net-snmp库snmp API解读分析.doc

导读
net-snmp API分为两种,一种叫传统API(Traditional API),一种叫单个API(Single API)。早期的neet-snmp没有考虑到多线程的问题,所有的会话共享同一个资源,这些就是传统API,后来支持多线程的就叫做单个API。,这里贴出一部分关键内容。
The functions in the following table are functionally equivalent,
with the exception of these behaviors:
- The Traditional API manages many sessions
- The Traditional API passes a struct snmp_session pointer,
       and touches the Sessions list
- The Single API manages only one session
- The Single API passes an opaque pointer, and does not use Sessions list
 
  Traditional        Single                    Comment
  ===========        ==============            =======
  snmp_sess_init     snmp_sess_init            Call before either open
  snmp_open          snmp_sess_open            Single not on Sessions list
                     snmp_sess_session         Exposes snmp_session pointer
  snmp_send          snmp_sess_send            Send one APDU
  snmp_async_send    snmp_sess_async_send      Send one APDU with callback
  snmp_select_info   snmp_sess_select_info     Which session(s) have input
  snmp_read          snmp_sess_read            Read APDUs
  snmp_timeout       snmp_sess_timeout         Check for timeout
  snmp_close         snmp_sess_close           Single not on Sessions list
 snmp_synch_response snmp_sess_synch_response  Send/receive one APDU
  snmp_error         snmp