Unix/Linux Go Back    


BSD 2.11 - man page for monitor (bsd section 3)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)


MONITOR(3)									       MONITOR(3)

NAME
       monitor, monstartup, moncontrol - prepare execution profile

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

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

       moncontrol(mode)

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

	    cc -p . . .

       automatically  includes	calls for the prof(1) monitor and includes an initial call to its
       start-up routine monstartup with default parameters; monitor need not be called explicitly
       except  to gain fine control over profil buffer allocation.  An executable program created
       by:

	    cc -pg . . .

       automatically includes calls for the gprof(1) 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  com-
       piled 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(3).

       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.

       Moncontrol  is  used  to  selectively control profiling within a program.  This works with
       either prof(1) or gprof(1) type profiling.  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 allows the cost  of
       particular operations to be measured.  Note that an output file will be produced upon pro-
       gram exit irregardless of the state of moncontrol.

       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 call 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 space to record call counts of functions compiled with the -p option to 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), sbrk(2)

4th Berkeley Distribution		   May 15, 1985 			       MONITOR(3)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums


All times are GMT -4. The time now is 08:08 PM.