moncontrol(3) - NetBSD Manual Pages

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MONCONTROL(3)           NetBSD Library Functions Manual          MONCONTROL(3)


NAME

     moncontrol, monstartup -- control execution profile


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     moncontrol(int mode);

     monstartup(u_long *lowpc, u_long *highpc);


DESCRIPTION

     An executable program compiled using the -pg option to cc(1) automati-
     cally 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 his-
     togram 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 pro-
     filed.  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().


ENVIRONMENT

     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 oth-
              erwise creates multiple copies, setting this is the only reason-
              able way to get all profiling data.


FILES

     gmon.out  execution data file


SEE ALSO

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

NetBSD 3.0.1                     June 4, 1993                     NetBSD 3.0.1