golang使用arena进行内存控制为什么会出现无效访问？

Question

在golang中，尝试使用arena进行手动内存释放

代码：

package main

import (
    "arena"
    "encoding/json"
    "fmt"
    "runtime"
    "strconv"
    "strings"

    "github.com/glebarez/sqlite"
    "github.com/gofiber/fiber/v2"
    "gorm.io/gorm"
)

type RoadDeviceVehicle struct {
    RoadPoint string
}

type TT struct {
    PointX    string `json:"pointX"`
    PointY    string `json:"pointY"`
    Timestamp string `json:"timestamp"`
}

type TTT struct {
    PointX    float32
    PointY    float32
    Timestamp int64
}

func main() {
    db, err := gorm.Open(sqlite.Open("road_device_vehicle.db"), &gorm.Config{})
    if err != nil {
        fmt.Println(err)
        panic("failed to connect database")
    }

    tmem := arena.NewArena()
    roadVehicles := arena.MakeSlice[RoadDeviceVehicle](tmem, 0, 1500000)
    db.Table("road_device_vehicle").Select("road_point").Find(&roadVehicles)

    tts := arena.MakeSlice[[]TT](tmem, len(roadVehicles), len(roadVehicles))
    for idx := range roadVehicles {
        tts[idx] = make([]TT, 0, 20)
        s := strings.Replace(roadVehicles[idx].RoadPoint, "\\", "", -1)
        json.Unmarshal([]byte(s), &tts[idx])
    }

    tttsmem := arena.NewArena()
    ttts := arena.MakeSlice[[]TTT](tttsmem, len(tts), len(tts))
    for idx := range tts {
        ttts[idx] = arena.MakeSlice[TTT](tttsmem, len(tts[idx]), len(tts[idx]))
        for idx2 := range tts[idx] {
            t, err := strconv.ParseFloat(tts[idx][idx2].PointX, 32)
            if err != nil {
                fmt.Println(err)
                return
            }
            ttts[idx][idx2].PointX = float32(t)

            t, err = strconv.ParseFloat(tts[idx][idx2].PointY, 32)
            if err != nil {
                fmt.Println(err)
                return
            }
            ttts[idx][idx2].PointY = float32(t)

            ttts[idx][idx2].Timestamp, err = strconv.ParseInt(tts[idx][idx2].Timestamp, 10, 64)
            if err != nil {
                fmt.Println(err)
                return
            }
        }
    }

    tmem.Free()
    runtime.GC()

    app := fiber.New()

    app.Get("/db", func(c *fiber.Ctx) error {
        fmt.Println(ttts[0][0])
        return c.SendString("Hello, World!")
    })

    app.Listen(":3000")
}

在以上代码中，RoadPoint字符串类似于如下:

[{\"pointX\":\"212.13\",\"pointY\":\"61724922.54\",\"timestamp\":\"1704970150739\"},{\"pointX\":\"228.30\",\"pointY\":\"61728661.51\",\"timestamp\":\"1704970152777\"},{\"pointX\":\"188.10\",\"pointY\":\"61732802.98\",\"timestamp\":\"1704970154739\"},{\"pointX\":\"188.04\",\"pointY\":\"61737013.77\",\"timestamp\":\"1704970156738\"},{\"pointX\":\"151.57\",\"pointY\":\"61742215.45\",\"timestamp\":\"1704970158777\"}]

使用tmem.Free()之后，读取ttts字段会报错，信息如下:

accessed data from freed user arena 0x40c0007eff70
fatal error: fault
[signal 0xc0000005 code=0x0 addr=0x40c0007eff70 pc=0xfdf390]

请问为什么会出现这种情况，ttts不是使用tttsmem分配的吗，为什么我free了tmem后会导致ttts无法读取

使用普通的make，则可以依靠垃圾回收正确获取结果