blob: ddef3827d0390e6fee79b7bff0cfe02bcf25915c (
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
70
71
72
73
74
|
/*
* Copyright (C) 2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_RS_LOCKLESS_FIFO_H
#define ANDROID_RS_LOCKLESS_FIFO_H
#include <stdint.h>
#include <sys/types.h>
#include <stdlib.h>
#include <pthread.h>
namespace android {
// A simple FIFO to be used as a producer / consumer between two
// threads. One is writer and one is reader. The common cases
// will not require locking. It is not threadsafe for multiple
// readers or writers by design.
class LocklessCommandFifo
{
public:
bool init(uint32_t size);
LocklessCommandFifo();
~LocklessCommandFifo();
protected:
uint8_t * volatile mPut;
uint8_t * volatile mGet;
uint8_t * mBuffer;
uint8_t * mEnd;
uint8_t mSize;
pthread_mutex_t mMutex;
pthread_cond_t mCondition;
public:
void * reserve(uint32_t bytes);
void commit(uint32_t command, uint32_t bytes);
void commitSync(uint32_t command, uint32_t bytes);
void flush();
const void * get(uint32_t *command, uint32_t *bytesData);
void next();
void makeSpace(uint32_t bytes);
bool isEmpty() const;
uint32_t getFreeSpace() const;
private:
void dumpState(const char *) const;
};
}
#endif
|
