An example FrameHeap in Go

frameheap.go

package main

import "fmt"
import "unsafe"

func NewFrameHeap(size int) *FrameHeap {
	buffer := make([]uint8, size)
	location := uintptr(unsafe.Pointer(&buffer[0]))
	return &FrameHeap{
		buffer: buffer, // Store it to prevent GC?
		start: location,
		current: location,
	}
}

type FrameHeap struct {
	buffer []uint8
	start uintptr
	current uintptr
}

func (h *FrameHeap) Allocate(count uintptr) unsafe.Pointer {
	result := h.current
	h.current += count
	return unsafe.Pointer(&result)
}

func (h *FrameHeap) Reset() {
	for i := range h.buffer {
		h.buffer[i] = 0
	}
	h.current = h.start
}

type Vector struct {
	X, Y, Z float32
}

type Counter struct {
	Value int
}

func main() {
	heap := NewFrameHeap(64)
	vec := *(**Vector)(heap.Allocate(unsafe.Sizeof(Vector{})))
	vec.X = 11.0
	vec.Y = 22.0
	vec.Z = 33.0
	
	cnt := *(**Counter)(heap.Allocate(unsafe.Sizeof(Counter{})))
	cnt.Value = 951
	
	fmt.Printf("Vector: %#v\n", vec)
	fmt.Printf("Counter: %#v\n", cnt)
	fmt.Printf("Heap: %#v\n", heap.buffer)

	fmt.Println()	
	fmt.Println("Clearing heap...")
	heap.Reset()
	fmt.Println()
	
	fmt.Printf("Vector: %#v\n", vec)
	fmt.Printf("Counter: %#v\n", cnt)
	fmt.Printf("Heap: %#v\n", heap.buffer)
}