2 * SPDX-License-Identifier: MIT
4 * Copyright (C) 2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 * The context provider feature is part of the ABI and used by the Java jni
7 * interface. This header should be moved to the public header directory once
8 * some test code and documentation is written.
11 #ifndef _LTTNG_UST_CONTEXT_PROVIDER_H
12 #define _LTTNG_UST_CONTEXT_PROVIDER_H
15 #include <lttng/ust-events.h>
17 #include "common/dynamic-type.h"
19 struct lttng_ust_registered_context_provider
;
24 * IMPORTANT: this structure is part of the ABI between the probe and
25 * UST. Additional selectors may be added in the future, mapping to new
26 * union fields, which means the overall size of this structure may
27 * increase. This means this structure should never be nested within a
28 * public structure interface, nor embedded in an array.
31 struct lttng_ust_ctx_value
{
32 enum lttng_ust_dynamic_type sel
; /* Type selector */
44 * IMPORTANT: this structure is part of the ABI between the probe and
45 * UST. Fields need to be only added at the end, never reordered, never
48 * The field @struct_size should be used to determine the size of the
49 * structure. It should be queried before using additional fields added
50 * at the end of the structure.
53 struct lttng_ust_context_provider
{
57 size_t (*get_size
)(void *priv
, size_t offset
);
58 void (*record
)(void *priv
, struct lttng_ust_lib_ring_buffer_ctx
*ctx
,
59 struct lttng_ust_channel_buffer
*chan
);
60 void (*get_value
)(void *priv
, struct lttng_ust_ctx_value
*value
);
63 /* End of base ABI. Fields below should be used after checking struct_size. */
67 * Returns an opaque pointer on success, which must be passed to
68 * lttng_ust_context_provider_unregister for unregistration. Returns
71 struct lttng_ust_registered_context_provider
*lttng_ust_context_provider_register(struct lttng_ust_context_provider
*provider
);
73 void lttng_ust_context_provider_unregister(struct lttng_ust_registered_context_provider
*reg_provider
);
75 #endif /* _LTTNG_UST_CONTEXT_PROVIDER_H */