What is the purpose of the change

Support user data in async callback

Brief changelog

typedef void (COnSendSuccessCallback)(CSendResult result, CMessage msg, void* userData);
typedef void (COnSendExceptionCallback)(CMQException e, CMessage msg, void* userData);
ROCKETMQCLIENT_API int SendAsync(CProducer* producer,
CMessage* msg,
COnSendSuccessCallback cSendSuccessCallback,
COnSendExceptionCallback cSendExceptionCallback,
void* userData);

Verifying this change

see the code

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