engines/gig/DiskThread.cpp

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *   Copyright (C) 2005 Christian Schoenebeck                              *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the Free Software           *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#include <sstream>

#include "DiskThread.h"

namespace LinuxSampler { namespace gig {

    // *********** DiskThread **************
    // *


    // just a placeholder to mark a cell in the pickup array as 'reserved'
    Stream* DiskThread::SLOT_RESERVED = (Stream*) &SLOT_RESERVED;


    // #########################################################################
    // # Foreign Thread Section
    // #         (following code intended to be interface for audio thread)


    /**
     * Suspend disk thread, kill all active streams, clear all queues and the
     * pickup array and reset all streams. Call this method to bring everything
     * in the disk thread to day one. If the disk thread was running, it will be
     * respawned right after everything was reset.
     */
    void DiskThread::Reset() {
        bool running = this->IsRunning();
        if (running) this->StopThread();
        for (int i = 0; i < MAX_INPUT_STREAMS; i++) {
            pStreams[i]->Kill();
        }
        for (int i = 1; i <= MAX_INPUT_STREAMS; i++) {
            pCreatedStreams[i] = NULL;
        }
        GhostQueue->init();
        CreationQueue->init();
        DeletionQueue->init();
        ActiveStreamCount = 0;
        ActiveStreamCountMax = 0;
        if (running) this->StartThread(); // start thread only if it was running before
    }

    String DiskThread::GetBufferFillBytes() {
        bool activestreams = false;
        std::stringstream ss;
        for (uint i = 0; i < this->Streams; i++) {
            if (pStreams[i]->GetState() == Stream::state_unused) continue;
            uint bufferfill = pStreams[i]->GetReadSpace() * sizeof(sample_t);
            uint streamid   = (uint) pStreams[i]->GetHandle();
            if (!streamid) continue;

            if (activestreams) ss << ",[" << streamid << ']' << bufferfill;
            else {
                ss << '[' << streamid << ']' << bufferfill;
                activestreams = true;
            }
        }
        return ss.str();
    }

    String DiskThread::GetBufferFillPercentage() {
        bool activestreams = false;
        std::stringstream ss;
        for (uint i = 0; i < this->Streams; i++) {
            if (pStreams[i]->GetState() == Stream::state_unused) continue;
            uint bufferfill = (uint) ((float) pStreams[i]->GetReadSpace() / (float) STREAM_BUFFER_SIZE * 100);
            uint streamid   = (uint) pStreams[i]->GetHandle();
            if (!streamid) continue;

            if (activestreams) ss << ",[" << streamid << ']' << bufferfill << '%';
            else {
                ss << '[' << streamid << ']' << bufferfill;
                activestreams = true;
            }
        }
        return ss.str();
    }

    /**
     * Returns -1 if command queue or pickup pool is full, 0 on success (will be
     * called by audio thread within the voice class).
     */
    int DiskThread::OrderNewStream(Stream::reference_t* pStreamRef, ::gig::Sample* pSample, unsigned long SampleOffset, bool DoLoop) {
        dmsg(4,("Disk Thread: new stream ordered\n"));
        if (CreationQueue->write_space() < 1) {
            dmsg(1,("DiskThread: Order queue full!\n"));
            return -1;
        }

        const Stream::OrderID_t newOrder = CreateOrderID();
        if (!newOrder) {
                dmsg(1,("DiskThread: there was no free slot\n"));
                return -1; // there was no free slot
        }

        pStreamRef->State   = Stream::state_active;
        pStreamRef->OrderID = newOrder;
        pStreamRef->hStream = CreateHandle();
        pStreamRef->pStream = NULL; // a stream has to be activated by the disk thread first

        create_command_t cmd;
        cmd.OrderID      = pStreamRef->OrderID;
        cmd.hStream      = pStreamRef->hStream;
        cmd.pStreamRef   = pStreamRef;
        cmd.pSample      = pSample;
        cmd.SampleOffset = SampleOffset;
        cmd.DoLoop       = DoLoop;

