.\"	@(#) a64l.so.1 
.\"
.TH libprof.so.1 1 
.AT 3
.SH NAME
libprof.so.1 \- shared library to profile functions in libc

.SH SYNOPSIS
.B LD_PRELOAD=./libprof.so.1 
program [args] ...
.sp 0
.SH DESCRIPTION
.I libprof
intercepts calls to libc and reports their cpu-time usage.
.PP
This is used to identify hot-spots in library usage by a program,
like the 
.I prof
source-code profiler. Unlike the source profiler, libprof doesn't
require recompilation, but works on unmodified binaries.
.PP

When loaded with a program, it emits a time profile, such as:
.nj
.nf
Name                           Duration   Pct.        Calls Sec/Call
----                           ---------- ----        ----- ----------
Entire program                 0.23329523 100.0           1 0.23329523
a64l                           0.11952140 51.23      100000 0.00000120
addseverity                    0.01279909  5.56           1 0.01279909
Measurement overhead           0.00031536  0.14           1 0.00031536

.ju
.fi

.PP
This is sorted from largest to smallest duration, always beginning with
an entry for the whole program. One of the entries reports on the
(measurement) overhead of the libprof library.
.PP
If the program profiled is a shell script, one profile per binary
program is emitted, labelled with the pid of the program. 
.I ptree
(1) can be used to clarify which pid(s) are of interest.

.SH FILES
.sp 0

.SH "SEE ALSO"
truss -c (1), prof(1).

.SH BUGS
Not thread-aware, so that two threads entering the same 
function at once can clash. On Solaris this causes an
assertion failure and the program being tested to
hang in lwp_park. This is known to apply to
.nf
.nj
	mozilla
	acroread 5
	gij
	intop
	ntop
	rmic
	svn
	wish
.fi
.ju
.for example, pstack shows mozilla hung in lwp_park, thusly
.nf
.nj
698:	/usr/local/mozilla/mozilla-bin
 ff2c5f88 lwp_park (0, 0, 0)
 ff2c1d00 mutex_lock_queue (ff2d8b84, 0, ff23fbc8, ff2d8000, ff3d90d4, ff3ec7ac) + 104
 ff2c2700 slow_lock (ff23fbc8, fed30000, 0, 0, ff3c4ed8, 0) + 58
 ff1faeec dgettext (ff227e30, ff227e40, ff3ef288, ff23c000, 1, 0) + 24
 ff1b5ed4 _assert  (ff376648, ff376658, 1da, ff216b4c, 0, 0) + 18
 ff324bb0 calloc   (1, 18, 0, 0, 0, 0) + b8
 ff1faf08 dgettext (ff227e30, ff227e40, 0, ff23c000, 0, 0) + 40
 ff1b5ed4 _assert  (ff377928, ff377938, b52, 0, 0, 0) + 18
 ff3349ec getenv   (ff2c6570, 1e454, 0, 8, ff3bb7b8, 0) + b4
 ff2b9bc0 envvar   (ff2c6570, f4240, 0, fffffff8, 0, ffbfe791) + 18
 ff2b9ed4 _lib_init (ff3ed7b8, 0, ff3ec204, 3127c, ff3c3068, 0) + 290
 ff2c6270 _init    (ff3ec0c0, ff2a1cec, 18, fe801548, 2, ff3ec7ac) + 4
 ff3bf228 call_init (fe801f70, 0, fe801f70, ffdfffff, 400000, 80000) + 1c0
 ff3be7fc setup    (ffbfee5c, ff3ec194, 10000, 0, ff3ec000, 0) + 135c
 ff3cc400 _setup   (e265, a, a, ffbfffce, ffbfffda, ff3cc03c) + 3a8
 ff3b3994 _rt_boot (0, 0, 0, 0, 0, 0) + 88
 00000000 ???????? (0, 0, 0, 0, 0, 0)
.fi
.ju
.PP
Doesn't allow turning off headers. Doesn't allow sorting by 
calls column (use sort -k 4rn) or by seconds/call
(use sort -k 5rn).
.PP
Cannot report interim results in sorted order (sorting invalidates
further data collection).