NAME

moncontrol — control execution profile

SYNOPSIS

#include <sys/gmon.h>

void
moncontrol(int mode);

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. Profiling begins at program startup and ends when the program calls exit. When the program exits, the profiling data are written to the file gmon.progname.pid.out, then gprof(1) can be used to examine the results.

moncontrol() 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().

FILES

gmon.progname.pid.out

execution data file

SEE ALSO

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

CAVEATS

Do not call moncontrol(0) if pthread_create(3) will be called subsequently. While profiling is stopped, pthread_create(3) does not allocate the collection buffer for the new thread. This cannot be recovered by moncontrol(1), resulting in failure to collect the statistics for those threads.