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
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
|
/*
* 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.
*/
#include "rsLocklessFifo.h"
using namespace android;
LocklessCommandFifo::LocklessCommandFifo()
{
}
LocklessCommandFifo::~LocklessCommandFifo()
{
if (!mInShutdown) {
shutdown();
}
free(mBuffer);
}
void LocklessCommandFifo::shutdown()
{
mInShutdown = true;
mSignalToWorker.set();
}
bool LocklessCommandFifo::init(uint32_t sizeInBytes)
{
// Add room for a buffer reset command
mBuffer = static_cast<uint8_t *>(malloc(sizeInBytes + 4));
if (!mBuffer) {
LOGE("LocklessFifo allocation failure");
return false;
}
if (!mSignalToControl.init() || !mSignalToWorker.init()) {
LOGE("Signal setup failed");
free(mBuffer);
return false;
}
mInShutdown = false;
mSize = sizeInBytes;
mPut = mBuffer;
mGet = mBuffer;
mEnd = mBuffer + (sizeInBytes) - 1;
dumpState("init");
return true;
}
uint32_t LocklessCommandFifo::getFreeSpace() const
{
int32_t freeSpace = 0;
//dumpState("getFreeSpace");
if (mPut >= mGet) {
freeSpace = mEnd - mPut;
} else {
freeSpace = mGet - mPut;
}
if (freeSpace < 0) {
freeSpace = 0;
}
return freeSpace;
}
bool LocklessCommandFifo::isEmpty() const
{
return mPut == mGet;
}
void * LocklessCommandFifo::reserve(uint32_t sizeInBytes)
{
// Add space for command header and loop token;
sizeInBytes += 8;
//dumpState("reserve");
if (getFreeSpace() < sizeInBytes) {
makeSpace(sizeInBytes);
}
return mPut + 4;
}
void LocklessCommandFifo::commit(uint32_t command, uint32_t sizeInBytes)
{
if (mInShutdown) {
return;
}
//dumpState("commit 1");
reinterpret_cast<uint16_t *>(mPut)[0] = command;
reinterpret_cast<uint16_t *>(mPut)[1] = sizeInBytes;
mPut += ((sizeInBytes + 3) & ~3) + 4;
//dumpState("commit 2");
mSignalToWorker.set();
}
void LocklessCommandFifo::commitSync(uint32_t command, uint32_t sizeInBytes)
{
if (mInShutdown) {
return;
}
commit(command, sizeInBytes);
flush();
}
void LocklessCommandFifo::flush()
{
//dumpState("flush 1");
while(mPut != mGet) {
mSignalToControl.wait();
}
//dumpState("flush 2");
}
const void * LocklessCommandFifo::get(uint32_t *command, uint32_t *bytesData)
{
while(1) {
//dumpState("get");
while(isEmpty() && !mInShutdown) {
mSignalToControl.set();
mSignalToWorker.wait();
}
if (mInShutdown) {
*command = 0;
*bytesData = 0;
return 0;
}
*command = reinterpret_cast<const uint16_t *>(mGet)[0];
*bytesData = reinterpret_cast<const uint16_t *>(mGet)[1];
if (*command) {
// non-zero command is valid
return mGet+4;
}
// zero command means reset to beginning.
mGet = mBuffer;
}
}
void LocklessCommandFifo::next()
{
uint32_t bytes = reinterpret_cast<const uint16_t *>(mGet)[1];
mGet += ((bytes + 3) & ~3) + 4;
if (isEmpty()) {
mSignalToControl.set();
}
//dumpState("next");
}
void LocklessCommandFifo::makeSpace(uint32_t bytes)
{
//dumpState("make space");
if ((mPut+bytes) > mEnd) {
// Need to loop regardless of where get is.
while((mGet > mPut) && (mBuffer+4 >= mGet)) {
usleep(100);
}
// Toss in a reset then the normal wait for space will do the rest.
reinterpret_cast<uint16_t *>(mPut)[0] = 0;
reinterpret_cast<uint16_t *>(mPut)[1] = 0;
mPut = mBuffer;
}
// it will fit here so we just need to wait for space.
while(getFreeSpace() < bytes) {
usleep(100);
}
}
void LocklessCommandFifo::dumpState(const char *s) const
{
LOGV("%s put %p, get %p, buf %p, end %p", s, mPut, mGet, mBuffer, mEnd);
}
LocklessCommandFifo::Signal::Signal()
{
mSet = true;
}
LocklessCommandFifo::Signal::~Signal()
{
pthread_mutex_destroy(&mMutex);
pthread_cond_destroy(&mCondition);
}
bool LocklessCommandFifo::Signal::init()
{
int status = pthread_mutex_init(&mMutex, NULL);
if (status) {
LOGE("LocklessFifo mutex init failure");
return false;
}
status = pthread_cond_init(&mCondition, NULL);
if (status) {
LOGE("LocklessFifo condition init failure");
pthread_mutex_destroy(&mMutex);
return false;
}
return true;
}
void LocklessCommandFifo::Signal::set()
{
int status;
status = pthread_mutex_lock(&mMutex);
if (status) {
LOGE("LocklessCommandFifo: error %i locking for set condition.", status);
return;
}
mSet = true;
status = pthread_cond_signal(&mCondition);
if (status) {
LOGE("LocklessCommandFifo: error %i on set condition.", status);
}
status = pthread_mutex_unlock(&mMutex);
if (status) {
LOGE("LocklessCommandFifo: error %i unlocking for set condition.", status);
}
}
void LocklessCommandFifo::Signal::wait()
{
int status;
status = pthread_mutex_lock(&mMutex);
if (status) {
LOGE("LocklessCommandFifo: error %i locking for condition.", status);
return;
}
if (!mSet) {
status = pthread_cond_wait(&mCondition, &mMutex);
if (status) {
LOGE("LocklessCommandFifo: error %i waiting on condition.", status);
}
}
mSet = false;
status = pthread_mutex_unlock(&mMutex);
if (status) {
LOGE("LocklessCommandFifo: error %i unlocking for condition.", status);
}
}
|