        CreationQueue->push(&cmd);
        return 0;
    }

    /**
     * Returns -1 if command queue is full, 0 on success (will be called by audio
     * thread within the voice class).
     */
    int DiskThread::OrderDeletionOfStream(Stream::reference_t* pStreamRef) {
        dmsg(4,("Disk Thread: stream deletion ordered\n"));
        if (DeletionQueue->write_space() < 1) {
            dmsg(1,("DiskThread: Deletion queue full!\n"));
            return -1;
        }

        delete_command_t cmd;
        cmd.pStream = pStreamRef->pStream;
        cmd.hStream = pStreamRef->hStream;
        cmd.OrderID = pStreamRef->OrderID;

        DeletionQueue->push(&cmd);
        return 0;
    }

    /**
     * Returns the pointer to a disk stream if the ordered disk stream
     * represented by the \a StreamOrderID was already activated by the disk
     * thread, returns NULL otherwise. If the call was successful, thus if it
     * returned a valid stream pointer, the caller has to the store that pointer
     * by himself, because it's not possible to call this method again with the
     * same used order ID; this method is just intended for picking up an ordered
     * disk stream. This method will usually be called by the voice class (within
     * the audio thread).
     *
     * @param StreamOrderID - ID previously returned by OrderNewStream()
     * @returns               pointer to created stream object, NULL otherwise
     */
    Stream* DiskThread::AskForCreatedStream(Stream::OrderID_t StreamOrderID) {
        dmsg(4,("Disk Thread: been asked if stream already created, OrderID=%x ", StreamOrderID));
        Stream* pStream = pCreatedStreams[StreamOrderID];
        if (pStream && pStream != SLOT_RESERVED) {
            dmsg(4,("(yes created)\n"));
            pCreatedStreams[StreamOrderID] = NULL; // free the slot for a new order
            return pStream;
        }
        dmsg(4,("(no not yet created)\n"));
        return NULL;
    }


    // #########################################################################
    // # Disk Thread Only Section
    // #         (following code should only be executed by the disk thread)


    DiskThread::DiskThread(uint BufferWrapElements) : Thread(true, false, 1, -2) {
        DecompressionBuffer = ::gig::Sample::CreateDecompressionBuffer(MAX_REFILL_SIZE);
        CreationQueue       = new RingBuffer<create_command_t>(1024);
        DeletionQueue       = new RingBuffer<delete_command_t>(1024);
        GhostQueue          = new RingBuffer<Stream::Handle>(MAX_INPUT_STREAMS);
        Streams             = MAX_INPUT_STREAMS;
        RefillStreamsPerRun = REFILL_STREAMS_PER_RUN;
        for (int i = 0; i < MAX_INPUT_STREAMS; i++) {
            pStreams[i] = new Stream(&DecompressionBuffer, STREAM_BUFFER_SIZE, BufferWrapElements); // 131072 sample words
        }
        for (int i = 1; i <= MAX_INPUT_STREAMS; i++) {
            pCreatedStreams[i] = NULL;
        }
    }

    DiskThread::~DiskThread() {
        for (int i = 0; i < MAX_INPUT_STREAMS; i++) {
            if (pStreams[i]) delete pStreams[i];
        }
        if (CreationQueue) delete CreationQueue;
        if (DeletionQueue) delete DeletionQueue;
        if (GhostQueue)    delete GhostQueue;
        ::gig::Sample::DestroyDecompressionBuffer(DecompressionBuffer);
    }

    int DiskThread::Main() {
        dmsg(3,("Disk thread running\n"));
        while (true) {
            pthread_testcancel(); // mandatory for OSX
            IsIdle = true; // will be set to false if a stream got filled

            // if there are ghost streams, delete them
            for (int i = 0; i < GhostQueue->read_space(); i++) { //FIXME: unefficient
                Stream::Handle hGhostStream;
                GhostQueue->pop(&hGhostStream);
                bool found = false;
                for (int i = 0; i < this->Streams; i++) {
                    if (pStreams[i]->GetHandle() == hGhostStream) {
                        pStreams[i]->Kill();
                        found = true;
                        break;
                    }
                }
                if (!found) GhostQueue->push(&hGhostStream); // put ghost stream handle back to the queue
            }

            // if there are creation commands, create new streams
            while (Stream::UnusedStreams > 0 && CreationQueue->read_space() > 0) {
                create_command_t command;
                CreationQueue->pop(&command);
                CreateStream(command);
            }

