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2c5ff4e4 | 1 | /* |
ab5be9fa | 2 | * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
2c5ff4e4 | 3 | * |
ab5be9fa | 4 | * SPDX-License-Identifier: LGPL-2.1-only |
2c5ff4e4 | 5 | * |
2c5ff4e4 JG |
6 | */ |
7 | ||
8 | #ifndef LTTNG_TRACE_CHUNK_REGISTRY_H | |
9 | #define LTTNG_TRACE_CHUNK_REGISTRY_H | |
10 | ||
11 | #include <stddef.h> | |
12 | #include <stdint.h> | |
13 | #include <stdbool.h> | |
14 | #include <common/macros.h> | |
15 | #include <common/trace-chunk.h> | |
16 | ||
17 | struct lttng_trace_chunk_registry; | |
18 | ||
19 | /* | |
20 | * Create an lttng_trace_chunk registry. | |
21 | * | |
22 | * A trace chunk registry maintains an association between a | |
23 | * (session_id, chunk_id) tuple and a trace chunk object. The chunk_id can | |
24 | * be "unset" in the case of an anonymous trace chunk. | |
25 | * | |
26 | * Note that a trace chunk registry holds no ownership of its trace | |
27 | * chunks. Trace chunks are unpublished when their last reference is released. | |
28 | * See the documentation of lttng_trace_chunk. | |
29 | * | |
30 | * Returns a trace chunk registry on success, NULL on error. | |
31 | * | |
32 | * Note that a trace chunk registry may only be accessed by an RCU thread. | |
33 | */ | |
2c5ff4e4 JG |
34 | struct lttng_trace_chunk_registry *lttng_trace_chunk_registry_create(void); |
35 | ||
36 | /* | |
37 | * Destroy an lttng trace chunk registry. The registry must be emptied | |
38 | * (i.e. all references to the trace chunks it contains must be released) before | |
39 | * it is destroyed. | |
40 | */ | |
2c5ff4e4 JG |
41 | void lttng_trace_chunk_registry_destroy( |
42 | struct lttng_trace_chunk_registry *registry); | |
43 | ||
44 | /* | |
45 | * Publish a trace chunk for a given session id. | |
46 | * A reference is acquired on behalf of the caller. | |
47 | * | |
48 | * The trace chunk that is returned is the published version of the trace | |
49 | * chunk. The chunk provided should be discarded on success and it's | |
50 | * published version used in its place. | |
51 | * | |
52 | * See the documentation of lttng_trace_chunk for more information on | |
53 | * the usage of the various parameters. | |
54 | * | |
55 | * Returns an lttng_trace_chunk on success, NULL on error. | |
56 | */ | |
2c5ff4e4 JG |
57 | struct lttng_trace_chunk *lttng_trace_chunk_registry_publish_chunk( |
58 | struct lttng_trace_chunk_registry *registry, | |
59 | uint64_t session_id, struct lttng_trace_chunk *chunk); | |
c5c79321 JG |
60 | /* |
61 | * Adds the `previously_published` parameter which allows the caller | |
62 | * to know if a trace chunk equivalent to `chunk` was previously published. | |
63 | * | |
64 | * The registry holds a reference to the published trace chunks it contains. | |
65 | * Trace chunks automatically unpublish themselves from their registry on | |
66 | * destruction. | |
67 | * | |
68 | * This information is necessary to drop the reference of newly published | |
69 | * chunks when a user doesn't wish to explicitly maintain all references | |
70 | * to a given trace chunk. | |
71 | * | |
72 | * For instance, the relay daemon doesn't need the registry to hold a | |
73 | * reference since it controls the lifetime of its trace chunks. | |
74 | * Conversely, the consumer daemons rely on the session daemon to inform | |
75 | * them of the end of life of a trace chunk and the trace chunks don't | |
76 | * belong to a specific top-level object: they are always retrieved from | |
77 | * the registry by `id`. | |
78 | */ | |
79 | struct lttng_trace_chunk *lttng_trace_chunk_registry_publish_chunk( | |
80 | struct lttng_trace_chunk_registry *registry, | |
81 | uint64_t session_id, struct lttng_trace_chunk *chunk, | |
82 | bool *previously_published); | |
2c5ff4e4 JG |
83 | |
84 | /* | |
85 | * Look-up a trace chunk by session_id and chunk_id. | |
86 | * A reference is acquired on behalf of the caller. | |
87 | * | |
88 | * Returns an lttng_trace_chunk on success, NULL if the chunk does not exist. | |
89 | */ | |
2c5ff4e4 JG |
90 | struct lttng_trace_chunk * |
91 | lttng_trace_chunk_registry_find_chunk( | |
92 | const struct lttng_trace_chunk_registry *registry, | |
93 | uint64_t session_id, uint64_t chunk_id); | |
94 | ||
6b584c2e JG |
95 | /* |
96 | * Query the existence of a trace chunk by session_id and chunk_id. | |
97 | * | |
98 | * Returns 0 on success, a negative value on error. | |
99 | */ | |
6b584c2e JG |
100 | int lttng_trace_chunk_registry_chunk_exists( |
101 | const struct lttng_trace_chunk_registry *registry, | |
102 | uint64_t session_id, uint64_t chunk_id, bool *chunk_exists); | |
103 | ||
2c5ff4e4 JG |
104 | /* |
105 | * Look-up an anonymous trace chunk by session_id. | |
106 | * A reference is acquired on behalf of the caller. | |
107 | * | |
108 | * Returns an lttng_trace_chunk on success, NULL if the chunk does not exist. | |
109 | */ | |
2c5ff4e4 JG |
110 | struct lttng_trace_chunk * |
111 | lttng_trace_chunk_registry_find_anonymous_chunk( | |
112 | const struct lttng_trace_chunk_registry *registry, | |
113 | uint64_t session_id); | |
114 | ||
e10aec8f | 115 | unsigned int lttng_trace_chunk_registry_put_each_chunk( |
8ced4811 | 116 | const struct lttng_trace_chunk_registry *registry); |
e10aec8f | 117 | |
2c5ff4e4 | 118 | #endif /* LTTNG_TRACE_CHUNK_REGISTRY_H */ |