void SleepFor(SteadyClock::duration time) {
#ifdef _WIN32
static ULONG maxRes = 0;
static NTSTATUS(WINAPI * pNtSetTimerResolution)(
ULONG resolution, BOOLEAN set_resolution, ULONG * current_resolution);
static NTSTATUS(WINAPI * pNtDelayExecution)(BOOLEAN alertable,
const LARGE_INTEGER* timeout);
if (maxRes == 0) {
// Load ntdll.dll functions
std::string errorString;
DynamicLib ntdll = DynamicLib::Open("ntdll.dll", errorString);
if (!ntdll)
Sys::Error("Failed to load ntdll.dll: %s", errorString);
auto pNtQueryTimerResolution =
ntdll.LoadSym<NTSTATUS WINAPI(ULONG*, ULONG*, ULONG*) >(
"NtQueryTimerResolution", errorString);
if (!pNtQueryTimerResolution)
Sys::Error("Failed to load NtQueryTimerResolution from ntdll.dll: %s",
errorString);
pNtSetTimerResolution =
ntdll.LoadSym<NTSTATUS WINAPI(ULONG, BOOLEAN, ULONG*) >(
"NtSetTimerResolution", errorString);
if (!pNtSetTimerResolution)
Sys::Error("Failed to load NtSetTimerResolution from ntdll.dll: %s",
errorString);
pNtDelayExecution =
ntdll.LoadSym<NTSTATUS WINAPI(BOOLEAN, const LARGE_INTEGER*) >(
"NtDelayExecution", errorString);
if (!pNtDelayExecution)
Sys::Error("Failed to load NtDelayExecution from ntdll.dll: %s",
errorString);
// Determine the maximum available timer resolution
ULONG minRes, curRes;
if (pNtQueryTimerResolution(&minRes, &maxRes, &curRes) != 0)
maxRes = 10000; // Default to 1ms
}
// Increase the system timer resolution for the duration of the sleep
ULONG curRes;
pNtSetTimerResolution(maxRes, TRUE, &curRes);
// Convert to NT units of 100ns
typedef std::chrono::duration<int64_t, std::ratio<1, 10000000>> NTDuration;
auto ntTime = std::chrono::duration_cast<NTDuration>(time);
// Store the delay as a negative number to indicate a relative sleep
LARGE_INTEGER duration;
duration.QuadPart = -ntTime.count();
pNtDelayExecution(FALSE, &duration);
// Restore timer resolution after sleeping
pNtSetTimerResolution(maxRes, FALSE, &curRes);
#else
std::this_thread::sleep_for(time);
#endif
}
void sleep(uint32_t milliseconds)
{
// This should only be the case at the very beginning of execution.
if(pNtDelayExecution == NULL) {
Sleep(milliseconds);
return;
}
assert(pNtDelayExecution != NULL, "pNtDelayExecution is NULL!", );
LARGE_INTEGER li;
li.QuadPart = -10000 * (uint64_t) milliseconds;
pNtDelayExecution(FALSE, &li);
}
