cdrom/macosx/AudioFileReaderThread.c

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2012 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken (at) libsdl.org

    This file based on Apple sample code. We haven't changed the file name,
    so if you want to see the original search for it on apple.com/developer
*/
#include "SDL_config.h"

/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   AudioFileManager.cpp
*/
#include "AudioFilePlayer.h"
#include <mach/mach.h> /* used for setting policy of thread */
#include "SDLOSXCAGuard.h"
#include <pthread.h>

/*#include <list>*/

/*typedef void *FileData;*/
typedef struct S_FileData
{
    AudioFileManager *obj;
    struct S_FileData *next;
} FileData;


typedef struct S_FileReaderThread {
/*public:*/
    SDLOSXCAGuard*                    (*GetGuard)(struct S_FileReaderThread *frt);
    void                        (*AddReader)(struct S_FileReaderThread *frt);
    void                        (*RemoveReader)(struct S_FileReaderThread *frt, AudioFileManager* inItem);
    int                         (*TryNextRead)(struct S_FileReaderThread *frt, AudioFileManager* inItem);

    int     mThreadShouldDie;

/*private:*/
    /*typedef std::list<AudioFileManager*> FileData;*/

    SDLOSXCAGuard             *mGuard;
    UInt32              mThreadPriority;

    int                 mNumReaders;
    FileData            *mFileData;


    void                        (*ReadNextChunk)(struct S_FileReaderThread *frt);
    int                         (*StartFixedPriorityThread)(struct S_FileReaderThread *frt);
    /*static*/
    UInt32               (*GetThreadBasePriority)(pthread_t inThread);
    /*static*/
    void*                (*DiskReaderEntry)(void *inRefCon);
} FileReaderThread;


static SDLOSXCAGuard* FileReaderThread_GetGuard(FileReaderThread *frt)
{
    return frt->mGuard;
}

/* returns 1 if succeeded */
static int FileReaderThread_TryNextRead (FileReaderThread *frt, AudioFileManager* inItem)
{
    int didLock = 0;
    int succeeded = 0;
    if (frt->mGuard->Try(frt->mGuard, &didLock))
    {
        /*frt->mFileData.push_back (inItem);*/
        /* !!! FIXME: this could be faster with a "tail" member. --ryan. */
        FileData *i = frt->mFileData;
        FileData *prev = NULL;

        FileData *newfd = (FileData *) SDL_malloc(sizeof (FileData));
        newfd->obj = inItem;
        newfd->next = NULL;

        while (i != NULL) { prev = i; i = i->next; }
        if (prev == NULL)
            frt->mFileData = newfd;
        else
            prev->next = newfd;

        frt->mGuard->Notify(frt->mGuard);
        succeeded = 1;

        if (didLock)
            frt->mGuard->Unlock(frt->mGuard);
    }

    return succeeded;
}

static void    FileReaderThread_AddReader(FileReaderThread *frt)
{
    if (frt->mNumReaders == 0)
    {
        frt->mThreadShouldDie = 0;
        frt->StartFixedPriorityThread (frt);
    }
    frt->mNumReaders++;
}

static void    FileReaderThread_RemoveReader (FileReaderThread *frt, AudioFileManager* inItem)
{
    if (frt->mNumReaders > 0)
    {
        int bNeedsRelease = frt->mGuard->Lock(frt->mGuard);

        /*frt->mFileData.remove (inItem);*/
        FileData *i = frt->mFileData;
        FileData *prev = NULL;
        while (i != NULL)
        {
            FileData *next = i->next;
            if (i->obj != inItem)
                prev = i;
            else
            {
                if (prev == NULL)
                    frt->mFileData = next;
                else
                    prev->next = next;
                SDL_free(i);
            }
            i = next;
        }

        if (--frt->mNumReaders == 0) {
            frt->mThreadShouldDie = 1;
            frt->mGuard->Notify(frt->mGuard); /* wake up thread so it will quit */
            frt->mGuard->Wait(frt->mGuard);   /* wait for thread to die */
        }

        if (bNeedsRelease) frt->mGuard->Unlock(frt->mGuard);
    }
}

static int    FileReaderThread_StartFixedPriorityThread (FileReaderThread *frt)
{
    pthread_attr_t      theThreadAttrs;
    pthread_t           pThread;

