repro.cpp

#include <Windows.h>
#include <stdio.h>
#include <chrono>

static const int COUNT = 50000u;

int main()
{
	DWORD charCount = MAX_PATH;
	wchar_t processName[MAX_PATH] = { '\0' };
	::QueryFullProcessImageNameW(::GetCurrentProcess(), 0u, processName, &charCount);
	printf("path: %ls\n", processName);

	{
		auto start = std::chrono::steady_clock::now();

		size_t checksum = 0u;
		for (int i = 0u; i < COUNT; ++i)
		{
			::WIN32_FILE_ATTRIBUTE_DATA attributes = {};
			const BOOL success = ::GetFileAttributesExW(processName, GetFileExInfoStandard, &attributes);
			if (success != FALSE)
			{
				checksum += attributes.nFileSizeLow;
			}
		}

		auto end = std::chrono::steady_clock::now();

		printf("SERIAL: Took %llu ms\n", std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count());
		printf("checksum: %zu\n", checksum);
	}

	return 0;
}