#include <stddef.h>
#include <lttng/ust-events.h>
-#include <urcu/hlist.h>
#include "ust-dynamic-type.h"
-struct lttng_ctx_value {
- enum lttng_ust_dynamic_type sel;
+struct lttng_ust_registered_context_provider;
+
+/*
+ * Context value
+ *
+ * IMPORTANT: this structure is part of the ABI between the probe and
+ * UST. Additional selectors may be added in the future, mapping to new
+ * union fields, which means the overall size of this structure may
+ * increase. This means this structure should never be nested within a
+ * public structure interface, nor embedded in an array.
+ */
+
+struct lttng_ust_ctx_value {
+ enum lttng_ust_dynamic_type sel; /* Type selector */
union {
int64_t s64;
uint64_t u64;
} u;
};
-struct lttng_perf_counter_field;
+/*
+ * Context provider
+ *
+ * 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.
+ */
-#define LTTNG_UST_CTX_FIELD_PADDING 40
-struct lttng_ctx_field {
- struct lttng_ust_event_field event_field;
- size_t (*get_size)(struct lttng_ctx_field *field, size_t offset);
- void (*record)(struct lttng_ctx_field *field,
- struct lttng_ust_lib_ring_buffer_ctx *ctx,
- struct lttng_channel *chan);
- void (*get_value)(struct lttng_ctx_field *field,
- struct lttng_ctx_value *value);
- union {
- struct lttng_perf_counter_field *perf_counter;
- char padding[LTTNG_UST_CTX_FIELD_PADDING];
- } u;
- void (*destroy)(struct lttng_ctx_field *field);
- char *field_name; /* Has ownership, dynamically allocated. */
-};
+struct lttng_ust_context_provider {
+ uint32_t struct_size;
-#define LTTNG_UST_CTX_PADDING 20
-struct lttng_ctx {
- struct lttng_ctx_field *fields;
- unsigned int nr_fields;
- unsigned int allocated_fields;
- unsigned int largest_align;
- char padding[LTTNG_UST_CTX_PADDING];
-};
+ const char *name;
+ size_t (*get_size)(void *priv, size_t offset);
+ void (*record)(void *priv, struct lttng_ust_lib_ring_buffer_ctx *ctx,
+ struct lttng_ust_channel_buffer *chan);
+ void (*get_value)(void *priv, struct lttng_ust_ctx_value *value);
+ void *priv;
-struct lttng_ust_context_provider {
- char *name;
- size_t (*get_size)(struct lttng_ctx_field *field, size_t offset);
- void (*record)(struct lttng_ctx_field *field,
- struct lttng_ust_lib_ring_buffer_ctx *ctx,
- struct lttng_channel *chan);
- void (*get_value)(struct lttng_ctx_field *field,
- struct lttng_ctx_value *value);
- struct cds_hlist_node node;
+ /* End of base ABI. Fields below should be used after checking struct_size. */
};
-int lttng_ust_context_provider_register(struct lttng_ust_context_provider *provider);
-void lttng_ust_context_provider_unregister(struct lttng_ust_context_provider *provider);
-
-void lttng_ust_context_set_session_provider(const char *name,
- size_t (*get_size)(struct lttng_ctx_field *field, size_t offset),
- void (*record)(struct lttng_ctx_field *field,
- struct lttng_ust_lib_ring_buffer_ctx *ctx,
- struct lttng_channel *chan),
- void (*get_value)(struct lttng_ctx_field *field,
- struct lttng_ctx_value *value));
+/*
+ * Returns an opaque pointer on success, which must be passed to
+ * lttng_ust_context_provider_unregister for unregistration. Returns
+ * NULL on error.
+ */
+struct lttng_ust_registered_context_provider *lttng_ust_context_provider_register(struct lttng_ust_context_provider *provider);
-int lttng_ust_add_app_context_to_ctx_rcu(const char *name, struct lttng_ctx **ctx);
-int lttng_ust_context_set_provider_rcu(struct lttng_ctx **_ctx,
- const char *name,
- size_t (*get_size)(struct lttng_ctx_field *field, size_t offset),
- void (*record)(struct lttng_ctx_field *field,
- struct lttng_ust_lib_ring_buffer_ctx *ctx,
- struct lttng_channel *chan),
- void (*get_value)(struct lttng_ctx_field *field,
- struct lttng_ctx_value *value));
+void lttng_ust_context_provider_unregister(struct lttng_ust_registered_context_provider *reg_provider);
#endif /* _LTTNG_UST_CONTEXT_PROVIDER_H */