[PATCH 1/4] winmm: Use microsecond unit in MIDI stream position variable to simplify the code.

[Akihiro Sagawa]

Andrew, thanks for reviewing.

Since 32-bit variable overflows after approximately 70 minutes,
we use 64-bit variable for this purpose. `remainder' member is removed.

Signed-off-by: Akihiro Sagawa 
---
 dlls/winmm/winmm.c | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

[Andrew Eikum]

Signed-off-by: Andrew Eikum

On Wed, Jul 11, 2018 at 10:33:19PM +0900, Akihiro Sagawa wrote:
> Andrew, thanks for reviewing.
>
> Since 32-bit variable overflows after approximately 70 minutes,
> we use 64-bit variable for this purpose. `remainder' member is removed.
> Signed-off-by: Akihiro Sagawa
>
> dlls/winmm/winmm.c | 20 +++++++-------------
>  1 file changed, 7 insertions(+), 13 deletions(-)
> diff --git a/dlls/winmm/winmm.c b/dlls/winmm/winmm.c
> index 0328721..4b8d4de 100644
> --- a/dlls/winmm/winmm.c
> +++ b/dlls/winmm/winmm.c
> @@ -915,13 +915,12 @@ typedef struct WINE_MIDIStream {
>      CRITICAL_SECTION		lock;
>      DWORD			dwTempo;
>      DWORD			dwTimeDiv;
> - DWORD			dwPositionMS;
> - ULONGLONG			position_usec;
> DWORD			dwPulses;
> DWORD			dwStartTicks;
> DWORD			dwElapsedMS;
> WORD			wFlags;
> WORD			status;
> - WORD			remainder;
> HANDLE			hEvent;
> LPMIDIHDR			lpMidiHdr;
>
> } WINE_MIDIStream;
> @@ -1008,8 +1007,7 @@ static	BOOL	MMSYSTEM_MidiStream_MessageHandler(WINE_MIDIStream* lpMidiStrm, LPWI
>              lpMidiStrm->status = MSM_STATUS_STOPPED;
>              lpMidiStrm->dwPulses = 0;
>              lpMidiStrm->dwElapsedMS = 0;
> -
>        lpMidiStrm->dwPositionMS = 0;
> -
>        lpMidiStrm->remainder = 0;
> -
>        lpMidiStrm->position_usec = 0;
>        LeaveCriticalSection(&lpMidiStrm->lock);
>        /* this is not quite what MS doc says... */
>        midiOutReset(lpMidiStrm->hDevice);
>
> @@ -1181,15 +1179,12 @@ start_header:
>
> /* do we have to wait ? */
>    if (me->dwDeltaTime) {
> -
>    DWORD delta;
>  EnterCriticalSection(&lpMidiStrm->lock);
> -
>    delta = lpMidiStrm->remainder + MMSYSTEM_MidiStream_Convert(lpMidiStrm, me->dwDeltaTime);
> -
>    lpMidiStrm->dwPositionMS += delta / 1000;
> -
>    lpMidiStrm->remainder = delta % 1000;
> -
>    lpMidiStrm->position_usec += MMSYSTEM_MidiStream_Convert(lpMidiStrm, me->dwDeltaTime);
>  lpMidiStrm->dwPulses += me->dwDeltaTime;
>  LeaveCriticalSection(&lpMidiStrm->lock);
>
> -
>    dwToGo = lpMidiStrm->dwStartTicks + lpMidiStrm->dwPositionMS;
> -
>    dwToGo = lpMidiStrm->dwStartTicks + lpMidiStrm->position_usec / 1000;
>
>  TRACE("%u/%u/%u\n", dwToGo, GetTickCount(), me->dwDeltaTime);
>  while (dwToGo - (dwCurrTC = GetTickCount()) <= MAXLONG) {
>
> @@ -1204,7 +1199,7 @@ start_header:
>    		}
>    	    }
>    	    /* reset dwToGo because dwStartTicks might be updated */
> -
>     dwToGo = lpMidiStrm->dwStartTicks + lpMidiStrm->dwPositionMS;
> -
>     dwToGo = lpMidiStrm->dwStartTicks + lpMidiStrm->position_usec / 1000;
> } else {
>    /* timeout, so me->dwDeltaTime is elapsed, can break the while loop */
>    break;
>
> @@ -1334,10 +1329,9 @@ MMRESULT WINAPI midiStreamOpen(HMIDISTRM* lphMidiStrm, LPUINT lpuDeviceID,
>      if (!lpMidiStrm)
>    return MMSYSERR_NOMEM;
> - lpMidiStrm->dwTempo = 500000;  /* micro seconds per quarter note, i.e. 120 BPM */
> - lpMidiStrm->dwTempo = 500000;  /* microseconds per quarter note, i.e. 120 BPM */
> lpMidiStrm->dwTimeDiv = 24;    /* ticks per quarter note */
> - lpMidiStrm->dwPositionMS = 0;
> - lpMidiStrm->remainder = 0;
> - lpMidiStrm->position_usec = 0;
> lpMidiStrm->status = MSM_STATUS_PAUSED;
> lpMidiStrm->dwElapsedMS = 0;
>