MONITOR(3) 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 monitor with default parameters; monitor needn't be called explicitly except to gain fine control over profiling. Monitor is an interface to profil(2). Lowpc and highpc are the addresses of two functions; buffer is the address of a (user supplied) array of bufsize bytes. Monitor arranges to record a histogram of periodically sampled values of the program counter, and of counts of calls of certain func- tions, in the buffer. The lowest address sampled is that of lowpc and the highest is just below highpc. At most nfunc call counts can be kept; only calls of functions compiled with the profiling option -p of cc(1) are recorded. 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. The default values for bufsize and nfunc are (highpc-lowpc)/8 and 300 respectively. To profile the entire program, use extern etext(); . . . monitor((int (*)())2, etext, buf, bufsize, nfunc); Etext lies just above all the program text, see end(3). For the highest resolution profiling on the VAX, use bufsize = ((int)highpc)-((int)lowpc)+12+8*nfunc. To stop execution monitoring and write the results on the file mon.out, use monitor((int (*)())0); then prof(1) can be used to examine the results. FILES prof(1), profil(2), cc(1)