Question

I’m currently creating a sound system for my project. Every call PlayAsync creating instance of sound in std::thread callback. The sound data proceed in cycle in this callback. When thread proceeds it store sound instance in static vector. When thread ends (sound complete) – it delete sound instance and decrement instance count. When application ends – it must stop all sounds immediate, sending interrupt to every cycle of sound.

The problem is in array keeping these sounds. I am not sure, but I think vector isn’t right choice for this purpose.. Here is a code.

void gSound::PlayAsync()
{
    std::thread t(gSound::Play,mp_Audio,std::ref(*this));
    t.detach();
}
    HRESULT gSound::Play(IXAudio2* s_XAudio,gSound& sound)
{                
    gSound* pSound = new gSound(sound);   
    pSound->m_Disposed = false;         

    HRESULT hr;      
    // Create the source voice
    IXAudio2SourceVoice* pSourceVoice;
    if( FAILED( hr = s_XAudio->CreateSourceVoice( &pSourceVoice, pSound->pwfx ) ) )
    {
        gDebug::ShowMessage(L"Error creating source voice");      
        return hr;
    }

    // Submit the wave sample data using an XAUDIO2_BUFFER structure
    XAUDIO2_BUFFER buffer = {0};
    buffer.pAudioData = pSound->pbWaveData;
    buffer.Flags = XAUDIO2_END_OF_STREAM;  // tell the source voice not to expect any data after this buffer
    buffer.AudioBytes = pSound->cbWaveSize;

    if( FAILED( hr = pSourceVoice->SubmitSourceBuffer( &buffer ) ) )
    {
        gDebug::ShowMessage(L"Error submitting source buffer");
        pSourceVoice->DestroyVoice();   
        return hr;
    }

    hr = pSourceVoice->Start( 0 );     

    // Let the sound play
    BOOL isRunning = TRUE;
    m_soundInstanceCount++;     
    mp_SoundInstances.push_back(pSound); #MARK2
    while( SUCCEEDED( hr ) && isRunning && pSourceVoice != nullptr && !pSound->m_Interrupted)
    {    
        XAUDIO2_VOICE_STATE state;
        pSourceVoice->GetState( &state );
        isRunning = ( state.BuffersQueued > 0 ) != 0;     
        Sleep(10);
    }   
    pSourceVoice->DestroyVoice();   
    delete pSound;pSound = nullptr; //its correct ??
    m_soundInstanceCount--; 
    return 0;    
}

void gSound::InterrupAllSoundInstances()
{
    for(auto Iter = mp_SoundInstances.begin(); Iter != mp_SoundInstances.end(); Iter++)
    {
        if(*Iter != nullptr)//#MARK1
        {
        (*Iter)->m_Interrupted = true;
        }
    }
}

And this I call in application class before disposing sound objects, after main application loop immediate.

    gSound::InterrupAllSoundInstances();
while (gSound::m_soundInstanceCount>0)//waiting for deleting all sound instances in threads
{

}

Questions:

So #MARK1 – How to check memory validation in vector? I don’t have experience about it. And get errors when try check invalid memory (it’s not equals null)

And #MARK2 – How to use vector correctly? Or maybe vector is bad choice? Every time I create sound instance it increases size. It’s not good.

Answer 1

A typical issue:

delete pSound;
pSound = nullptr; // issue

This does not do what you think.

It will effectively set pSound to null, but there are other copies of the same pointer too (at least one in the vector) which do not get nullified. This is why you do not find nullptr in your vector.

Instead you could register the index into the vector and nullify that: mp_SoundInstances[index] = nullptr;.

However, I am afraid that you simply do not understand memory handling well and you lack structure. For memory handling, it’s hard to tell without details and your system seems complicated enough that I am afraid it would tell too long to explain. For structure, you should read a bit about the Observer pattern.