1 files changed, 66 insertions, 0 deletions

diff --git a/src/OSSupport/SleepResolutionBooster.h b/src/OSSupport/SleepResolutionBooster.h
new file mode 100644
index 000000000..f090f6963
--- /dev/null
+++ b/src/OSSupport/SleepResolutionBooster.h
@@ -0,0 +1,66 @@
+
+// SleepResolutionBooster.h
+
+// Increases the accuracy of Sleep on Windows (GH #5140).
+
+// This file MUST NOT be included from anywhere other than main.cpp.
+
+
+
+
+
+#ifdef _WIN32
+
+#include <timeapi.h>
+
+
+
+
+
+static TIMECAPS g_Resolution;
+
+
+
+
+
+namespace SleepResolutionBooster
+{
+	static void Register()
+	{
+		// Default sleep resolution on Windows isn't accurate enough (GH #5140) so try to boost it:
+		if (
+			(timeGetDevCaps(&g_Resolution, sizeof(g_Resolution)) == MMSYSERR_NOERROR) &&
+			(timeBeginPeriod(g_Resolution.wPeriodMin) == MMSYSERR_NOERROR)
+		)
+		{
+			return;
+		}
+
+		// Max < Min sentinel for failure, to prevent bogus timeEndPeriod calls:
+		g_Resolution.wPeriodMax = 0;
+		g_Resolution.wPeriodMin = 1;
+	}
+
+	static void Unregister()
+	{
+		if (g_Resolution.wPeriodMax >= g_Resolution.wPeriodMin)
+		{
+			timeEndPeriod(g_Resolution.wPeriodMin);
+		}
+	}
+};
+
+#else
+
+namespace SleepResolutionBooster
+{
+	static void Register()
+	{
+	}
+
+	static void Unregister()
+	{
+	}
+};
+
+#endif