The perfmon method retrieves the internal protocol parameters and performance trace.
If success, 0 is returned and trace information is written into trace; otherwise, UDT::ERROR is returned and specific error information can be retrieved by getlasterror.
Error Name | Error Code | Comment |
ECONNLOST | 2001 | connection is broken. |
EINVSOCK | 5004 | u is an invalid socket. |
EUNBOUNDSOCK | 5005 | u is not connected. |
The perfmon method reads the performance data since the last time perfmon is executed, or since the connection is started. The result in written into a TRACEINFO structure.
There are three kinds of performance information that can be read by applications: the total counts since the connection is started, the periodical counts since last time the counts are cleared, and instant parameter values.