Lua的简单单例和基于框架的单例类实现

Singleton = {}
function Singleton:new(o)
    o = o or {}
    setmetatable(o,self)
    self.__index = self
    return o
end
function Singleton:GetInstance()
    if self.instance == nil then
        self.instance = self:new()
    end
    return self.instance
end
s1 = Singleton:GetInstance()
s2 = Singleton:GetInstance()

基于自己的Lua框架的单例类：

--[[
-- 单例类
]]
---@class Singleton
local Singleton = BaseClass("Singleton")

local function __init(self)
    assert(rawget(self._class_type, "Instance") == nil, self._class_type.__cname .. " to create singleton twice!")
    rawset(self._class_type, "Instance", self)
end

local function __delete(self)
    rawset(self._class_type, "Instance", nil)
end

-- 只是用于启动模块
local function Startup(self)
end

-- 不要重写
local function GetInstance(self)
    if rawget(self, "Instance") == nil then
        rawset(self, "Instance", self.New())
    end
    assert(self.Instance ~= nil)
    return self.Instance
end

-- 不要重写
local function Delete(self)
    self.Instance = nil
end

Singleton.__init = __init
Singleton.__delete = __delete
Singleton.Startup = Startup
Singleton.GetInstance = GetInstance
Singleton.Delete= Delete

return Singleton