[PATCH 5/6] amstream: Implement audio stream sample Update.

[Anton Baskanov]

Hello Zeb, thanks for the comments, I've replied inline.

On 4/20/20 5:07 AM, you wrote:
> Hello Anton, nice work on the patch! It mostly looks good to me; I have
> some comments and questions inlined.
> 
> On 4/18/20 9:34 AM, Anton Baskanov wrote:
> > +static void process_update(IAudioStreamSampleImpl *sample, struct
> > queued_event *event) +{
> > +    DWORD advance;
> > +
> > +    if (event->type == QET_END_OF_STREAM)
> > +    {
> > +        sample->update_hr = sample->position ? S_OK : MS_S_ENDOFSTREAM;
> > +        return;
> > +    }
> > +
> > +    advance = min(event->length - event->position, sample->length -
> > sample->position); +    CopyMemory(&sample->pointer[sample->position],
> > &event->pointer[event->position], advance);
> memcpy()?
> 

Done.

> > +
> > +    event->position += advance;
> > +    sample->position += advance;
> > +
> > +    sample->update_hr = (sample->position == sample->length) ? S_OK :
> > MS_S_PENDING; +}
> > +
> > +static void process_updates(struct audio_stream *stream)
> > +{
> > +    while (!list_empty(&stream->update_queue) &&
> > !list_empty(&stream->event_queue)) +    {
> > +        IAudioStreamSampleImpl *sample =
> > LIST_ENTRY(list_head(&stream->update_queue), IAudioStreamSampleImpl,
> > entry); +        struct queued_event *event =
> > LIST_ENTRY(list_head(&stream->event_queue), struct queued_event, entry);
> > +
> > +        process_update(sample, event);
> > +
> > +        if (MS_S_PENDING != sample->update_hr)
> > +            remove_queued_update(sample);
> > +        if ((event->type != QET_END_OF_STREAM) && (event->position ==
> > event->length)) +            remove_queued_event(event);
> 
> It kind of feels weird to me to queue EOS events the same way as
> samples, given they apply to all streams at once, can't be interleaved,
> can't be sent multiple times, and don't get removed from the queue until
> the stream is stopped (or flushed, presumably?).
> 
> Maybe it would be clearer not to queue EOS events at all, but instead to
> loop through all queued samples in audio_sink_EndOfStream(), completing
> them with MS_E_ENDOFSTREAM, and similarly to check for stream->eos in
> process_updates(). I imagine you could get rid of the queued_event_type
> enumeration then, unless there's another kind of event that I'm not
> anticipating?
> 

Queuing EOS events is actually the correct way of doing things, otherwise the 
final samples would get lost. Consider the following scenario:

Receive()
EndOfStream()
Update() -> S_OK
Update() -> MS_S_ENDOFSTREAM

It is expected that Update retrieves all available data before returning 
MS_S_ENDOFSTREAM. The tests confirm this behavior.

> > +    }
> > +}
> > +
> > 
> >  static inline struct audio_stream
> >  *impl_from_IAMMediaStream(IAMMediaStream *iface) {
> >  
> >      return CONTAINING_RECORD(iface, struct audio_stream,
> >      IAMMediaStream_iface);
> > 
> > @@ -449,6 +503,85 @@ static inline struct audio_stream
> > *impl_from_IAudioMediaStream(IAudioMediaStream> 
> >      return CONTAINING_RECORD(iface, struct audio_stream,
> >      IAudioMediaStream_iface);>  
> >  }
> > 
> > +static HRESULT WINAPI IAudioStreamSampleImpl_Update(IAudioStreamSample
> > *iface, DWORD flags, HANDLE event, +        PAPCFUNC func_APC, DWORD
> > APC_data)
> > +{
> > +    IAudioStreamSampleImpl *sample = impl_from_IAudioStreamSample(iface);
> > +    struct audio_stream *stream;
> > +    DWORD length;
> > +    BYTE *pointer;
> > +    HRESULT hr;
> > +
> > +    TRACE("(%p)->(%x,%p,%p,%u)\n", iface, flags, event, func_APC,
> > APC_data); +
> > +    stream = impl_from_IAudioMediaStream(sample->parent);
> 
> Perhaps easier would be to take patch 2/6 a step further and store
> sample->parent as a pointer to struct audio_stream. Then you wouldn't
> need to move this function out of place.
> 

Done.

> > +
> > +    hr = IAudioData_GetInfo(sample->audio_data, &length, &pointer, NULL);
> > +    if (FAILED(hr))
> > +        return hr;
> > +
> > +    if (event && func_APC)
> > +        return E_INVALIDARG;
> > +
> > +    if (func_APC)
> > +    {
> > +        FIXME("APC support is not implemented!\n");
> > +        return E_NOTIMPL;
> > +    }
> > +
> > +    if (event)
> > +    {
> > +        FIXME("Event parameter support is not implemented!\n");
> > +        return E_NOTIMPL;
> > +    }
> > +
> > +    if (flags & ~SSUPDATE_ASYNC)
> > +    {
> > +        FIXME("Unsupported flags: %x\n", flags);
> > +        return E_NOTIMPL;
> > +    }
> > +
> > +    EnterCriticalSection(&stream->cs);
> > +
> > +    if (stream->state == State_Stopped)
> > +    {
> > +        LeaveCriticalSection(&stream->cs);
> > +        return MS_E_NOTRUNNING;
> > +    }
> 
> Do you have tests for how Update() behaves while paused? If it's as
> simple as "identical to stopped or running", it'd be nice to add a quick
> test below.
> 

> > +    if (!stream->peer)
> > +    {
> > +        LeaveCriticalSection(&stream->cs);
> > +        return MS_S_ENDOFSTREAM;
> > +    }
> > +    if (MS_S_PENDING == sample->update_hr)
> > +    {
> > +        LeaveCriticalSection(&stream->cs);
> > +        return MS_E_BUSY;
> > +    }
> > +
> > +    sample->length = length;
> > +    sample->pointer = pointer;
> > +    sample->position = 0;
> > +    sample->update_hr = MS_S_PENDING;
> > +    ResetEvent(sample->update_event);
> > +    list_add_tail(&stream->update_queue, &sample->entry);
> > +
> > +    process_updates(stream);
> > +
> > +    hr = sample->update_hr;
> > +    if (hr != MS_S_PENDING || (flags & SSUPDATE_ASYNC))
> > +    {
> > +        LeaveCriticalSection(&stream->cs);
> > +        return hr;
> > +    }
> > +
> > +    LeaveCriticalSection(&stream->cs);
> > +
> > +    WaitForSingleObject(sample->update_event, INFINITE);
> > +
> > +    return sample->update_hr;
> > +}
> > +