static int windows_clock_gettime(int clk_id, struct timespec *tp)
{
struct timer_request request;
#if !defined(_MSC_VER) || (_MSC_VER < 1900)
FILETIME filetime;
ULARGE_INTEGER rtime;
#endif
DWORD r;
switch (clk_id) {
case USBI_CLOCK_MONOTONIC:
if (timer_thread) {
request.tp = tp;
request.event = CreateEvent(NULL, FALSE, FALSE, NULL);
if (request.event == NULL)
return LIBUSB_ERROR_NO_MEM;
if (!pPostThreadMessageA(timer_thread_id, WM_TIMER_REQUEST, 0, (LPARAM)&request)) {
usbi_err(NULL, "PostThreadMessage failed for timer thread: %s", windows_error_str(0));
CloseHandle(request.event);
return LIBUSB_ERROR_OTHER;
}
do {
r = WaitForSingleObject(request.event, TIMER_REQUEST_RETRY_MS);
if (r == WAIT_TIMEOUT)
usbi_dbg("could not obtain a timer value within reasonable timeframe - too much load?");
else if (r == WAIT_FAILED)
usbi_err(NULL, "WaitForSingleObject failed: %s", windows_error_str(0));
} while (r == WAIT_TIMEOUT);
CloseHandle(request.event);
if (r == WAIT_OBJECT_0)
return LIBUSB_SUCCESS;
else
return LIBUSB_ERROR_OTHER;
}
// Fall through and return real-time if monotonic was not detected @ timer init
case USBI_CLOCK_REALTIME:
#if defined(_MSC_VER) && (_MSC_VER >= 1900)
timespec_get(tp, TIME_UTC);
#else
// We follow http://msdn.microsoft.com/en-us/library/ms724928%28VS.85%29.aspx
// with a predef epoch time to have an epoch that starts at 1970.01.01 00:00
// Note however that our resolution is bounded by the Windows system time
// functions and is at best of the order of 1 ms (or, usually, worse)
GetSystemTimeAsFileTime(&filetime);
rtime.LowPart = filetime.dwLowDateTime;
rtime.HighPart = filetime.dwHighDateTime;
rtime.QuadPart -= EPOCH_TIME;
tp->tv_sec = (long)(rtime.QuadPart / 10000000);
tp->tv_nsec = (long)((rtime.QuadPart % 10000000) * 100);
#endif
return LIBUSB_SUCCESS;
default:
return LIBUSB_ERROR_INVALID_PARAM;
}
}
void windows_destroy_clock(void)
{
if (timer_thread) {
// actually the signal to quit the thread.
if (!pPostThreadMessageA(timer_thread_id, WM_TIMER_EXIT, 0, 0)
|| (WaitForSingleObject(timer_thread, INFINITE) != WAIT_OBJECT_0)) {
usbi_dbg("could not wait for timer thread to quit");
TerminateThread(timer_thread, 1);
// shouldn't happen, but we're destroying
// all objects it might have held anyway.
}
CloseHandle(timer_thread);
timer_thread = NULL;
timer_thread_id = 0;
}
}
