monstartup(3) [netbsd man page]
MONCONTROL(3) BSD Library Functions Manual MONCONTROL(3) NAME
moncontrol, monstartup -- control execution profile LIBRARY
Standard C Library (libc, -lc) SYNOPSIS
moncontrol(int mode); monstartup(u_long *lowpc, u_long *highpc); DESCRIPTION
An executable program compiled using the -pg option to cc(1) automatically includes calls to collect statistics for the gprof(1) call-graph execution profiler. In typical operation, profiling begins at program startup and ends when the program calls exit. When the program exits, the profiling data are written to the file gmon.out, then gprof(1) can be used to examine the results. moncontrol() selectively controls profiling within a program. When the program starts, profiling begins. To stop the collection of his- togram ticks and call counts use moncontrol(0); to resume the collection of histogram ticks and call counts use moncontrol(1). This feature allows the cost of particular operations to be measured. Note that an output file will be produced on program exit regardless of the state of moncontrol(). Programs that are not loaded with -pg may selectively collect profiling statistics by calling monstartup() with the range of addresses to be profiled. 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. Only functions in that range that have been compiled with the -pg option to cc(1) will appear in the call graph part of the output; however, all functions in that address range will have their execution time measured. Profiling begins on return from monstartup(). ENVIRONMENT
PROFDIR Directory to place the output file(s) in. When this is set, instead of writing the profiling output to gmon.out, a filename is gen- erated from the process id and name of the program (e.g., 123.a.out). If you are profiling a program that forks, or otherwise cre- ates multiple copies, setting this is the only reasonable way to get all profiling data. FILES
gmon.out execution data file SEE ALSO
cc(1), gprof(1), profil(2) BSD
June 4, 1993 BSD
Check Out this Related Man Page
monitor(3) Library Functions Manual 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 These functions use the system call to control program-counter sampling. Using the option -p when compiling or linking a program automati- cally generates calls to these functions. You do need not to call these functions explicitly unless you want more control. Typically, you would call either or to initialize pc-sampling and enable it; call to disable or reenable it; and call at the end of execu- tion to disable sampling and record the samples in a file. Your initial call to enables pc-sampling. The parameters lowpc and highpc specify the range of addresses to be sampled. The lowest address is that of lowpc and the highest is just below highpc. The buffer parameter is the address of a (user allocated) array of bufsize short integers, which holds a record of the samples; for best results, the buffer should not be less than a few times smaller than the range of addresses sampled. The nfunc parameter is ignored. The environment variable PROFDIR determines the name of the output file and whether pc-sampling takes place: if it is not set, the file is named mon.out; if set to the empty string, no pc-sampling occurs; if set to a non-empty string, the file is named string/pid.progname, where pid is the process id of the executing program and progname is the program's name as it appears in argv[0]. The subdirectory string must already exist. To profile the entire program, use the following: extern eprol(), etext(); . . . monitor(eprol, etext, buf, bufsize, 0); The routine lies just below the user program text, and lies just above it, as described in (Because the user program does not necessarily start at a low memory address, using a small number in place of is dangerous). The routine is an alternate form of that calls (see for you to allocate the buffer. The function selectively disables and re-enables pc-sampling within a program, allowing you to measure the cost of particular operations. The function disables pc-sampling, and reenables it. To stop execution monitoring and write the results in the output file, use the following: monitor(0); Files mon.out default name for output file libprof1.a routines for pc-sampling See Also cc(1), ld(1), profil(2), brk(2) RISC monitor(3)