winmm: Default to 1ms resolution like we used to.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=49564
Signed-off-by: Arkadiusz Hiler <ahiler@codeweavers.com>
Signed-off-by: Andrew Eikum <aeikum@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
This commit is contained in:
Arkadiusz Hiler 2020-08-25 10:54:01 +03:00 committed by Alexandre Julliard
parent 781d530e9c
commit e01ef81379
1 changed files with 25 additions and 6 deletions

View File

@ -74,17 +74,30 @@ static inline void link_timer( WINE_TIMERENTRY *timer )
/*
* Some observations on the behavior of winmm on Windows.
* First, the call to timeBeginPeriod(xx) can never be used
* to raise the timer resolution, only lower it.
*
* First, the call to timeBeginPeriod(xx) can never be used to
* lower the timer resolution (i.e. increase the update
* interval), only to increase the timer resolution (i.e. lower
* the update interval).
*
* Second, a brief survey of a variety of Win 2k and Win X
* machines showed that a 'standard' (aka default) timer
* resolution was 1 ms (Win9x is documented as being 1). However, one
* machine had a standard timer resolution of 10 ms.
*
* Further, if we set our default resolution to 1,
* the implementation of timeGetTime becomes GetTickCount(),
* and we can optimize the code to reduce overhead.
* Further, timeBeginPeriod(xx) also affects the resolution of
* wait calls such as NtDelayExecution() and
* NtWaitForMultipleObjects() which by default round up their
* timeout to the nearest multiple of 15.625ms across all Windows
* versions. In Wine all of those currently work with sub-1ms
* accuracy.
*
* Effective time resolution is a global value that is the max
* of the resolutions (i.e. min of update intervals) requested by
* all the processes. A lot of programs seem to do
* timeBeginPeriod(1) forcing it onto everyone else.
*
* Defaulting to 1ms accuracy in winmm should be safe.
*
* Additionally, a survey of Event behaviors shows that
* if we request a Periodic event every 50 ms, then Windows
@ -97,6 +110,7 @@ static inline void link_timer( WINE_TIMERENTRY *timer )
* no delays.
*
* Jeremy White, October 2004
* Arkadiusz Hiler, August 2020
*/
#define MMSYSTIME_MININTERVAL (1)
#define MMSYSTIME_MAXINTERVAL (65535)
@ -255,7 +269,12 @@ MMRESULT WINAPI timeGetSystemTime(LPMMTIME lpTime, UINT wSize)
*/
DWORD WINAPI timeGetTime(void)
{
return GetTickCount();
LARGE_INTEGER now, freq;
QueryPerformanceCounter(&now);
QueryPerformanceFrequency(&freq);
return (now.QuadPart * 1000) / freq.QuadPart;
}
/**************************************************************************