| 1 | /* |
| 2 | * SPDX-License-Identifier: MIT |
| 3 | * |
| 4 | * Copyright (C) 2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 5 | * |
| 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. |
| 9 | */ |
| 10 | |
| 11 | #ifndef _LTTNG_UST_CONTEXT_PROVIDER_H |
| 12 | #define _LTTNG_UST_CONTEXT_PROVIDER_H |
| 13 | |
| 14 | #include <stddef.h> |
| 15 | #include <lttng/ust-events.h> |
| 16 | #include <urcu/hlist.h> |
| 17 | |
| 18 | #include "ust-dynamic-type.h" |
| 19 | |
| 20 | /* |
| 21 | * Context value |
| 22 | * |
| 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. |
| 28 | */ |
| 29 | |
| 30 | struct lttng_ust_ctx_value { |
| 31 | enum lttng_ust_dynamic_type sel; /* Type selector */ |
| 32 | union { |
| 33 | int64_t s64; |
| 34 | uint64_t u64; |
| 35 | const char *str; |
| 36 | double d; |
| 37 | } u; |
| 38 | }; |
| 39 | |
| 40 | /* |
| 41 | * Context field |
| 42 | * |
| 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 |
| 45 | * removed. |
| 46 | * |
| 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. |
| 50 | */ |
| 51 | |
| 52 | struct lttng_ust_ctx_field { |
| 53 | uint32_t struct_size; |
| 54 | void *priv; |
| 55 | |
| 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 | |
| 65 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 66 | }; |
| 67 | |
| 68 | /* |
| 69 | * All context fields for a given event/channel |
| 70 | * |
| 71 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 72 | * UST. Fields need to be only added at the end, never reordered, never |
| 73 | * removed. |
| 74 | * |
| 75 | * The field @struct_size should be used to determine the size of the |
| 76 | * structure. It should be queried before using additional fields added |
| 77 | * at the end of the structure. |
| 78 | */ |
| 79 | |
| 80 | struct lttng_ust_ctx { |
| 81 | uint32_t struct_size; |
| 82 | |
| 83 | struct lttng_ust_ctx_field **fields; |
| 84 | unsigned int nr_fields; |
| 85 | unsigned int allocated_fields; |
| 86 | unsigned int largest_align; |
| 87 | |
| 88 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 89 | }; |
| 90 | |
| 91 | /* |
| 92 | * Context provider |
| 93 | * |
| 94 | * IMPORTANT: this structure is part of the ABI between the probe and |
| 95 | * UST. Fields need to be only added at the end, never reordered, never |
| 96 | * removed. |
| 97 | * |
| 98 | * The field @struct_size should be used to determine the size of the |
| 99 | * structure. It should be queried before using additional fields added |
| 100 | * at the end of the structure. |
| 101 | */ |
| 102 | |
| 103 | struct lttng_ust_context_provider { |
| 104 | uint32_t struct_size; |
| 105 | |
| 106 | char *name; |
| 107 | size_t (*get_size)(struct lttng_ust_ctx_field *field, size_t offset); |
| 108 | void (*record)(struct lttng_ust_ctx_field *field, |
| 109 | struct lttng_ust_lib_ring_buffer_ctx *ctx, |
| 110 | struct lttng_channel *chan); |
| 111 | void (*get_value)(struct lttng_ust_ctx_field *field, |
| 112 | struct lttng_ust_ctx_value *value); |
| 113 | struct cds_hlist_node node; |
| 114 | |
| 115 | /* End of base ABI. Fields below should be used after checking struct_size. */ |
| 116 | }; |
| 117 | |
| 118 | int lttng_ust_context_provider_register(struct lttng_ust_context_provider *provider); |
| 119 | void lttng_ust_context_provider_unregister(struct lttng_ust_context_provider *provider); |
| 120 | |
| 121 | void lttng_ust_context_set_session_provider(const char *name, |
| 122 | size_t (*get_size)(struct lttng_ust_ctx_field *field, size_t offset), |
| 123 | void (*record)(struct lttng_ust_ctx_field *field, |
| 124 | struct lttng_ust_lib_ring_buffer_ctx *ctx, |
| 125 | struct lttng_channel *chan), |
| 126 | void (*get_value)(struct lttng_ust_ctx_field *field, |
| 127 | struct lttng_ust_ctx_value *value)); |
| 128 | |
| 129 | int lttng_ust_add_app_context_to_ctx_rcu(const char *name, struct lttng_ust_ctx **ctx); |
| 130 | int lttng_ust_context_set_provider_rcu(struct lttng_ust_ctx **_ctx, |
| 131 | const char *name, |
| 132 | size_t (*get_size)(struct lttng_ust_ctx_field *field, size_t offset), |
| 133 | void (*record)(struct lttng_ust_ctx_field *field, |
| 134 | struct lttng_ust_lib_ring_buffer_ctx *ctx, |
| 135 | struct lttng_channel *chan), |
| 136 | void (*get_value)(struct lttng_ust_ctx_field *field, |
| 137 | struct lttng_ust_ctx_value *value)); |
| 138 | |
| 139 | #endif /* _LTTNG_UST_CONTEXT_PROVIDER_H */ |