【米尔-MYD-LR3568-GK开发板--试用评测】G.阿里云客户端分析
阿里云客户端，笔者使用过一次，上次用作网关，这次用作客户端阿里云客户端源码分析：
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/200918xdjoijdm8xjikxm7.png)
`175 行先实现 struct aiot_sysdep_portfile_t 变量 g_aiot_sysdep_portfile 中的接口`!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201008o61lkl9u55y66866.png)
详细接口实现如下：就是阿里云客户端调用的平台级接口，用 linux 平台接口实现阿里云客户端接口
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201020p4omdbdrm93lpb24.png)
`把自己移植实现的接口保存到变量g_origin_portfile中，网络接口重新定后的变量g_aiot_portfile 保存为 g_sysdep_portfile`
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201050d2zaxyp4agp9pbi7.png)
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201052ytgn12yznt9pm32t.png)
分析网络接口重定向
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201055w37wn699wo3wjo76.png)
还是对 g_origin_portfile 的封装
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201125e3eqhsqrv0w3y6z7.png)
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201128d86hizwzvwl6wsgk.png)
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201132ahhhghym9n23h2tg.png)
重定向好处是，添加平台无关，客户端又需要的功能
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201155xwp7dgw7ja77wkdo.png)
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201157u6mbjwdbzsz0608n.png)
继续分析核心代码：
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201209mf4iu9edxkco5990.png)
`aiot_mqtt_init 检查移植的接口，申请 mqtt_handle 内存，初始化mqtt_handle`
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201252gp5chdppapmbphca.png)
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201256qwdvd9xfdvfezzxm.png)
继续初始化mqtt_handle
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201307gc0vg0zkisnm1d30.png)
初始化了两个函数 recv_handler 和 event_handler
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201327n0oty25nen5***f.png)
recv_handler接收到订阅的消息，处理函数。阿里云向开发板下发的消息，在这里处理和实现
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201343q0ceavaauzc3fafs.png)
event_handler是阿里云客户端自身事件的处理函数，和业务无关
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201356bwyo33zqjp4ha0n3.png)
继续分析核心代码：
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201404whieykw30j3s31cc.png)
连接服务器：
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201412z10040nwz45eu0j2.png)
事件通知：
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201424vr4fsus8yamjge81.png)
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201426ckqlalprhhk4rhuq.png)
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201431esdda5umgr5vq5ds.png)
继续分析核心代码：创建两个进程，进入死循环
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201439xi6etupqz6b6p6bx.png)
demo_mqtt_process_thread 进程是个系循环，每秒处理一次数据
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201453dr9o0ayf570ot3az.png)
处理心跳，qos，事件处理
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201501xqhbczqyfcu1zc8f.png)
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201504cmu8huvekmaeumuu.png)
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201507w7imbqkqbhzgqmeb.png)
接受进程aiot_mqtt_recv 接收到消息，解析消息
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201521qpstr3f3khmk3rai.png)
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201525pzf2etfrvo222r32.png)
根据不同的消息类型，调用不同函数处理
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201532c84fb2yii344pbji.png)
`_core_mqtt_subunsuback_handler 保存数据，调 mqtt_handle->recv_handler 处理，mqtt_handle->recv_handler 上面分析过，处理阿里云下发的指令`
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201554hs5r0bsgcggjkkch.png)
死循环后面代码不会执行，不用继续分析了
以上是阿里云客户端整体框架，层次很清晰，其实就是 mqtt 的物联网客户端。
有一点不太彻底的是 pthread\_create 函数，还是和平台相关的接口，没有完全剥离，比如想移植到 freertos 平台，是要用 prvCreateTask 来实现pthread\_create的功能
在分析两个使用到的函数：1，sub 订阅消息函数
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201615pxhcm65xaf2m4m47.png)
验证消息有效，插入列表
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201623oj805dzbbe7jyd1j.png)
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201627sp1ndvnmdl4l4w24.png)
插入列表完事，并没有真正去接受消息。往上翻也有这个列表mqtt_handle->sub_list，独立进程遍历这个列表有消息调用。完美闭环。
2，pub 发布消息函数
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201706nf7nahr41efpannw.png)
调用 _core_mqtt_write 发布消息
!(//m.qjumbo.com/forum/data/attachment/forum/202411/17/201720t779wu842aga3kqf.png)
要实现业务，调用 pub 发布上行数据，调用 sub 订阅后，往 recv_handler 添加下行命令的处理函数。即可实现阿里云到开发板双向通信。
以上框架梳理清晰，稍后实现自己业务时思路和逻辑就清晰了。
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