            // if there are deletion commands, delete those streams
            while (Stream::UnusedStreams < Stream::TotalStreams && DeletionQueue->read_space() > 0) {
                delete_command_t command;
                DeletionQueue->pop(&command);
                DeleteStream(command);
            }

            RefillStreams(); // refill the most empty streams

            // if nothing was done during this iteration (eg no streambuffer
            // filled with data) then sleep for 50ms
            if (IsIdle) usleep(30000);

            int streamsInUsage = 0;
            for (int i = Streams - 1; i >= 0; i--) {
                if (pStreams[i]->GetState() != Stream::state_unused) streamsInUsage++;
            }
            ActiveStreamCount = streamsInUsage;
            if (streamsInUsage > ActiveStreamCountMax) ActiveStreamCountMax = streamsInUsage;
        }

        return EXIT_FAILURE;
    }

    void DiskThread::CreateStream(create_command_t& Command) {
        // search for unused stream
        Stream* newstream = NULL;
        for (int i = Streams - 1; i >= 0; i--) {
            if (pStreams[i]->GetState() == Stream::state_unused) {
                newstream = pStreams[i];
                break;
            }
        }
        if (!newstream) {
            std::cerr << "No unused stream found (OrderID:" << Command.OrderID << ") - report if this happens, this is a bug!\n" << std::flush;
            return;
        }
        newstream->Launch(Command.hStream, Command.pStreamRef, Command.pSample, Command.SampleOffset, Command.DoLoop);
        dmsg(4,("new Stream launched by disk thread (OrderID:%d,StreamHandle:%d)\n", Command.OrderID, Command.hStream));
        if (pCreatedStreams[Command.OrderID] != SLOT_RESERVED) {
            std::cerr << "DiskThread: Slot " << Command.OrderID << " already occupied! Please report this!\n" << std::flush;
            newstream->Kill();
            return;
        }
        pCreatedStreams[Command.OrderID] = newstream;
    }

    void DiskThread::DeleteStream(delete_command_t& Command) {
        if (Command.pStream) Command.pStream->Kill();
        else { // the stream wasn't created by disk thread or picked up by audio thread yet

            // if stream was created but not picked up yet
            Stream* pStream = pCreatedStreams[Command.OrderID];
            if (pStream && pStream != SLOT_RESERVED) {
                pStream->Kill();
                pCreatedStreams[Command.OrderID] = NULL; // free slot for new order
                return;
            }

            // the stream was not created yet
            if (GhostQueue->write_space() > 0) {
                GhostQueue->push(&Command.hStream);
            }
            else dmsg(1,("DiskThread: GhostQueue full!\n"));
        }
    }

    void DiskThread::RefillStreams() {
        // sort the streams by most empty stream
        qsort(pStreams, Streams, sizeof(Stream*), CompareStreamWriteSpace);

        // refill the most empty streams
        for (uint i = 0; i < RefillStreamsPerRun; i++) {
            if (pStreams[i]->GetState() == Stream::state_active) {

                //float filledpercentage = (float) pStreams[i]->GetReadSpace() / 131072.0 * 100.0;
                //dmsg(("\nbuffer fill: %.1f%\n", filledpercentage));

                int writespace = pStreams[i]->GetWriteSpaceToEnd();
                if (writespace == 0) break;

                int capped_writespace = writespace;
                // if there is too much buffer space available then cut the read/write
                // size to MAX_REFILL_SIZE which is by default 65536 samples = 256KBytes
                if (writespace > MAX_REFILL_SIZE) capped_writespace = MAX_REFILL_SIZE;

                // adjust the amount to read in order to ensure that the buffer wraps correctly
                int read_amount = pStreams[i]->AdjustWriteSpaceToAvoidBoundary(writespace, capped_writespace);
                // if we wasn't able to refill one of the stream buffers by more than
                // MIN_REFILL_SIZE we'll send the disk thread to sleep later
                if (pStreams[i]->ReadAhead(read_amount) > MIN_REFILL_SIZE) this->IsIdle = false;
            }
        }
    }

    /// Handle Generator
    Stream::Handle DiskThread::CreateHandle() {
        static uint32_t counter = 0;
        if (counter == 0xffffffff) counter = 1; // we use '0' as 'invalid handle' only, so we skip 0
        else                       counter++;
        return counter;
    }

