1 /*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <stdlib.h>
18 #include "qsort_r_compat.h"
19
20 /*
21 * Note: This code is only used on the host, and is primarily here for
22 * Mac OS compatibility. Apparently, glibc and Apple's libc disagree on
23 * the parameter order for qsort_r.
24 */
25
26 #if HAVE_BSD_QSORT_R
27
28 /*
29 * BSD qsort_r parameter order is as we have defined here.
30 */
31
qsort_r_compat(void * base,size_t nel,size_t width,void * thunk,int (* compar)(void *,const void *,const void *))32 void qsort_r_compat(void* base, size_t nel, size_t width, void* thunk,
33 int (*compar)(void*, const void* , const void*)) {
34 qsort_r(base, nel, width, thunk, compar);
35 }
36
37 #elif HAVE_GNU_QSORT_R
38
39 /*
40 * GNU qsort_r parameter order places the thunk parameter last.
41 */
42
43 struct compar_data {
44 void* thunk;
45 int (*compar)(void*, const void* , const void*);
46 };
47
compar_wrapper(const void * a,const void * b,void * data)48 static int compar_wrapper(const void* a, const void* b, void* data) {
49 struct compar_data* compar_data = (struct compar_data*)data;
50 return compar_data->compar(compar_data->thunk, a, b);
51 }
52
qsort_r_compat(void * base,size_t nel,size_t width,void * thunk,int (* compar)(void *,const void *,const void *))53 void qsort_r_compat(void* base, size_t nel, size_t width, void* thunk,
54 int (*compar)(void*, const void* , const void*)) {
55 struct compar_data compar_data;
56 compar_data.thunk = thunk;
57 compar_data.compar = compar;
58 qsort_r(base, nel, width, compar_wrapper, &compar_data);
59 }
60
61 #else
62
63 /*
64 * Emulate qsort_r using thread local storage to access the thunk data.
65 */
66
67 #include <cutils/threads.h>
68
69 static thread_store_t compar_data_key = THREAD_STORE_INITIALIZER;
70
71 struct compar_data {
72 void* thunk;
73 int (*compar)(void*, const void* , const void*);
74 };
75
compar_wrapper(const void * a,const void * b)76 static int compar_wrapper(const void* a, const void* b) {
77 struct compar_data* compar_data = (struct compar_data*)thread_store_get(&compar_data_key);
78 return compar_data->compar(compar_data->thunk, a, b);
79 }
80
qsort_r_compat(void * base,size_t nel,size_t width,void * thunk,int (* compar)(void *,const void *,const void *))81 void qsort_r_compat(void* base, size_t nel, size_t width, void* thunk,
82 int (*compar)(void*, const void* , const void*)) {
83 struct compar_data compar_data;
84 compar_data.thunk = thunk;
85 compar_data.compar = compar;
86 thread_store_set(&compar_data_key, &compar_data, NULL);
87 qsort(base, nel, width, compar_wrapper);
88 }
89
90 #endif
91