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>
16 #include <urcu/hlist.h>
18 #include "ust-dynamic-type.h"
23 * IMPORTANT: this structure is part of the ABI between the probe and
24 * UST. Additional selectors may be added in the future, mapping to new
25 * union fields, which means the overall size of this structure may
26 * increase. This means this structure should never be nested within a
27 * public structure interface, nor embedded in an array.
30 struct lttng_ust_ctx_value
{
31 enum lttng_ust_dynamic_type sel
; /* Type selector */
43 * IMPORTANT: this structure is part of the ABI between the probe and
44 * UST. Fields need to be only added at the end, never reordered, never
47 * The field @struct_size should be used to determine the size of the
48 * structure. It should be queried before using additional fields added
49 * at the end of the structure.
52 struct lttng_ust_ctx_field
{
56 struct lttng_ust_event_field
*event_field
;
57 size_t (*get_size
)(struct lttng_ust_ctx_field
*field
, size_t offset
);
58 void (*record
)(struct lttng_ust_ctx_field
*field
,
59 struct lttng_ust_lib_ring_buffer_ctx
*ctx
,
60 struct lttng_channel
*chan
);
61 void (*get_value
)(struct lttng_ust_ctx_field
*field
,
62 struct lttng_ust_ctx_value
*value
);
63 void (*destroy
)(struct lttng_ust_ctx_field
*field
);
64 char *field_name
; /* Has ownership, dynamically allocated. */
66 /* End of base ABI. Fields below should be used after checking struct_size. */
70 * All context fields for a given event/channel
72 * IMPORTANT: this structure is part of the ABI between the probe and
73 * UST. Fields need to be only added at the end, never reordered, never
76 * The field @struct_size should be used to determine the size of the
77 * structure. It should be queried before using additional fields added
78 * at the end of the structure.
81 struct lttng_ust_ctx
{
84 struct lttng_ust_ctx_field
**fields
;
85 unsigned int nr_fields
;
86 unsigned int allocated_fields
;
87 unsigned int largest_align
;
89 /* End of base ABI. Fields below should be used after checking struct_size. */
95 * IMPORTANT: this structure is part of the ABI between the probe and
96 * UST. Fields need to be only added at the end, never reordered, never
99 * The field @struct_size should be used to determine the size of the
100 * structure. It should be queried before using additional fields added
101 * at the end of the structure.
104 struct lttng_ust_context_provider
{
105 uint32_t struct_size
;
108 size_t (*get_size
)(struct lttng_ust_ctx_field
*field
, size_t offset
);
109 void (*record
)(struct lttng_ust_ctx_field
*field
,
110 struct lttng_ust_lib_ring_buffer_ctx
*ctx
,
111 struct lttng_channel
*chan
);
112 void (*get_value
)(struct lttng_ust_ctx_field
*field
,
113 struct lttng_ust_ctx_value
*value
);
114 struct cds_hlist_node node
;
116 /* End of base ABI. Fields below should be used after checking struct_size. */
119 int lttng_ust_context_provider_register(struct lttng_ust_context_provider
*provider
);
120 void lttng_ust_context_provider_unregister(struct lttng_ust_context_provider
*provider
);
122 void lttng_ust_context_set_session_provider(const char *name
,
123 size_t (*get_size
)(struct lttng_ust_ctx_field
*field
, size_t offset
),
124 void (*record
)(struct lttng_ust_ctx_field
*field
,
125 struct lttng_ust_lib_ring_buffer_ctx
*ctx
,
126 struct lttng_channel
*chan
),
127 void (*get_value
)(struct lttng_ust_ctx_field
*field
,
128 struct lttng_ust_ctx_value
*value
));
130 int lttng_ust_add_app_context_to_ctx_rcu(const char *name
, struct lttng_ust_ctx
**ctx
);
131 int lttng_ust_context_set_provider_rcu(struct lttng_ust_ctx
**_ctx
,
133 size_t (*get_size
)(struct lttng_ust_ctx_field
*field
, size_t offset
),
134 void (*record
)(struct lttng_ust_ctx_field
*field
,
135 struct lttng_ust_lib_ring_buffer_ctx
*ctx
,
136 struct lttng_channel
*chan
),
137 void (*get_value
)(struct lttng_ust_ctx_field
*field
,
138 struct lttng_ust_ctx_value
*value
));
140 #endif /* _LTTNG_UST_CONTEXT_PROVIDER_H */