moncontrol, monstartup - control execution profile
Standard C Library (libc, -lc)
moncontrol(int mode);
monstartup(u_long *lowpc, u_long *highpc);
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 gmon.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().
Programs that are not loaded with -pg may selectively collect profiling
statistics by calling monstartup() with the range of addresses to be profiled.
lowpc and highpc 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().
PROFDIR Directory to place the output file(s) in. When this is set,
instead of writing the profiling output to gmon.out, a filename
is generated from the process id and name of the program. (e.g.
123.a.out) If you are profiling a program that forks, or otherwise
creates multiple copies, setting this is the only reasonable
way to get all profiling data.
gmon.out execution data file
cc(1), gprof(1), profil(2)
BSD June 4, 1993 BSD
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