// TODO(jayconrod): set a reasonable maximum size per platform.
	return int(unsafe.Sizeof(sharedMemHeader{})) + valueSize
}

// sharedMemTempFile creates a new temporary file of the given size, then maps
// it into memory. The file will be removed when the Close method is called.
func sharedMemTempFile(size int) (m *sharedMem, err error) {
	// Create a temporary file.
	f, err := os.CreateTemp("", "fuzz-*")
	if err != nil {
		return nil, err

	ws := &workerServer{
		fuzzFn:     func(_ CorpusEntry) (time.Duration, error) { return time.Second, nil },
		workerComm: workerComm{memMu: make(chan *sharedMem, 1)},
	}

	mem, err := sharedMemTempFile(workerSharedMemSize)
	if err != nil {
		b.Fatalf("failed to create temporary shared memory file: %s", err)
	}
	defer func() {
		if err := mem.Close(); err != nil {
			b.Error(err)
		}
	}()

		return nil, err
	}

	return &sharedMem{f: f, region: region, removeOnClose: removeOnClose}, nil
}

// Close unmaps the shared memory and closes the temporary file. If this
// sharedMem was created with sharedMemTempFile, Close also removes the file.
func (m *sharedMem) Close() error {
	// Attempt all operations, even if we get an error for an earlier operation.
	// os.File.Close may fail due to I/O errors, but we still want to delete

		removeOnClose: removeOnClose,
		sys:           sharedMemSys{mapObj: mapObj},
	}, nil
}

// Close unmaps the shared memory and closes the temporary file. If this
// sharedMem was created with sharedMemTempFile, Close also removes the file.
func (m *sharedMem) Close() error {
	// Attempt all operations, even if we get an error for an earlier operation.
	// os.File.Close may fail due to I/O errors, but we still want to delete

	termC       chan struct{} // closed by wait when worker process terminates
}

func newWorker(c *coordinator, dir, binPath string, args, env []string) (*worker, error) {
	mem, err := sharedMemTempFile(workerSharedMemSize)
	if err != nil {
		return nil, err
	}
	memMu := make(chan *sharedMem, 1)
	memMu <- mem
	return &worker{
		dir:         dir,
		binPath:     binPath,
		args:        args,