// are implemented inside of race runtime.
	kernel32 := syscall.NewLazyDLL("kernel32.dll")
	VirtualAlloc := kernel32.NewProc("VirtualAlloc")
	VirtualFree := kernel32.NewProc("VirtualFree")
	const (
		MEM_COMMIT     = 0x00001000
		MEM_RESERVE    = 0x00002000
		MEM_RELEASE    = 0x8000
		PAGE_READWRITE = 0x04
	)

	if r != 0 {
		return
	}

	// Decommit failed. Usual reason is that we've merged memory from two different
	// VirtualAlloc calls, and Windows will only let each VirtualFree handle pages from
	// a single VirtualAlloc. It is okay to specify a subset of the pages from a single alloc,
	// just not pages from multiple allocs. This is a rare case, arising only when we're