    OSStatus result = pthread_attr_init(&theThreadAttrs);
        if (result) return 0; /*THROW_RESULT("pthread_attr_init - Thread attributes could not be created.")*/

    result = pthread_attr_setdetachstate(&theThreadAttrs, PTHREAD_CREATE_DETACHED);
        if (result) return 0; /*THROW_RESULT("pthread_attr_setdetachstate - Thread attributes could not be detached.")*/

    result = pthread_create (&pThread, &theThreadAttrs, frt->DiskReaderEntry, frt);
        if (result) return 0; /*THROW_RESULT("pthread_create - Create and start the thread.")*/

    pthread_attr_destroy(&theThreadAttrs);

    /* we've now created the thread and started it
       we'll now set the priority of the thread to the nominated priority
       and we'll also make the thread fixed */
    thread_extended_policy_data_t       theFixedPolicy;
    thread_precedence_policy_data_t     thePrecedencePolicy;
    SInt32                              relativePriority;

    /* make thread fixed */
    theFixedPolicy.timeshare = 0;   /* set to 1 for a non-fixed thread */
    result = thread_policy_set (pthread_mach_thread_np(pThread), THREAD_EXTENDED_POLICY, (thread_policy_t)&theFixedPolicy, THREAD_EXTENDED_POLICY_COUNT);
        if (result) return 0; /*THROW_RESULT("thread_policy - Couldn't set thread as fixed priority.")*/
    /* set priority */
    /* precedency policy's "importance" value is relative to spawning thread's priority */
    relativePriority = frt->mThreadPriority - frt->GetThreadBasePriority(pthread_self());

    thePrecedencePolicy.importance = relativePriority;
    result = thread_policy_set (pthread_mach_thread_np(pThread), THREAD_PRECEDENCE_POLICY, (thread_policy_t)&thePrecedencePolicy, THREAD_PRECEDENCE_POLICY_COUNT);
        if (result) return 0; /*THROW_RESULT("thread_policy - Couldn't set thread priority.")*/

    return 1;
}

static UInt32  FileReaderThread_GetThreadBasePriority (pthread_t inThread)
{
    thread_basic_info_data_t            threadInfo;
    policy_info_data_t                  thePolicyInfo;
    unsigned int                        count;

    /* get basic info */
    count = THREAD_BASIC_INFO_COUNT;
    thread_info (pthread_mach_thread_np (inThread), THREAD_BASIC_INFO, (integer_t*)&threadInfo, &count);

    switch (threadInfo.policy) {
        case POLICY_TIMESHARE:
            count = POLICY_TIMESHARE_INFO_COUNT;
            thread_info(pthread_mach_thread_np (inThread), THREAD_SCHED_TIMESHARE_INFO, (integer_t*)&(thePolicyInfo.ts), &count);
            return thePolicyInfo.ts.base_priority;
            break;

        case POLICY_FIFO:
            count = POLICY_FIFO_INFO_COUNT;
            thread_info(pthread_mach_thread_np (inThread), THREAD_SCHED_FIFO_INFO, (integer_t*)&(thePolicyInfo.fifo), &count);
            if (thePolicyInfo.fifo.depressed) {
                return thePolicyInfo.fifo.depress_priority;
            } else {
                return thePolicyInfo.fifo.base_priority;
            }
            break;

        case POLICY_RR:
            count = POLICY_RR_INFO_COUNT;
            thread_info(pthread_mach_thread_np (inThread), THREAD_SCHED_RR_INFO, (integer_t*)&(thePolicyInfo.rr), &count);
            if (thePolicyInfo.rr.depressed) {
                return thePolicyInfo.rr.depress_priority;
            } else {
                return thePolicyInfo.rr.base_priority;
            }
            break;
    }

    return 0;
}

static void    *FileReaderThread_DiskReaderEntry (void *inRefCon)
{
    FileReaderThread *frt = (FileReaderThread *)inRefCon;
    frt->ReadNextChunk(frt);
    #if DEBUG
    printf ("finished with reading file\n");
    #endif

    return 0;
}

static void    FileReaderThread_ReadNextChunk (FileReaderThread *frt)
{
    OSStatus result;
    ByteCount dataChunkSize;
    AudioFileManager* theItem = 0;

    for (;;)
    {
        { /* this is a scoped based lock */
            int bNeedsRelease = frt->mGuard->Lock(frt->mGuard);

            if (frt->mThreadShouldDie) {
                frt->mGuard->Notify(frt->mGuard);
                if (bNeedsRelease) frt->mGuard->Unlock(frt->mGuard);
                return;
            }