    /// order ID Generator
    Stream::OrderID_t DiskThread::CreateOrderID() {
        static Stream::OrderID_t counter(0);
        for (int i = 0; i < MAX_INPUT_STREAMS; i++) {
            if (counter == MAX_INPUT_STREAMS) counter = 1; // we use '0' as 'invalid order' only, so we skip 0
            else                              counter++;
            if (!pCreatedStreams[counter]) {
                pCreatedStreams[counter] = SLOT_RESERVED; // mark this slot as reserved
                return counter;                           // found empty slot
            }
        }
        return 0; // no free slot
    }


    // *********** C functions **************
    // *

    /**
     * This is the comparison function the qsort algo uses to determine if a value is
     * bigger than another one or special in our case; if the writespace of a stream
     * is bigger than another one.
     */
    int CompareStreamWriteSpace(const void* A, const void* B) {
        Stream* a = *(Stream**) A;
        Stream* b = *(Stream**) B;
        return b->GetWriteSpace() - a->GetWriteSpace();
    }

}} // namespace LinuxSampler::gig
1	schoenebeck	53	/***************************************************************************
2			* *
3			* LinuxSampler - modular, streaming capable sampler *
4			* *
5	schoenebeck	56	* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	schoenebeck	385	* Copyright (C) 2005 Christian Schoenebeck *
7	schoenebeck	53	* *
8			* This program is free software; you can redistribute it and/or modify *
9			* it under the terms of the GNU General Public License as published by *
10			* the Free Software Foundation; either version 2 of the License, or *
11			* (at your option) any later version. *
12			* *
13			* This program is distributed in the hope that it will be useful, *
14			* but WITHOUT ANY WARRANTY; without even the implied warranty of *
15			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16			* GNU General Public License for more details. *
17			* *
18			* You should have received a copy of the GNU General Public License *
19			* along with this program; if not, write to the Free Software *
20			* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
21			* MA 02111-1307 USA *
22			***************************************************************************/
23
24			#include <sstream>
25
26			#include "DiskThread.h"
27
28			namespace LinuxSampler { namespace gig {
29
30			// ********* DiskThread ************
31			// *
32
33
34			// just a placeholder to mark a cell in the pickup array as 'reserved'
35			Stream* DiskThread::SLOT_RESERVED = (Stream*) &SLOT_RESERVED;
36
37
38			// #########################################################################
39			// # Foreign Thread Section
40			// # (following code intended to be interface for audio thread)
41
42
43			/**
44			* Suspend disk thread, kill all active streams, clear all queues and the
45			* pickup array and reset all streams. Call this method to bring everything
46			* in the disk thread to day one. If the disk thread was running, it will be
47			* respawned right after everything was reset.
48			*/
49			void DiskThread::Reset() {
50			bool running = this->IsRunning();
51			if (running) this->StopThread();
52			for (int i = 0; i < MAX_INPUT_STREAMS; i++) {
53			pStreams[i]->Kill();
54			}
55			for (int i = 1; i <= MAX_INPUT_STREAMS; i++) {
56			pCreatedStreams[i] = NULL;
57			}
58			GhostQueue->init();
59			CreationQueue->init();
60			DeletionQueue->init();
61			ActiveStreamCount = 0;
62			ActiveStreamCountMax = 0;
63			if (running) this->StartThread(); // start thread only if it was running before
64			}
65
66			String DiskThread::GetBufferFillBytes() {
67			bool activestreams = false;
68			std::stringstream ss;
69			for (uint i = 0; i < this->Streams; i++) {
70			if (pStreams[i]->GetState() == Stream::state_unused) continue;
