/[svn]/linuxsampler/tags/start/diskthread.cpp
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Contents of /linuxsampler/tags/start/diskthread.cpp

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Sat Oct 25 20:24:32 2003 UTC (20 years, 5 months ago) by (unknown author)
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This commit was manufactured by cvs2svn to create tag 'start'.
1 /***************************************************************************
2 * *
3 * LinuxSampler - modular, streaming capable sampler *
4 * *
5 * Copyright (C) 2003 by Benno Senoner *
6 * *
7 * This program is free software; you can redistribute it and/or modify *
8 * it under the terms of the GNU General Public License as published by *
9 * the Free Software Foundation; either version 2 of the License, or *
10 * (at your option) any later version. *
11 * *
12 * This program is distributed in the hope that it will be useful, *
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
15 * GNU General Public License for more details. *
16 * *
17 * You should have received a copy of the GNU General Public License *
18 * along with this program; if not, write to the Free Software *
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
20 * MA 02111-1307 USA *
21 ***************************************************************************/
22
23 #include "diskthread.h"
24
25
26 // *********** DiskThread **************
27 // *
28
29
30 // #########################################################################
31 // # Foreign Thread Section
32 // # (following code intended to be interface for audio thread)
33
34
35 /**
36 * Returns -1 if command queue is full, 0 on success (will be called by audio
37 * thread within the voice class).
38 */
39 int DiskThread::OrderNewStream(Stream::reference_t* pStreamRef, gig::Sample* pSample, unsigned long SampleOffset) {
40 dmsg(("Disk Thread: new stream ordered\n"));
41 if (CreationQueue->write_space() < 1) return -1;
42
43 pStreamRef->State = Stream::state_active;
44 pStreamRef->OrderID = CreateOrderID();
45 pStreamRef->hStream = CreateHandle();
46 pStreamRef->pStream = NULL; // a stream has to be activated by the disk thread first
47
48 create_command_t cmd;
49 cmd.pStreamRef = pStreamRef;
50 cmd.pSample = pSample;
51 cmd.SampleOffset = SampleOffset;
52
53 CreationQueue->write(&cmd, 1);
54 return 0;
55 }
56
57 /**
58 * Returns -1 if command queue is full, 0 on success (will be called by audio
59 * thread within the voice class).
60 */
61 int DiskThread::OrderDeletionOfStream(Stream::reference_t* pStreamRef) {
62 dmsg(("Disk Thread: stream deletion ordered\n"));
63 if (DeletionQueue->write_space() < 1) return -1;
64
65 delete_command_t cmd;
66 cmd.pStream = pStreamRef->pStream;
67 cmd.hStream = pStreamRef->hStream;
68 cmd.OrderID = pStreamRef->OrderID;
69
70 DeletionQueue->write(&cmd, 1);
71 return 0;
72 }
73
74 /**
75 * Returns the pointer to a disk stream if the ordered disk stream
76 * represented by the \a StreamOrderID was already activated by the disk
77 * thread, returns NULL otherwise. If the call was successful, thus if it
78 * returned a valid stream pointer, the caller has to the store that pointer
79 * by himself, because it's not possible to call this method again with the
80 * same used order ID; this method is just intended for picking up an ordered
81 * disk stream. This method will usually be called by the voice class (within
82 * the audio thread).
83 *
84 * @param StreamOrderID - ID previously returned by OrderNewStream()
85 * @returns pointer to created stream object, NULL otherwise
86 */
87 Stream* DiskThread::AskForCreatedStream(Stream::OrderID_t StreamOrderID) {
88 dmsg(("Disk Thread: been asked if stream already created, OrderID=%x ", StreamOrderID));
89 Stream* pStream = pCreatedStreams[StreamOrderID];
90 if (pStream) { dmsg(("(yes created)")) }
91 else { dmsg(("(no not yet created)")) }
92 pCreatedStreams[StreamOrderID] = NULL; // free the slot for a new order
93 return pStream;
94 }
95
96
97
98 // #########################################################################
99 // # Disk Thread Only Section
100 // # (following code should only be executed by the disk thread)
101
102
103 DiskThread::DiskThread(uint BufferWrapElements) : Thread(false, 1, -2) {
104 CreationQueue = new RingBuffer<create_command_t>(1024);
105 DeletionQueue = new RingBuffer<delete_command_t>(1024);
106 Streams = MAX_INPUT_STREAMS;
107 RefillStreamsPerRun = 4;
108 for (int i = 0; i < MAX_INPUT_STREAMS; i++) {
109 pStreams[i] = new Stream(131072, BufferWrapElements); // 131072 sample words
110 }
111 for (int i = 1; i <= MAX_INPUT_STREAMS; i++) {
112 pCreatedStreams[i] = NULL;
113 }
114 }
115
116 DiskThread::~DiskThread() {
117 for (int i = 0; i < MAX_INPUT_STREAMS; i++) {
118 if (pStreams[i]) delete pStreams[i];
119 }
