in src/watchdog.cc [30:40]
bool w_processIsRunning(long pid)
{
#if defined(WIN32)
HANDLE process = OpenProcess(SYNCHRONIZE, FALSE, pid);
DWORD ret = WaitForSingleObject(process, 0);
CloseHandle(process);
return (ret == WAIT_TIMEOUT);
#else
return (kill(pid, 0) == 0);
#endif
}