            /*if (frt->mFileData.empty())*/
            if (frt->mFileData == NULL)
            {
                frt->mGuard->Wait(frt->mGuard);
            }

            /* kill thread */
            if (frt->mThreadShouldDie) {

                frt->mGuard->Notify(frt->mGuard);
                if (bNeedsRelease) frt->mGuard->Unlock(frt->mGuard);
                return;
            }

            /*theItem = frt->mFileData.front();*/
            /*frt->mFileData.pop_front();*/
            theItem = NULL;
            if (frt->mFileData != NULL)
            {
                FileData *next = frt->mFileData->next;
                theItem = frt->mFileData->obj;
                SDL_free(frt->mFileData);
                frt->mFileData = next;
            }

            if (bNeedsRelease) frt->mGuard->Unlock(frt->mGuard);
        }

        if ((theItem->mFileLength - theItem->mReadFilePosition) < theItem->mChunkSize)
            dataChunkSize = theItem->mFileLength - theItem->mReadFilePosition;
        else
            dataChunkSize = theItem->mChunkSize;

            /* this is the exit condition for the thread */
        if (dataChunkSize <= 0) {
            theItem->mFinishedReadingData = 1;
            continue;
        }
            /* construct pointer */
        char* writePtr = (char *) (theItem->GetFileBuffer(theItem) +
                                (theItem->mWriteToFirstBuffer ? 0 : theItem->mChunkSize));

            /* read data */
        result = theItem->Read(theItem, writePtr, &dataChunkSize);
        if (result != noErr && result != eofErr) {
            AudioFilePlayer *afp = (AudioFilePlayer *) theItem->GetParent(theItem);
            afp->DoNotification(afp, result);
            continue;
        }

        if (dataChunkSize != theItem->mChunkSize)
        {
            writePtr += dataChunkSize;

            /* can't exit yet.. we still have to pass the partial buffer back */
            SDL_memset(writePtr, 0, (theItem->mChunkSize - dataChunkSize));
        }

        theItem->mWriteToFirstBuffer = !theItem->mWriteToFirstBuffer;   /* switch buffers */

        if (result == eofErr)
            theItem->mReadFilePosition = theItem->mFileLength;
        else
            theItem->mReadFilePosition += dataChunkSize;        /* increment count */
    }
}

void delete_FileReaderThread(FileReaderThread *frt)
{
    if (frt != NULL)
    {
        delete_SDLOSXCAGuard(frt->mGuard);
        SDL_free(frt);
    }
}

FileReaderThread *new_FileReaderThread ()
{
    FileReaderThread *frt = (FileReaderThread *) SDL_malloc(sizeof (FileReaderThread));
    if (frt == NULL)
        return NULL;
    SDL_memset(frt, '\0', sizeof (*frt));

    frt->mGuard = new_SDLOSXCAGuard();
    if (frt->mGuard == NULL)
    {
        SDL_free(frt);
        return NULL;
    }

    #define SET_FILEREADERTHREAD_METHOD(m) frt->m = FileReaderThread_##m
    SET_FILEREADERTHREAD_METHOD(GetGuard);
    SET_FILEREADERTHREAD_METHOD(AddReader);
    SET_FILEREADERTHREAD_METHOD(RemoveReader);
    SET_FILEREADERTHREAD_METHOD(TryNextRead);
    SET_FILEREADERTHREAD_METHOD(ReadNextChunk);
    SET_FILEREADERTHREAD_METHOD(StartFixedPriorityThread);
    SET_FILEREADERTHREAD_METHOD(GetThreadBasePriority);
    SET_FILEREADERTHREAD_METHOD(DiskReaderEntry);
    #undef SET_FILEREADERTHREAD_METHOD

    frt->mThreadPriority = 62;
    return frt;
}


static FileReaderThread *sReaderThread;


static int    AudioFileManager_DoConnect (AudioFileManager *afm)
{
    if (!afm->mIsEngaged)
    {
        OSStatus result;

