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246611b0 FD |
1 | /* |
2 | * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com> | |
3 | * | |
4 | * SPDX-License-Identifier: GPL-2.0-only | |
5 | * | |
6 | */ | |
7 | ||
246611b0 FD |
8 | #include <inttypes.h> |
9 | ||
10 | #include <urcu.h> | |
11 | #include <urcu/list.h> | |
12 | ||
c9e313bc SM |
13 | #include "macros.hpp" |
14 | #include "error.hpp" | |
246611b0 | 15 | |
c9e313bc | 16 | #include "index-allocator.hpp" |
246611b0 FD |
17 | |
18 | struct lttng_index_allocator { | |
19 | struct cds_list_head unused_list; | |
20 | uint64_t size; | |
21 | uint64_t position; | |
5e09ab50 | 22 | uint64_t nb_allocated_indexes; |
246611b0 FD |
23 | }; |
24 | ||
f1494934 | 25 | namespace { |
246611b0 FD |
26 | struct lttng_index { |
27 | uint64_t index; | |
28 | struct cds_list_head head; | |
29 | }; | |
f1494934 | 30 | } /* namespace */ |
246611b0 FD |
31 | |
32 | struct lttng_index_allocator *lttng_index_allocator_create( | |
33 | uint64_t index_count) | |
34 | { | |
35 | struct lttng_index_allocator *allocator = NULL; | |
36 | ||
64803277 | 37 | allocator = zmalloc<lttng_index_allocator>(); |
246611b0 FD |
38 | if (!allocator) { |
39 | PERROR("Failed to allocate index allocator"); | |
40 | goto end; | |
41 | } | |
42 | ||
43 | allocator->size = index_count; | |
44 | allocator->position = 0; | |
5e09ab50 | 45 | allocator->nb_allocated_indexes = 0; |
246611b0 FD |
46 | |
47 | CDS_INIT_LIST_HEAD(&allocator->unused_list); | |
48 | ||
49 | end: | |
50 | return allocator; | |
51 | } | |
52 | ||
53 | uint64_t lttng_index_allocator_get_index_count(struct lttng_index_allocator *allocator) | |
54 | { | |
5e09ab50 | 55 | return allocator->nb_allocated_indexes; |
246611b0 FD |
56 | } |
57 | ||
58 | enum lttng_index_allocator_status lttng_index_allocator_alloc( | |
59 | struct lttng_index_allocator *allocator, | |
60 | uint64_t *allocated_index) | |
61 | { | |
62 | enum lttng_index_allocator_status status = | |
63 | LTTNG_INDEX_ALLOCATOR_STATUS_OK; | |
64 | ||
65 | if (cds_list_empty(&allocator->unused_list)) { | |
66 | if (allocator->position >= allocator->size) { | |
67 | /* No indices left. */ | |
68 | status = LTTNG_INDEX_ALLOCATOR_STATUS_EMPTY; | |
69 | goto end; | |
70 | } | |
71 | ||
72 | *allocated_index = allocator->position++; | |
73 | } else { | |
74 | struct lttng_index *index; | |
75 | ||
76 | index = cds_list_first_entry(&allocator->unused_list, | |
77 | typeof(*index), head); | |
78 | cds_list_del(&index->head); | |
79 | *allocated_index = index->index; | |
80 | free(index); | |
81 | } | |
82 | ||
5e09ab50 | 83 | allocator->nb_allocated_indexes++; |
246611b0 FD |
84 | end: |
85 | return status; | |
86 | } | |
87 | ||
88 | enum lttng_index_allocator_status lttng_index_allocator_release( | |
89 | struct lttng_index_allocator *allocator, uint64_t idx) | |
90 | { | |
91 | struct lttng_index *index = NULL; | |
92 | enum lttng_index_allocator_status status = | |
93 | LTTNG_INDEX_ALLOCATOR_STATUS_OK; | |
94 | ||
a0377dfe | 95 | LTTNG_ASSERT(idx < allocator->size); |
246611b0 | 96 | |
64803277 | 97 | index = zmalloc<lttng_index>(); |
246611b0 FD |
98 | if (!index) { |
99 | PERROR("Failed to allocate free index queue"); | |
100 | status = LTTNG_INDEX_ALLOCATOR_STATUS_ERROR; | |
101 | goto end; | |
102 | } | |
103 | ||
104 | index->index = idx; | |
105 | cds_list_add_tail(&index->head, &allocator->unused_list); | |
5e09ab50 | 106 | allocator->nb_allocated_indexes--; |
246611b0 FD |
107 | |
108 | end: | |
109 | return status; | |
110 | } | |
111 | ||
112 | void lttng_index_allocator_destroy(struct lttng_index_allocator *allocator) | |
113 | { | |
114 | struct lttng_index *index = NULL, *tmp_index = NULL; | |
115 | ||
116 | if (!allocator) { | |
117 | return; | |
118 | } | |
119 | ||
120 | if (lttng_index_allocator_get_index_count(allocator) > 0) { | |
121 | WARN("Destroying index allocator with %" PRIu64 | |
122 | " slot indexes still in use", | |
123 | lttng_index_allocator_get_index_count(allocator)); | |
124 | } | |
125 | ||
126 | cds_list_for_each_entry_safe(index, tmp_index, | |
127 | &allocator->unused_list, head) { | |
128 | cds_list_del(&index->head); | |
129 | free(index); | |
130 | } | |
131 | ||
132 | free(allocator); | |
133 | } |