MONITOR(3C)             COMMAND REFERENCE             MONITOR(3C)



NAME
     monitor, monstartup - prepare execution profile

SYNOPSIS
     monitor(lowpc, highpc, buffer, bufsize, nfunc)
     int (*lowpc)(), (*highpc)();
     short buffer[];

     monstartup(lowpc, highpc)
     int (*lowpc)(), (*highpc)();

DESCRIPTION
     There are two different forms of monitoring available.  An
     executable program created by:

          cc -p . . .

     automatically includes calls for monstartup with default
     parameters; monitor need not be called explicitly except to
     gain fine control over profiling.  An executable program
     created by:

          cc -pg . . .

     obtains a different monitor.

     Monstartup is a high level interface to profil(2). 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.  Monstartup allocates space using sbrk(2)
     and passes it to monitor (see below) to record a histogram
     of periodically sampled values of the program counter, and
     of counts of calls of certain functions, in the buffer.
     Only calls of functions compiled with the profiling option
     -p of cc(1) are recorded.

     To profile the entire program, it is sufficient to use

          extern etext();
          monstartup((int) 2, etext);

     Etext lies just above all the program text, see end(3c).

     To stop execution monitoring and write the results on the
     file mon.out, use

          monitor(0)

     Then
     prof(1)
     can be used to examine the results.




Printed 3/13/89                                                 1

MONITOR(3C)             COMMAND REFERENCE             MONITOR(3C)



     Monitor
     is a low level interface to
     profil(2).
     Lowpc
     and
     highpc
     are the addresses of two functions;
     buffer
     is the address of a (user supplied) array of
     bufsize
     short integers. At most
     nfunc
     calls, counts can be kept.
     For the results to be significant, especially where there are small, heavily
     used routines, it is suggested that the buffer be no more
     than a few times smaller than the range of locations sampled.
     Monitor
     divides the buffer into space to record the histogram
     of program counter samples over the range
     lowpc
     to
     highpc,
     and spaces to record call counts of functions compiled with the
     -p
     option of
     cc(1).

     To profile the entire program, it is sufficient to use

          extern etext();
          monitor((int) 2, etext, buf, bufsize, nfunc);

FILES
     mon.out

SEE ALSO
     cc(1), prof(1), gprof(1), profil(2), and sbrk(2).


















Printed 3/13/89                                                 2

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sy:435,1583;
de:2018,2037;4463,1154;
fi:5617,82;
se:5699,201;
%%index%%000000000106