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MONCONTROL(3) FreeBSD Library Functions Manual MONCONTROL(3)
NAME
moncontrol, monstartup - control execution profile
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <sys/types.h>
#include <sys/gmon.h>
void
moncontrol(int mode);
void
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 program
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 examine
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
resume the collection of histogram ticks and call counts use
moncontrol(1). This feature allows the cost of particular operations to
be measured. 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 collect profiling
statistics by calling monstartup() with the range of addresses 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().
ENVIRONMENT
The following environment variables affect the execution of moncontrol:
PROFIL_USE_PID If set, the pid of the process is inserted into the
filename.
FILES
progname.gmon execution data file
SEE ALSO
cc(1), gprof(1), profil(2), clocks(7)
FreeBSD 14.0-RELEASE-p11 June 14, 2004 FreeBSD 14.0-RELEASE-p11