UDT Reference: CUDT Methods

trace

The trace method prints the internal protocol parameters and performance trace to the screen or a file.

void trace(
   const int& interval = 1000000,

   const char* tracefile = NULL
);

Parameters

interval
[in] The trace sample interval, in microseconds.
tracefile
[in] the name of the trace file, default is NULL, which means output will be print to screen.

Return Values

NONE.

Exceptions

NONE.

Description

The trace method is to help performance testing and trouble shooting. This method is not enabled unless the "-DTRACE" option is set at compile time.

The trace format is as follows:

Sending Speed Receiving Speed Flow Window Size Inter-Packet Time RTT Sent ACK Received ACK Sent NAK Receved NAK Loss Rate
Mbps Mbps   us ms         %

The trace method simply enables the trace output and will returns immediately. If this method is called more than once in one UDT session, only the first call works and all the followings are omitted. The sample interval should be able to be divided by 0.01 seconds, or 10000 microseconds, otherwise it is rounded to the smallest value that can be divided by 0.01 but is greater than the input value. Meanwhile, any value that is less than 0.1 seconds, or 100000 microseconds will not produce any trace.