moncontrol(3)

NAME

moncontrol, monstartup - control execution profile

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <sys/types.h>
#include <sys/gmon.h>
int
moncontrol(int mode);
int
monstartup(u_long *lowpc, u_long *highpc);

DESCRIPTION

An executable program compiled using the -pg option to cc(1)

automatically includes calls to collect statistics for the gprof(1)

call-graph
execution profiler. In typical operation, profiling begins

at program
startup and ends when the program calls exit. When the pro

gram exits,
the profiling data are written to the file progname.gmon,

where progname
is the name of the program, then gprof(1) can be used to ex

amine the
results.

The moncontrol() function selectively controls profiling

within a program. When the program starts, profiling begins. To stop

the collection
of histogram ticks and call counts use moncontrol(0); to re

sume the collection of histogram ticks and call counts use

moncontrol(1). This feature allows the cost of particular operations to be mea

sured. Note that
an output file will be produced on program exit regardless

of the state
of moncontrol().

Programs that are not loaded with -pg may selectively col

lect profiling
statistics by calling monstartup() with the range of ad

dresses to be profiled. The lowpc and highpc arguments specify the address

range that is
to be sampled; the lowest address sampled is that of lowpc

and the highest is just below highpc. Only functions in that range that

have been
compiled with the -pg option to cc(1) will appear in the

call graph part
of the output; however, all functions in that address range

will have
their execution time measured. Profiling begins on return

from
monstartup().

FILES

progname.gmon execution data file

SEE ALSO

cc(1), gprof(1), profil(2), clocks(7)

BSD June 14, 2004

BSD