MONITOR(S) UNIX System V MONITOR(S)
Name
monitor - prepare execution profile
Syntax
#include <mon.h>
void monitor (lowpc, highpc, buffer, bufsize, nfunc)
int (*lowpc)( ), (*highpc)( );
WORD *buffer;
int bufsize, nfunc;
Description
An executable program created by cc -p automatically
includes calls for monitor with default parameters; monitor
need not be called explicitly except to gain fine control
over profiling.
The monitor function is an interface to profil(S). lowpc
and highpc are the addresses of two functions; buffer is the
address of a user-supplied array of bufsize WORDs (defined
in the <mon.h> header file). monitor records a histogram of
two items: periodically sampled values of the program
counter and counts of calls to certain functions. This
histogram is recorded in the buffer. The lowest address
sampled is that of lowpc and the highest is just below
highpc. lowpc may not equal 0 for this use of monitor. At
most nfunc, call counts can be kept; only calls of functions
compiled with the profiling option -p of cc(CP) are
recorded.
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 ((int (*)())2, &etext, buf, bufsize, nfunc);
etext lies just above all the program text; see end(S).
To stop execution monitoring and write the results, use
monitor ((int (*)())0, 0, 0, 0, 0);
The prof(CP) command can then be used to examine the
results.
The name of the file written by monitor is controlled by the
environment variable PROFDIR. If PROFDIR does not exist,
``mon.out'' is created in the current directory. If PROFDIR
exists but has no value, monitor does not do any profiling
and creates no output file. Otherwise, the value of PROFDIR
is used as the name of the directory in which to create the
output file. If PROFDIR is dirname, then the file written
is ``dirname/pid.mon.out'' where pid is the program's
process ID. (When monitor is called automatically by
compiling via cc -p, the file created is
``dirname/pid.progname'' where progname is the name of the
program.)
Files
mon.out
See Also
cc(CP), prof(CP), profil(S), end(S)
Notes
The ``dirname/pid.mon.out'' form does not work; the
``dirname/pid.progname'' form (automatically called via cc
-p) does work.
Standards Conformance
monitor is conformant with:
AT&T SVID Issue 2, Select Code 307-127;
and The X/Open Portability Guide II of January 1987.
(printed 6/20/89)