71			uint bufferfill = pStreams[i]->GetReadSpace() * sizeof(sample_t);
72			uint streamid = (uint) pStreams[i]->GetHandle();
73			if (!streamid) continue;
74
75			if (activestreams) ss << ",[" << streamid << ']' << bufferfill;
76			else {
77			ss << '[' << streamid << ']' << bufferfill;
78			activestreams = true;
79			}
80			}
81			return ss.str();
82			}
83
84			String DiskThread::GetBufferFillPercentage() {
85			bool activestreams = false;
86			std::stringstream ss;
87			for (uint i = 0; i < this->Streams; i++) {
88			if (pStreams[i]->GetState() == Stream::state_unused) continue;
89			uint bufferfill = (uint) ((float) pStreams[i]->GetReadSpace() / (float) STREAM_BUFFER_SIZE * 100);
90			uint streamid = (uint) pStreams[i]->GetHandle();
91			if (!streamid) continue;
92
93			if (activestreams) ss << ",[" << streamid << ']' << bufferfill << '%';
94			else {
95			ss << '[' << streamid << ']' << bufferfill;
96			activestreams = true;
97			}
98			}
99			return ss.str();
100			}
101
102			/**
103			* Returns -1 if command queue or pickup pool is full, 0 on success (will be
104			* called by audio thread within the voice class).
105			*/
106			int DiskThread::OrderNewStream(Stream::reference_t* pStreamRef, ::gig::Sample* pSample, unsigned long SampleOffset, bool DoLoop) {
107			dmsg(4,("Disk Thread: new stream ordered\n"));
108			if (CreationQueue->write_space() < 1) {
109			dmsg(1,("DiskThread: Order queue full!\n"));
110			return -1;
111			}
112
113	senkov	329	const Stream::OrderID_t newOrder = CreateOrderID();
114			if (!newOrder) {
115			dmsg(1,("DiskThread: there was no free slot\n"));
116			return -1; // there was no free slot
117			}
118
119	schoenebeck	53	pStreamRef->State = Stream::state_active;
120	senkov	329	pStreamRef->OrderID = newOrder;
121	schoenebeck	53	pStreamRef->hStream = CreateHandle();
122			pStreamRef->pStream = NULL; // a stream has to be activated by the disk thread first
123
124			create_command_t cmd;
125			cmd.OrderID = pStreamRef->OrderID;
126			cmd.hStream = pStreamRef->hStream;
127			cmd.pStreamRef = pStreamRef;
128			cmd.pSample = pSample;
129			cmd.SampleOffset = SampleOffset;
130			cmd.DoLoop = DoLoop;
131
132			CreationQueue->push(&cmd);
133			return 0;
134			}
135
136			/**
137			* Returns -1 if command queue is full, 0 on success (will be called by audio
138			* thread within the voice class).
139			*/
140			int DiskThread::OrderDeletionOfStream(Stream::reference_t* pStreamRef) {
141			dmsg(4,("Disk Thread: stream deletion ordered\n"));
142			if (DeletionQueue->write_space() < 1) {
143			dmsg(1,("DiskThread: Deletion queue full!\n"));
144			return -1;
145			}
146
147			delete_command_t cmd;
148			cmd.pStream = pStreamRef->pStream;
149			cmd.hStream = pStreamRef->hStream;
150			cmd.OrderID = pStreamRef->OrderID;
151
152			DeletionQueue->push(&cmd);
153			return 0;
154			}
155
156			/**
157			* Returns the pointer to a disk stream if the ordered disk stream
158			* represented by the \a StreamOrderID was already activated by the disk
159			* thread, returns NULL otherwise. If the call was successful, thus if it
160			* returned a valid stream pointer, the caller has to the store that pointer
161			* by himself, because it's not possible to call this method again with the
162			* same used order ID; this method is just intended for picking up an ordered
163			* disk stream. This method will usually be called by the voice class (within
164			* the audio thread).
165			*
166			* @param StreamOrderID - ID previously returned by OrderNewStream()
167			* @returns pointer to created stream object, NULL otherwise
168			*/
169			Stream* DiskThread::AskForCreatedStream(Stream::OrderID_t StreamOrderID) {
170			dmsg(4,("Disk Thread: been asked if stream already created, OrderID=%x ", StreamOrderID));
171			Stream* pStream = pCreatedStreams[StreamOrderID];
172			if (pStream && pStream != SLOT_RESERVED) {
173			dmsg(4,("(yes created)\n"));
