Example--Timing Functions

In Example 1-4, probe points are placed at the entry and exit of a function to see how much time is spent in the function. The probe at the function entry also logs the arguments to the function.

When prex encounters a probe point at run time that is enabled for tracing, it writes a record to the trace file. Each probe point logs the time when it was encountered and also references a tag record containing information like the file name, line number, name, keys, and detail of the probe point. These tag records are written only once, and are never overwritten in the trace file.

The first probe point, work_args, also logs the value of the two arguments of the probe point (state and message).

Example 1-4 Probe Points at Entry and Exit of Function

#include <tnf/probe.h>

int
work(int state, char *message)
{
    TNF_PROBE_2(work_start, "work_module work"
               "sunw%debug in function work",
               tnf_long, int_input, state,
               tnf_string, string_input, message);
   ...
    TNF_PROBE_0(work_end, "work_module work", "");
}