Introduction - If you have any usage issues, please Google them yourself
A mobile communication system, the requirements call for each user is assigned a call ID (callid), one of CallID plastic for unsigned values. There is a class callid, callid pool implementation functions. Initialization give the largest logo, call the beginning of the requirements can apply for a callid, can call the end of the release, you can print is being used separately or callid list, set for with calid can determine the validity of (0 ~ max callid), whether at busy.