profil(2)                           CLIX                           profil(2)



  NAME

    profil - Execution time profile

  LIBRARY

    Standard C Library (libc.a)

  SYNOPSIS

    void profil(
      char *buff ,
      int bufsiz ,
      int offset ,
      int scale );

  PARAMETERS

    buff    Specifies the address of the first profiling location.

    bufsiz  Specifies the size in bytes of the profiling buffer.

    offset  Specifies the base of the range of PCs to profile.

    scale   Specifies the number of PCs grouped into a single profiling entry.

  DESCRIPTION

    The profil() function allows a program to obtain a histogram with program
    execution locality.  The buff variable points to an area of memory whose
    length (in bytes) is given by bufsiz.  After this call, the user's program
    counter (pc) is examined for each clock tick.  Then the value of offset is
    subtracted from the pc, and the remainder is multiplied by scale.  If the
    resulting number corresponds to an entry inside buff, that entry is
    incremented.  An entry is defined as a series of bytes with length
    sizeof(short).

    The scale is interpreted as an unsigned, fixed-point fraction with binary
    point at the left: 0177777 (octal) gives a one-to-one mapping of pc's to
    entries in buff; 077777 (octal) maps each pair of instruction entries
    together.  02(octal) maps all instructions onto the beginning of buff
    (producing a non-interrupting core clock).

    Profiling is turned off by giving a scale of 0 or 1.  It is rendered
    ineffective by giving a bufsiz of 0.  Profiling is turned off when an
    exec() function is run, but remains on in both child and parent after a
    fork() function call.  Profiling will be turned off if an update in buff
    would cause a memory fault.

  EXAMPLES




  2/94 - Intergraph Corporation                                              1

  profil(2)                           CLIX                           profil(2)



    To profile execution of the first 4 kilobytes of a process' text area into
    4 separate profiling locations:

    short profil_buf[4];
    profil(profil_buf, 4 * sizeof(short), text_start, 0100);


  RETURN VALUES

    Not defined.

  RELATED INFORMATION

    Commands:  prof(1)

    Functions:  times(2), monitor(3)






































  2                                              Intergraph Corporation - 2/94