[unix-history] / usr / man / man3 / monitor.3

.TH MONITOR 3  "19 January 1983"
.UC 4
.SH NAME
monitor, monstartup, moncontrol \- prepare execution profile
.SH SYNOPSIS
.nf
.B monitor(lowpc, highpc, buffer, bufsize, nfunc)
.B int (*lowpc)(), (*highpc)();
.B short buffer[];
.sp
.B monstartup(lowpc, highpc)
.B int (*lowpc)(), (*highpc)();
.sp
.B moncontrol(mode)
.fi
.SH DESCRIPTION
There are two different forms of monitoring available:
An executable program created by:
.IP  "	cc \-p . . ."
.LP
automatically includes calls for the 
.IR prof (1)
monitor and includes an initial call to its start-up routine
.I monstartup
with default parameters;
.I monitor
need not be called explicitly except to gain fine control over profil 
buffer allocation.
An executable program created by:
.IP  "	cc \-pg . . ."
.LP
automatically includes calls for the
.IR gprof (1)
monitor.
.PP
.I Monstartup
is a high level interface to
.IR profil (2).
.I Lowpc
and
.I highpc
specify the address range that is to be sampled; the lowest address sampled
is that of
.I lowpc
and the highest is just below
.IR highpc .
.I Monstartup
allocates space using 
.IR sbrk (2)
and passes it to
.I monitor
(see below) to record a histogram of periodically sampled values of
the program counter, and of counts of calls of certain functions, in the buffer.
Only calls of functions compiled with the profiling option
.B \-p
of
.IR cc (1)
are recorded.
.PP
To profile the entire program, it is sufficient to use
.PP
.nf
	extern etext();
	. . .
	monstartup((int) 2, etext);
.fi
.PP
.I Etext
lies just above all the program text, see
.IR end (3).
.PP
To stop execution monitoring and write the results on the file
.I mon.out,
use
.PP
	monitor(0);
.LP
then
.IR prof (1)
can be used to examine the results.
.PP
.I Moncontrol
is used to selectively control profiling within a program.
This works with either 
.IR prof (1)
or
.IR gprof (1)
type profiling.
When the program starts, profiling begins.
To stop the collection of histogram ticks and call counts use
.IR moncontrol (0);
to resume the collection of histogram ticks and call counts use
.IR moncontrol (1).
This allows the cost of particular operations to be measured.
Note that an output file will be produced upon program exit
irregardless of the state of 
.I moncontrol.
.PP
.I Monitor
is a low level interface to
.IR profil (2).
.I Lowpc
and
.I highpc
are the addresses of two functions;
.I buffer
is the address of a (user supplied) array of
.I bufsize
short integers.  At most
.I nfunc
call counts can be kept.
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.
.I Monitor
divides the buffer into space to record the histogram
of program counter samples over the range
.I lowpc
to
.IR highpc ,
and space to record call counts of functions compiled with the 
.B \-p
option to
.IR cc (1).
.PP
To profile the entire program, it is sufficient to use
.PP
.nf
	extern etext();
	. . .
	monitor((int) 2, etext, buf, bufsize, nfunc);
.fi
.SH FILES
mon.out
.SH "SEE ALSO"
cc(1), prof(1), gprof(1), profil(2), sbrk(2)
Commit	Line	Data
6a1b5fe7 C	1	.TH MONITOR 3 "19 January 1983"
	2	.UC 4
	3	.SH NAME
	4	monitor, monstartup, moncontrol \- prepare execution profile
	5	.SH SYNOPSIS
	6	.nf
	7	.B monitor(lowpc, highpc, buffer, bufsize, nfunc)
	8	.B int (lowpc)(), (highpc)();
	9	.B short buffer[];
	10	.sp
	11	.B monstartup(lowpc, highpc)
	12	.B int (lowpc)(), (highpc)();
	13	.sp
	14	.B moncontrol(mode)
	15	.fi
	16	.SH DESCRIPTION
	17	There are two different forms of monitoring available:
	18	An executable program created by:
	19	.IP " cc \-p . . ."
	20	.LP
	21	automatically includes calls for the
	22	.IR prof (1)
	23	monitor and includes an initial call to its start-up routine
	24	.I monstartup
	25	with default parameters;
	26	.I monitor
	27	need not be called explicitly except to gain fine control over profil
	28	buffer allocation.
	29	An executable program created by:
	30	.IP " cc \-pg . . ."
	31	.LP
	32	automatically includes calls for the
	33	.IR gprof (1)
	34	monitor.
	35	.PP
	36	.I Monstartup
	37	is a high level interface to
	38	.IR profil (2).
	39	.I Lowpc
	40	and
	41	.I highpc
	42	specify the address range that is to be sampled; the lowest address sampled
	43	is that of
	44	.I lowpc
	45	and the highest is just below
	46	.IR highpc .
	47	.I Monstartup
	48	allocates space using
	49	.IR sbrk (2)
	50	and passes it to
	51	.I monitor
	52	(see below) to record a histogram of periodically sampled values of
	53	the program counter, and of counts of calls of certain functions, in the buffer.
	54	Only calls of functions compiled with the profiling option
	55	.B \-p
	56	of
	57	.IR cc (1)
	58	are recorded.
	59	.PP
	60	To profile the entire program, it is sufficient to use
	61	.PP
	62	.nf
	63	extern etext();
	64	. . .
65	monstartup((int) 2, etext);
66	.fi
67	.PP
68	.I Etext
69	lies just above all the program text, see
70	.IR end (3).
71	.PP
72	To stop execution monitoring and write the results on the file
73	.I mon.out,
74	use
75	.PP
76	monitor(0);
77	.LP
78	then
79	.IR prof (1)
80	can be used to examine the results.
81	.PP
82	.I Moncontrol
83	is used to selectively control profiling within a program.
84	This works with either
85	.IR prof (1)
86	or
87	.IR gprof (1)
88	type profiling.
89	When the program starts, profiling begins.
90	To stop the collection of histogram ticks and call counts use
91	.IR moncontrol (0);
92	to resume the collection of histogram ticks and call counts use
93	.IR moncontrol (1).
94	This allows the cost of particular operations to be measured.
95	Note that an output file will be produced upon program exit
96	irregardless of the state of
97	.I moncontrol.
98	.PP
99	.I Monitor
100	is a low level interface to
101	.IR profil (2).
102	.I Lowpc
103	and
104	.I highpc
105	are the addresses of two functions;
106	.I buffer
107	is the address of a (user supplied) array of
108	.I bufsize
109	short integers. At most
110	.I nfunc
111	call counts can be kept.
112	For the results to be significant, especially where there are small, heavily
113	used routines, it is suggested that the buffer be no more
114	than a few times smaller than the range of locations sampled.
115	.I Monitor
116	divides the buffer into space to record the histogram
117	of program counter samples over the range
118	.I lowpc
119	to
120	.IR highpc ,
121	and space to record call counts of functions compiled with the
122	.B \-p
123	option to
124	.IR cc (1).
125	.PP
126	To profile the entire program, it is sufficient to use
127	.PP
128	.nf
129	extern etext();
130	. . .
131	monitor((int) 2, etext, buf, bufsize, nfunc);
132	.fi
133	.SH FILES
134	mon.out
135	.SH "SEE ALSO"
136	cc(1), prof(1), gprof(1), profil(2), sbrk(2)