        /*afm->mReadFilePosition = 0;*/
        afm->mFinishedReadingData = 0;

        afm->mNumTimesAskedSinceFinished = 0;
        afm->mLockUnsuccessful = 0;

        ByteCount dataChunkSize;

        if ((afm->mFileLength - afm->mReadFilePosition) < afm->mChunkSize)
            dataChunkSize = afm->mFileLength - afm->mReadFilePosition;
        else
            dataChunkSize = afm->mChunkSize;

        result = afm->Read(afm, afm->mFileBuffer, &dataChunkSize);
           if (result) return 0; /*THROW_RESULT("AudioFileManager::DoConnect(): Read")*/

        afm->mReadFilePosition += dataChunkSize;

        afm->mWriteToFirstBuffer = 0;
        afm->mReadFromFirstBuffer = 1;

        sReaderThread->AddReader(sReaderThread);

        afm->mIsEngaged = 1;
    }
    /*
    else
        throw static_cast<OSStatus>(-1); */ /* thread has already been started */

    return 1;
}

static void    AudioFileManager_Disconnect (AudioFileManager *afm)
{
    if (afm->mIsEngaged)
    {
        sReaderThread->RemoveReader (sReaderThread, afm);
        afm->mIsEngaged = 0;
    }
}

static OSStatus AudioFileManager_Read(AudioFileManager *afm, char *buffer, ByteCount *len)
{
    return FSReadFork (afm->mForkRefNum,
                       fsFromStart,
                       afm->mReadFilePosition + afm->mAudioDataOffset,
                       *len,
                       buffer,
                       len);
}

static OSStatus AudioFileManager_GetFileData (AudioFileManager *afm, void** inOutData, UInt32 *inOutDataSize)
{
    if (afm->mFinishedReadingData)
    {
        ++afm->mNumTimesAskedSinceFinished;
        *inOutDataSize = 0;
        *inOutData = 0;
        return noErr;
    }

    if (afm->mReadFromFirstBuffer == afm->mWriteToFirstBuffer) {
        #if DEBUG
        printf ("* * * * * * * Can't keep up with reading file\n");
        #endif

        afm->mParent->DoNotification (afm->mParent, kAudioFilePlayErr_FilePlayUnderrun);
        *inOutDataSize = 0;
        *inOutData = 0;
    } else {
        *inOutDataSize = afm->mChunkSize;
        *inOutData = afm->mReadFromFirstBuffer ? afm->mFileBuffer : (afm->mFileBuffer + afm->mChunkSize);
    }

    afm->mLockUnsuccessful = !sReaderThread->TryNextRead (sReaderThread, afm);

    afm->mReadFromFirstBuffer = !afm->mReadFromFirstBuffer;

    return noErr;
}

static void    AudioFileManager_AfterRender (AudioFileManager *afm)
{
    if (afm->mNumTimesAskedSinceFinished > 0)
    {
        int didLock = 0;
        SDLOSXCAGuard *guard = sReaderThread->GetGuard(sReaderThread);
        if (guard->Try(guard, &didLock)) {
            afm->mParent->DoNotification (afm->mParent, kAudioFilePlay_FileIsFinished);
            if (didLock)
                guard->Unlock(guard);
        }
    }

    if (afm->mLockUnsuccessful)
        afm->mLockUnsuccessful = !sReaderThread->TryNextRead (sReaderThread, afm);
}

static void    AudioFileManager_SetPosition (AudioFileManager *afm, SInt64 pos)
{
    if (pos < 0 || pos >= afm->mFileLength) {
        SDL_SetError ("AudioFileManager::SetPosition - position invalid: %d filelen=%d\n",
            (unsigned int)pos, (unsigned int)afm->mFileLength);
        pos = 0;
    }

    afm->mReadFilePosition = pos;
}

static void    AudioFileManager_SetEndOfFile (AudioFileManager *afm, SInt64 pos)
{
    if (pos <= 0 || pos > afm->mFileLength) {
        SDL_SetError ("AudioFileManager::SetEndOfFile - position beyond actual eof\n");
        pos = afm->mFileLength;
    }

    afm->mFileLength = pos;
}

static const char *AudioFileManager_GetFileBuffer(AudioFileManager *afm)
{
    return afm->mFileBuffer;
}

