monitor - prepare execution profile
monitor(lowpc, highpc, buffer, bufsize, nfunc)
int (*lowpc)( ), (*highpc)( );
short buffer[ ];
An executable program created by `cc -p' automatically includes calls for monitor with
default parameters; monitor needn't be called explicitly except to gain fine control over
Monitor is an interface to profil(2). Lowpc and highpc are the addresses of two func-
tions; buffer is the address of a (user supplied) array of bufsize short integers. Moni-
tor arranges to record a histogram of periodically sampled values of the program counter,
and of counts of calls of certain functions, in the buffer. The lowest address sampled is
that of lowpc and the highest is just below highpc. At most nfunc call counts can be
kept; only calls of functions compiled with the profiling option -p of cc(1) are recorded.
For the results to be significant, especially where there are small, heavily used rou-
tines, it is suggested that the buffer be no more than a few times smaller than the range
of locations sampled.
To profile the entire program, it is sufficient to use
monitor((int)2, etext, buf, bufsize, nfunc);
Etext lies just above all the program text, see end(3).
To stop execution monitoring and write the results on the file mon.out, use
then prof(1) can be used to examine the results.
prof(1), profil(2), cc(1)