MONITOR(3)          UNIX Programmer's Manual           MONITOR(3)

NAME
     monitor - prepare execution profile

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

DESCRIPTION
     An executable program created by `cc -p' automatically
     includes calls for _m_o_n_i_t_o_r with default parameters; _m_o_n_i_t_o_r
     needn't be called explicitly except to gain fine control
     over profiling.

     _M_o_n_i_t_o_r is an interface to _p_r_o_f_i_l(2).  _L_o_w_p_c and _h_i_g_h_p_c are
     the addresses of two functions; _b_u_f_f_e_r is the address of a
     (user supplied) array of _b_u_f_s_i_z_e short integers.  _M_o_n_i_t_o_r
     arranges to record a histogram of periodically sampled
     values of the program counter, and of counts of calls of
     certain functions, in the buffer.  The lowest address sam-
     pled is that of _l_o_w_p_c and the highest is just below _h_i_g_h_p_c.
     At most _n_f_u_n_c call counts can be kept; only calls of func-
     tions compiled with the profiling option -p of _c_c(1) are
     recorded.  For the results to be significant, especially
     where there are small, heavily used routines, it is sug-
     gested that the buffer be no more than a few times smaller
     than the range of locations sampled.

     To profile the entire program, it is sufficient to use

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

     _E_t_e_x_t lies just above all the program text, see _e_n_d(3).

     To stop execution monitoring and write the results on the
     file _m_o_n._o_u_t, use

          monitor(0);

     then _p_r_o_f(1) can be used to examine the results.

FILES
     mon.out

SEE ALSO
     cc(1), prof(1), profil(2)

Printed 5/17/83                                                 1