174			pCreatedStreams[StreamOrderID] = NULL; // free the slot for a new order
175			return pStream;
176			}
177			dmsg(4,("(no not yet created)\n"));
178			return NULL;
179			}
180
181
182
183			// #########################################################################
184			// # Disk Thread Only Section
185			// # (following code should only be executed by the disk thread)
186
187
188	schoenebeck	392	DiskThread::DiskThread(uint BufferWrapElements) : Thread(true, false, 1, -2) {
189	schoenebeck	385	DecompressionBuffer = ::gig::Sample::CreateDecompressionBuffer(MAX_REFILL_SIZE);
190	schoenebeck	53	CreationQueue = new RingBuffer<create_command_t>(1024);
191			DeletionQueue = new RingBuffer<delete_command_t>(1024);
192			GhostQueue = new RingBuffer<Stream::Handle>(MAX_INPUT_STREAMS);
193			Streams = MAX_INPUT_STREAMS;
194			RefillStreamsPerRun = REFILL_STREAMS_PER_RUN;
195			for (int i = 0; i < MAX_INPUT_STREAMS; i++) {
196	schoenebeck	385	pStreams[i] = new Stream(&DecompressionBuffer, STREAM_BUFFER_SIZE, BufferWrapElements); // 131072 sample words
197	schoenebeck	53	}
198			for (int i = 1; i <= MAX_INPUT_STREAMS; i++) {
199			pCreatedStreams[i] = NULL;
200			}
201			}
202
203			DiskThread::~DiskThread() {
204			for (int i = 0; i < MAX_INPUT_STREAMS; i++) {
205			if (pStreams[i]) delete pStreams[i];
206			}
207			if (CreationQueue) delete CreationQueue;
208			if (DeletionQueue) delete DeletionQueue;
209			if (GhostQueue) delete GhostQueue;
210	schoenebeck	385	::gig::Sample::DestroyDecompressionBuffer(DecompressionBuffer);
211	schoenebeck	53	}
212
213			int DiskThread::Main() {
214			dmsg(3,("Disk thread running\n"));
215			while (true) {
216	schoenebeck	361	pthread_testcancel(); // mandatory for OSX
217	schoenebeck	53	IsIdle = true; // will be set to false if a stream got filled
218
219			// if there are ghost streams, delete them
220			for (int i = 0; i < GhostQueue->read_space(); i++) { //FIXME: unefficient
221			Stream::Handle hGhostStream;
222			GhostQueue->pop(&hGhostStream);
223			bool found = false;
224			for (int i = 0; i < this->Streams; i++) {
225			if (pStreams[i]->GetHandle() == hGhostStream) {
226			pStreams[i]->Kill();
227			found = true;
228			break;
229			}
230			}
231			if (!found) GhostQueue->push(&hGhostStream); // put ghost stream handle back to the queue
232			}
233
234			// if there are creation commands, create new streams
235			while (Stream::UnusedStreams > 0 && CreationQueue->read_space() > 0) {
236			create_command_t command;
237			CreationQueue->pop(&command);
238			CreateStream(command);
239			}
240
241			// if there are deletion commands, delete those streams
242	senkov	333	while (Stream::UnusedStreams < Stream::TotalStreams && DeletionQueue->read_space() > 0) {
243	schoenebeck	53	delete_command_t command;
244			DeletionQueue->pop(&command);
245			DeleteStream(command);
246			}
247
248			RefillStreams(); // refill the most empty streams
249
250			// if nothing was done during this iteration (eg no streambuffer
251			// filled with data) then sleep for 50ms
252			if (IsIdle) usleep(30000);
253
254			int streamsInUsage = 0;
255			for (int i = Streams - 1; i >= 0; i--) {
256			if (pStreams[i]->GetState() != Stream::state_unused) streamsInUsage++;
257			}
258			ActiveStreamCount = streamsInUsage;
259			if (streamsInUsage > ActiveStreamCountMax) ActiveStreamCountMax = streamsInUsage;
260			}
261
262			return EXIT_FAILURE;
263			}
264
265			void DiskThread::CreateStream(create_command_t& Command) {
266			// search for unused stream
267			Stream* newstream = NULL;
268			for (int i = Streams - 1; i >= 0; i--) {
269			if (pStreams[i]->GetState() == Stream::state_unused) {
270			newstream = pStreams[i];
271			break;
272			}
273			}
274			if (!newstream) {
275			std::cerr << "No unused stream found (OrderID:" << Command.OrderID << ") - report if this happens, this is a bug!\n" << std::flush;
