blob: 4980f48ad95d60edbe55cf1333133b7a50494788 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
|
/*
* Copyright (c) 2011 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "vpx_config.h"
#define RTCD_C
#include "vpx_rtcd.h"
#if CONFIG_MULTITHREAD && HAVE_PTHREAD_H
#include <pthread.h>
static void once(void (*func)(void))
{
static pthread_once_t lock = PTHREAD_ONCE_INIT;
pthread_once(&lock, func);
}
#elif CONFIG_MULTITHREAD && defined(_WIN32)
#include <windows.h>
static void once(void (*func)(void))
{
/* Using a static initializer here rather than InitializeCriticalSection()
* since there's no race-free context in which to execute it. Protecting
* it with an atomic op like InterlockedCompareExchangePointer introduces
* an x86 dependency, and InitOnceExecuteOnce requires Vista.
*/
static CRITICAL_SECTION lock = {(void *)-1, -1, 0, 0, 0, 0};
static int done;
EnterCriticalSection(&lock);
if (!done)
{
func();
done = 1;
}
LeaveCriticalSection(&lock);
}
#else
/* No-op version that performs no synchronization. vpx_rtcd() is idempotent,
* so as long as your platform provides atomic loads/stores of pointers
* no synchronization is strictly necessary.
*/
static void once(void (*func)(void))
{
static int done;
if(!done)
{
func();
done = 1;
}
}
#endif
void vpx_rtcd()
{
once(setup_rtcd_internal);
}
|
