1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3 * Copyright (c) 2014, Linaro Limited
4 * Copyright (c) 2020, Arm Limited
5 */
6 #include <stdlib.h>
7 #include <string.h>
8 #include <kernel/handle.h>
9
10 /*
11 * Define the initial capacity of the database. It should be a low number
12 * multiple of 2 since some databases a likely to only use a few handles.
13 * Since the algorithm is to doubles up when growing it shouldn't cause a
14 * noticable overhead on large databases.
15 */
16 #define HANDLE_DB_INITIAL_MAX_PTRS 4
17
handle_db_destroy(struct handle_db * db,void (* ptr_destructor)(void * ptr))18 void handle_db_destroy(struct handle_db *db, void (*ptr_destructor)(void *ptr))
19 {
20 if (db) {
21 if (ptr_destructor) {
22 size_t n = 0;
23
24 for (n = 0; n < db->max_ptrs; n++)
25 if (db->ptrs[n])
26 ptr_destructor(db->ptrs[n]);
27 }
28 free(db->ptrs);
29 db->ptrs = NULL;
30 db->max_ptrs = 0;
31 }
32 }
33
handle_db_is_empty(struct handle_db * db)34 bool handle_db_is_empty(struct handle_db *db)
35 {
36 size_t n = 0;
37
38 if (db) {
39 for (n = 0; n < db->max_ptrs; n++) {
40 if (db->ptrs[n])
41 return false;
42 }
43 }
44 return true;
45 }
46
handle_get(struct handle_db * db,void * ptr)47 int handle_get(struct handle_db *db, void *ptr)
48 {
49 size_t n;
50 void *p;
51 size_t new_max_ptrs;
52
53 if (!db || !ptr)
54 return -1;
55
56 /* Try to find an empty location */
57 for (n = 0; n < db->max_ptrs; n++) {
58 if (!db->ptrs[n]) {
59 db->ptrs[n] = ptr;
60 return n;
61 }
62 }
63
64 /* No location available, grow the ptrs array */
65 if (db->max_ptrs)
66 new_max_ptrs = db->max_ptrs * 2;
67 else
68 new_max_ptrs = HANDLE_DB_INITIAL_MAX_PTRS;
69 p = realloc(db->ptrs, new_max_ptrs * sizeof(void *));
70 if (!p)
71 return -1;
72 db->ptrs = p;
73 memset(db->ptrs + db->max_ptrs, 0,
74 (new_max_ptrs - db->max_ptrs) * sizeof(void *));
75 db->max_ptrs = new_max_ptrs;
76
77 /* Since n stopped at db->max_ptrs there is an empty location there */
78 db->ptrs[n] = ptr;
79 return n;
80 }
81
handle_put(struct handle_db * db,int handle)82 void *handle_put(struct handle_db *db, int handle)
83 {
84 void *p;
85
86 if (!db || handle < 0 || (size_t)handle >= db->max_ptrs)
87 return NULL;
88
89 p = db->ptrs[handle];
90 db->ptrs[handle] = NULL;
91 return p;
92 }
93
handle_lookup(struct handle_db * db,int handle)94 void *handle_lookup(struct handle_db *db, int handle)
95 {
96 if (!db || handle < 0 || (size_t)handle >= db->max_ptrs)
97 return NULL;
98
99 return db->ptrs[handle];
100 }
101