- Removed USE_GETTICKCOUNT code; it's never used now.
- Reduced the number of preprocessor checks for WinRT.
- Renamed timeSetPeriod() so it doesn't look like a Win32 API call.
An existing hint lets apps that don't need the timer resolution changed avoid
this, to save battery, etc, but this fixes several problems in timing, audio
callbacks not firing fast enough, etc.
Fixes Bugzilla #2944.
Visual C++ 2013 Update 4 re-introduced the Sleep() function to WinRT apps (for
code that targets Windows 8.1 and Windows Phone 8.1). This led to a build
error, as SDL was defining it's own Sleep() function (to make up for the lack
of a public Sleep() function). The fix makes sure that SDL's custom Sleep()
function is only used when Windows' Sleep() is not available.
Many thanks go out to Sergiu Marian Gaina for the fix!
Coriiander
In src\timer\windows\SDL_systimer.c there is an error with regards to timeBeginPeriod and timeEndPeriod. These functions typically get called when no high resolution timer is available, and GetTickCount is not used.
According to MSDN (link: http://msdn.microsoft.com/en-us/library/windows/desktop/dd757624(v=vs.85).aspx), for every call to timeBeginPeriod a subsequent call to timeEndPeriod is required. While SDL is currently doing this, it fails to call timeEndPeriod when cleaning up/shutting down SDL. Please note that these functions affect things on a system level. Failing to call timeEndPeriod, disables applications for using WINMM-timers after usage&shutdown of SDL, as effectively they the mechanism is now broken.
Solution:
Ensure this code gets called when shutting down the timer subsystem:
#ifndef USE_GETTICKCOUNT
if (!hires_timer_available)
{
timeSetPeriod(0);
}
#endif
It's a long-dead platform, and we don't have any way to build for, test, or
maintain it, so there's no sense in doing acrobatics to support it.
If you need Windows CE support, use SDL 1.2. If you need Windows Phone support,
send SDL 2.0 patches for the newer Windows Mobile platform.
The new timer model is formalized as using a separate thread to handle timer callbacks. This was the case on almost every platform before, but it's now a requirement, and simplifies the implementation and makes it perform consistently across platforms.
Goals:
* Minimize timer thread blocking
* Dispatch timers as accurately as possible
* SDL_AddTimer() and SDL_RemoveTimer() are completely threadsafe
* SDL_RemoveTimer() doesn't crash with a timer that's expired or removed