276			return;
277			}
278			newstream->Launch(Command.hStream, Command.pStreamRef, Command.pSample, Command.SampleOffset, Command.DoLoop);
279			dmsg(4,("new Stream launched by disk thread (OrderID:%d,StreamHandle:%d)\n", Command.OrderID, Command.hStream));
280			if (pCreatedStreams[Command.OrderID] != SLOT_RESERVED) {
281			std::cerr << "DiskThread: Slot " << Command.OrderID << " already occupied! Please report this!\n" << std::flush;
282			newstream->Kill();
283			return;
284			}
285			pCreatedStreams[Command.OrderID] = newstream;
286			}
287
288			void DiskThread::DeleteStream(delete_command_t& Command) {
289			if (Command.pStream) Command.pStream->Kill();
290			else { // the stream wasn't created by disk thread or picked up by audio thread yet
291
292			// if stream was created but not picked up yet
293			Stream* pStream = pCreatedStreams[Command.OrderID];
294			if (pStream && pStream != SLOT_RESERVED) {
295			pStream->Kill();
296			pCreatedStreams[Command.OrderID] = NULL; // free slot for new order
297			return;
298			}
299
300			// the stream was not created yet
301			if (GhostQueue->write_space() > 0) {
302			GhostQueue->push(&Command.hStream);
303			}
304			else dmsg(1,("DiskThread: GhostQueue full!\n"));
305			}
306			}
307
308			void DiskThread::RefillStreams() {
309			// sort the streams by most empty stream
310			qsort(pStreams, Streams, sizeof(Stream*), CompareStreamWriteSpace);
311
312			// refill the most empty streams
313			for (uint i = 0; i < RefillStreamsPerRun; i++) {
314			if (pStreams[i]->GetState() == Stream::state_active) {
315
316			//float filledpercentage = (float) pStreams[i]->GetReadSpace() / 131072.0 * 100.0;
317			//dmsg(("\nbuffer fill: %.1f%\n", filledpercentage));
318
319			int writespace = pStreams[i]->GetWriteSpaceToEnd();
320			if (writespace == 0) break;
321
322			int capped_writespace = writespace;
323			// if there is too much buffer space available then cut the read/write
324			// size to MAX_REFILL_SIZE which is by default 65536 samples = 256KBytes
325			if (writespace > MAX_REFILL_SIZE) capped_writespace = MAX_REFILL_SIZE;
326
327			// adjust the amount to read in order to ensure that the buffer wraps correctly
328			int read_amount = pStreams[i]->AdjustWriteSpaceToAvoidBoundary(writespace, capped_writespace);
329			// if we wasn't able to refill one of the stream buffers by more than
330			// MIN_REFILL_SIZE we'll send the disk thread to sleep later
331			if (pStreams[i]->ReadAhead(read_amount) > MIN_REFILL_SIZE) this->IsIdle = false;
332			}
333			}
334			}
335
336			/// Handle Generator
337			Stream::Handle DiskThread::CreateHandle() {
338			static uint32_t counter = 0;
339			if (counter == 0xffffffff) counter = 1; // we use '0' as 'invalid handle' only, so we skip 0
340			else counter++;
341			return counter;
342			}
343
344			/// order ID Generator
345			Stream::OrderID_t DiskThread::CreateOrderID() {
346	senkov	329	static Stream::OrderID_t counter(0);
347	schoenebeck	53	for (int i = 0; i < MAX_INPUT_STREAMS; i++) {
348			if (counter == MAX_INPUT_STREAMS) counter = 1; // we use '0' as 'invalid order' only, so we skip 0
349			else counter++;
350			if (!pCreatedStreams[counter]) {
351			pCreatedStreams[counter] = SLOT_RESERVED; // mark this slot as reserved
352			return counter; // found empty slot
353			}
354			}
355			return 0; // no free slot
356			}
357
358
359
360			// ********* C functions ************
361			// *
362
363			/**
364			* This is the comparison function the qsort algo uses to determine if a value is
365			* bigger than another one or special in our case; if the writespace of a stream
366			* is bigger than another one.
367			*/
368			int CompareStreamWriteSpace(const void* A, const void* B) {
369			Stream* a = (Stream*) A;
370			Stream* b = (Stream*) B;
371			return b->GetWriteSpace() - a->GetWriteSpace();
372			}
373
374			}} // namespace LinuxSampler::gig