NAME
monitor - prepare execution profile
SYNOPSIS
monitor(lowpc, highpc, buffer, bufsize)
int lowpc( ), highpc( ), buffer[ ], bufsize;
DESCRIPTION
Monitor is an interface to the system's profile entry (II).
Lowpc and highpc are the names of two functions; buffer is
the address of a (user supplied) array of bufsize integers.
Monitor arranges for the system to sample the user's program
counter periodically and record the execution histogram in
the buffer. The lowest address sampled is that of lowpc and
the highest is just below highpc. For the results to be
significant, especially where there are small, heavily used
routines, 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
extern etext;
...
monitor(2, &etext, buf, bufsize);
Etext is a loader-defined symbol which lies just above all
the program text.
To stop execution monitoring and write the results on the
file mon.out, use
monitor(0);
Then, when the program exits, prof (I) can be used to exam-
ine the results.
It is seldom necessary to call this routine directly; the -p
option of cc is simpler if one is satisfied with its default
profile range and resolution.
FILES
mon.out
SEE ALSO
prof (I), profil (II), cc (I)
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