120 if (CreationQueue) delete CreationQueue;
121 if (DeletionQueue) delete DeletionQueue;
122 }
123
124 int DiskThread::Main() {
125 dmsg(("Disk thread running\n"));
126 while (true) {
127 IsIdle = true; // will be set to false if a stream got filled
128
129 // if there are creation commands, create new streams
130 while (Stream::UnusedStreams > 0 && CreationQueue->read_space() > 0) {
131 create_command_t command;
132 CreationQueue->read(&command, 1);
133 CreateStream(command);
134 }
135
136 // if there are deletion commands, delete those streams
137 while (Stream::UnusedStreams < Streams && DeletionQueue->read_space() > 0) {
138 delete_command_t command;
139 DeletionQueue->read(&command, 1);
140 DeleteStream(command);
141 }
142
143 RefillStreams(); // refill the most empty streams
144
145 // if nothing was done during this iteration (eg no streambuffer
146 // filled with data) then sleep for 50ms
147 if (IsIdle) usleep(30000);
148 }
149
150 return EXIT_FAILURE;
151 }
152
153 void DiskThread::CreateStream(create_command_t& Command) {
154 // search for unused stream
155 Stream* newstream = NULL;
156 for (int i = Streams - 1; i >= 0; i--) {
157 if (pStreams[i]->GetState() == Stream::state_unused) {
158 newstream = pStreams[i];
159 break;
160 }
161 }
162 if (!newstream) {
163 dmsg(("No unused stream found (OrderID:%x) - report if this happens, this is a bug!\n", Command.pStreamRef->OrderID));
164 return;
165 }
166 dmsg(("new Stream launched by disk thread (OrderID:%x,StreamHandle:%x)\n", Command.pStreamRef->OrderID, Command.pStreamRef->hStream));
167 newstream->Launch(Command.pStreamRef, Command.pSample, Command.SampleOffset);
168 pCreatedStreams[Command.pStreamRef->OrderID] = newstream;
169 }
170
171 void DiskThread::DeleteStream(delete_command_t& Command) {
172 if (Command.pStream) Command.pStream->Kill();
173 else { // the stream wasn't created by disk thread or picked up by audio thread yet
174
175 // stream was created but not picked up yet
176 Stream* pStream = pCreatedStreams[Command.OrderID];
177 if (pStream) {
178 pStream->Kill();
179 pCreatedStreams[Command.OrderID] = NULL; // free slot for new order
180 return;
181 }
182
183 // else we have to compare the handle with the one's of all streams
184 // (this case should occur only very rarely)
185 for (int i = 0; i < this->Streams; i++) {
186 if (pStreams[i]->GetHandle() == Command.hStream) {
187 pStreams[i]->Kill();
188 return;
189 }
190 }
191 }
192 }
193
194 void DiskThread::RefillStreams() {
195 // sort the streams by most empty stream
196 qsort(pStreams, Streams, sizeof(Stream*), CompareStreamWriteSpace);
197
198 // refill the most empty streams
199 for (uint i = 0; i < RefillStreamsPerRun; i++) {
200 if (pStreams[i]->GetState() == Stream::state_active) {
201
202 //float filledpercentage = (float) pStreams[i]->GetReadSpace() / 131072.0 * 100.0;
203 //dmsg(("\nbuffer fill: %.1f%\n", filledpercentage));
204
205 int writespace = pStreams[i]->GetWriteSpaceToEnd();
206 if (writespace == 0) break;
207
208 int capped_writespace = writespace;
209 // if there is too much buffer space available then cut the read/write
210 // size to MAX_REFILL_SIZE which is by default 65536 samples = 256KBytes
211 if (writespace > MAX_REFILL_SIZE) capped_writespace = MAX_REFILL_SIZE;
212
213 // adjust the amount to read in order to ensure that the buffer wraps correctly
214 int read_amount = pStreams[i]->AdjustWriteSpaceToAvoidBoundary(writespace, capped_writespace);
215 // if we wasn't able to refill one of the stream buffers by more than
216 // MIN_REFILL_SIZE we'll send the disk thread to sleep later
217 if (pStreams[i]->ReadAhead(read_amount) > MIN_REFILL_SIZE) this->IsIdle = false;
218 }
219 }
220 }
221
222 /// Handle Generator
223 Stream::Handle DiskThread::CreateHandle() {
224 static uint32_t counter = 0;
225 if (counter == 0xffffffff) counter = 1; // we use '0' as 'invalid handle' only, so we skip 0
226 else counter++;
227 return counter;
228 }
229
230 /// order ID Generator
231 Stream::OrderID_t DiskThread::CreateOrderID() {
232 static uint32_t counter = 0;
233 do {
234 if (counter == MAX_INPUT_STREAMS) counter = 1; // we use '0' as 'invalid order' only, so we skip 0
235 else counter++;
236 } while (pCreatedStreams[counter]); // until empty slot found
237 return counter;
238 }
239
240
241
242 // *********** C functions **************
243 // *
244
245 /**
246 * This is the comparison function the qsort algo uses to determine if a value is
247 * bigger than another one or special in our case; if the writespace of a stream
248 * is bigger than another one.
249 */
250 int CompareStreamWriteSpace(const void* A, const void* B) {
251 Stream* a = *(Stream**) A;
252 Stream* b = *(Stream**) B;
253 return b->GetWriteSpace() - a->GetWriteSpace();
254 }

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