const AudioFilePlayer *AudioFileManager_GetParent(AudioFileManager *afm)
{
    return afm->mParent;
}

static int AudioFileManager_GetByteCounter(AudioFileManager *afm)
{
    return afm->mByteCounter;
}

static OSStatus    AudioFileManager_FileInputProc (void                  *inRefCon,
                                         AudioUnitRenderActionFlags      *ioActionFlags,
                                         const AudioTimeStamp            *inTimeStamp,
                                         UInt32                          inBusNumber,
                                         UInt32                          inNumberFrames,
                                         AudioBufferList                 *ioData)
{
    AudioFileManager* afm = (AudioFileManager*)inRefCon;
    return afm->Render(afm, ioData);
}

static OSStatus    AudioFileManager_Render (AudioFileManager *afm, AudioBufferList *ioData)
{
    OSStatus result = noErr;
    AudioBuffer *abuf;
    UInt32 i;

    for (i = 0; i < ioData->mNumberBuffers; i++) {
        abuf = &ioData->mBuffers[i];
        if (afm->mBufferOffset >= afm->mBufferSize) {
            result = afm->GetFileData(afm, &afm->mTmpBuffer, &afm->mBufferSize);
            if (result) {
                SDL_SetError ("AudioConverterFillBuffer:%ld\n", result);
                afm->mParent->DoNotification(afm->mParent, result);
                return result;
            }

            afm->mBufferOffset = 0;
        }

        if (abuf->mDataByteSize > afm->mBufferSize - afm->mBufferOffset)
            abuf->mDataByteSize = afm->mBufferSize - afm->mBufferOffset;
        abuf->mData = (char *)afm->mTmpBuffer + afm->mBufferOffset;
        afm->mBufferOffset += abuf->mDataByteSize;

        afm->mByteCounter += abuf->mDataByteSize;
        afm->AfterRender(afm);
    }
    return result;
}


void delete_AudioFileManager (AudioFileManager *afm)
{
    if (afm != NULL) {
        if (afm->mFileBuffer) {
            free(afm->mFileBuffer);
        }

        SDL_free(afm);
    }
}


AudioFileManager *new_AudioFileManager(AudioFilePlayer *inParent,
                                       SInt16          inForkRefNum,
                                       SInt64          inFileLength,
                                       UInt32          inChunkSize)
{
    AudioFileManager *afm;

    if (sReaderThread == NULL)
    {
        sReaderThread = new_FileReaderThread();
        if (sReaderThread == NULL)
            return NULL;
    }

    afm = (AudioFileManager *) SDL_malloc(sizeof (AudioFileManager));
    if (afm == NULL)
        return NULL;
    SDL_memset(afm, '\0', sizeof (*afm));

    #define SET_AUDIOFILEMANAGER_METHOD(m) afm->m = AudioFileManager_##m
    SET_AUDIOFILEMANAGER_METHOD(Disconnect);
    SET_AUDIOFILEMANAGER_METHOD(DoConnect);
    SET_AUDIOFILEMANAGER_METHOD(Read);
    SET_AUDIOFILEMANAGER_METHOD(GetFileBuffer);
    SET_AUDIOFILEMANAGER_METHOD(GetParent);
    SET_AUDIOFILEMANAGER_METHOD(SetPosition);
    SET_AUDIOFILEMANAGER_METHOD(GetByteCounter);
    SET_AUDIOFILEMANAGER_METHOD(SetEndOfFile);
    SET_AUDIOFILEMANAGER_METHOD(Render);
    SET_AUDIOFILEMANAGER_METHOD(GetFileData);
    SET_AUDIOFILEMANAGER_METHOD(AfterRender);
    SET_AUDIOFILEMANAGER_METHOD(FileInputProc);
    #undef SET_AUDIOFILEMANAGER_METHOD

    afm->mParent = inParent;
    afm->mForkRefNum = inForkRefNum;
    afm->mBufferSize = inChunkSize;
    afm->mBufferOffset = inChunkSize;
    afm->mChunkSize = inChunkSize;
    afm->mFileLength = inFileLength;
    afm->mFileBuffer = (char*) SDL_malloc(afm->mChunkSize * 2);
    FSGetForkPosition(afm->mForkRefNum, &afm->mAudioDataOffset);
    assert (afm->mFileBuffer != NULL);
    return afm;
}