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d3e2ba59 JD |
1 | /* |
2 | * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com> | |
3 | * David Goulet <dgoulet@efficios.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU General Public License, version 2 only, as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
12 | * more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License along with | |
15 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
16 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
17 | */ | |
18 | ||
19 | #define _GNU_SOURCE | |
20 | #include <assert.h> | |
21 | ||
22 | #include <common/common.h> | |
23 | #include <common/utils.h> | |
24 | ||
25 | #include "ctf-trace.h" | |
26 | ||
27 | static uint64_t last_relay_ctf_trace_id; | |
28 | ||
29 | /* | |
30 | * Try to destroy a ctf_trace object meaning that the refcount is decremented | |
31 | * and checked if down to 0 which will free it. | |
32 | */ | |
33 | void ctf_trace_try_destroy(struct ctf_trace *obj) | |
34 | { | |
35 | unsigned long ret_ref; | |
36 | ||
37 | if (!obj) { | |
38 | return; | |
39 | } | |
40 | ||
41 | ret_ref = uatomic_add_return(&obj->refcount, -1); | |
d3e2ba59 JD |
42 | if (ret_ref == 0) { |
43 | DBG("Freeing ctf_trace %" PRIu64, obj->id); | |
44 | free(obj); | |
45 | } | |
46 | } | |
47 | ||
48 | /* | |
49 | * Create and return an allocated ctf_trace object. NULL on error. | |
50 | */ | |
51 | struct ctf_trace *ctf_trace_create(void) | |
52 | { | |
53 | struct ctf_trace *obj; | |
54 | ||
55 | obj = zmalloc(sizeof(*obj)); | |
56 | if (!obj) { | |
57 | PERROR("ctf_trace alloc"); | |
58 | goto error; | |
59 | } | |
60 | ||
61 | obj->id = ++last_relay_ctf_trace_id; | |
62 | DBG("Created ctf_trace %" PRIu64, obj->id); | |
63 | ||
64 | error: | |
65 | return obj; | |
66 | } | |
67 | ||
68 | /* | |
69 | * Check if we can assign the ctf_trace id and metadata stream to one or all | |
70 | * the streams with the same path_name (our unique ID for ctf traces). | |
71 | * | |
72 | * The given stream MUST be new and NOT visible (in any hash table). | |
73 | */ | |
74 | void ctf_trace_assign(struct lttng_ht *ht, struct relay_stream *stream) | |
75 | { | |
76 | struct lttng_ht_iter iter; | |
77 | struct relay_stream *tmp_stream; | |
78 | ||
79 | assert(ht); | |
80 | assert(stream); | |
81 | ||
82 | rcu_read_lock(); | |
83 | cds_lfht_for_each_entry_duplicate(ht->ht, | |
84 | ht->hash_fct((void *) stream->path_name, lttng_ht_seed), | |
85 | ht->match_fct, (void *) stream->path_name, | |
86 | &iter.iter, tmp_stream, ctf_trace_node.node) { | |
87 | if (stream->metadata_flag) { | |
88 | /* | |
89 | * The new stream is the metadata stream for this trace, | |
90 | * assign the ctf_trace pointer to all the streams in | |
91 | * this bucket. | |
92 | */ | |
93 | pthread_mutex_lock(&tmp_stream->lock); | |
94 | tmp_stream->ctf_trace = stream->ctf_trace; | |
95 | uatomic_inc(&tmp_stream->ctf_trace->refcount); | |
96 | pthread_mutex_unlock(&tmp_stream->lock); | |
97 | DBG("Assigned ctf_trace %" PRIu64 " to stream %" PRIu64, | |
98 | tmp_stream->ctf_trace->id, tmp_stream->stream_handle); | |
99 | } else if (tmp_stream->ctf_trace) { | |
100 | /* | |
101 | * The ctf_trace already exists for this bucket, | |
102 | * just assign the pointer to the new stream and exit. | |
103 | */ | |
104 | stream->ctf_trace = tmp_stream->ctf_trace; | |
105 | uatomic_inc(&stream->ctf_trace->refcount); | |
106 | DBG("Assigned ctf_trace %" PRIu64 " to stream %" PRIu64, | |
107 | tmp_stream->ctf_trace->id, tmp_stream->stream_handle); | |
108 | goto end; | |
109 | } else { | |
110 | /* | |
111 | * We don't know yet the ctf_trace ID (no metadata has been added), | |
112 | * so leave it there until the metadata stream arrives. | |
113 | */ | |
114 | goto end; | |
115 | } | |
116 | } | |
117 | ||
118 | end: | |
119 | rcu_read_unlock(); | |
120 | return; | |
121 | } | |
122 |