 +31,13 @@ extern "C" {
  * Older tracepoint providers can always register to newer lttng-ust
  * library, but the opposite is rejected: a newer tracepoint provider is
  * rejected by an older lttng-ust library.
+ *
+ * LTTNG_UST_PROVIDER_MAJOR_OLDEST_COMPATIBLE is the floor value of
+ * oldest provider major version currently allowed, typically increased
+ * when LTTng-UST has an ABI-breaking soname bump.
  */
-#define LTTNG_UST_PROVIDER_MAJOR       2
+#define LTTNG_UST_PROVIDER_MAJOR                       3
+#define LTTNG_UST_PROVIDER_MAJOR_OLDEST_COMPATIBLE     3
 #define LTTNG_UST_PROVIDER_MINOR       0
 
 struct lttng_ust_channel_buffer;
@@ -193,7 +198,7 @@ struct lttng_ust_type_array {
 struct lttng_ust_type_sequence {
        struct lttng_ust_type_common parent;
        uint32_t struct_size;
-       const char *length_name;        /* Length field name. */
+       const char *length_name;        /* Length field name. If NULL, use previous field. */
        const struct lttng_ust_type_common *elem_type;
        unsigned int alignment;         /* Minimum alignment before elements. */
        enum lttng_ust_string_encoding encoding;
@@ -225,6 +230,7 @@ struct lttng_ust_enum_desc {
        const char *name;
        const struct lttng_ust_enum_entry * const *entries;
        unsigned int nr_entries;
+       const struct lttng_ust_probe_desc *probe_desc;
 
        /* End of base ABI. Fields below should be used after checking struct_size. */
 };
@@ -252,6 +258,29 @@ struct lttng_ust_event_field {
        /* End of base ABI. Fields below should be used after checking struct_size. */
 };
 
+/*
+ * Tracepoint class description
+ *
+ * IMPORTANT: this structure is part of the ABI between the probe and
+ * UST. Fields need to be only added at the end, never reordered, never
+ * removed.
+ *
+ * The field @struct_size should be used to determine the size of the
+ * structure. It should be queried before using additional fields added
+ * at the end of the structure.
+ */
+
+struct lttng_ust_tracepoint_class {
+       uint32_t struct_size;
+
+       const struct lttng_ust_event_field * const *fields;
+       size_t nr_fields;
+       void (*probe_callback)(void);
+       const char *signature;                          /* Argument types/names received */
+       const struct lttng_ust_probe_desc *probe_desc;
+
+       /* End of base ABI. Fields below should be used after checking struct_size. */
+};
 
 /*
  * IMPORTANT: this structure is part of the ABI between the probe and
@@ -267,11 +296,8 @@ struct lttng_ust_event_desc {
 
        const char *event_name;
        const struct lttng_ust_probe_desc *probe_desc;
-       void (*probe_callback)(void);
-       const struct lttng_ust_event_field * const *fields;     /* event payload */
-       unsigned int nr_fields;
+       const struct lttng_ust_tracepoint_class *tp_class;
        const int **loglevel;
-       const char *signature;                          /* Argument types/names received */
        const char **model_emf_uri;
 
        /* End of base ABI. Fields below should be used after checking struct_size. */