1#!/usr/sbin/dtrace -Zs
2/*
3 * js_objgc.d - trace JavaScript Object GC using DTrace.
4 *              Written for the JavaScript DTrace provider.
5 *
6 * $Id: js_objgc.d 63 2007-10-04 04:34:38Z brendan $
7 *
8 * This traces JavaScript activity from all running browers on the system
9 * which support the JavaScript DTrace provider.
10 *
11 * USAGE: js_objgc.d		# hit Ctrl-C to end
12 *
13 * FIELDS:
14 *		FILE		Filename that contained the function
15 *		CLASS		Class to which this new object belongs
16 *		TOTAL		Object entropy (positive == uncollected)
17 *
18 * This script provides information on which objects are not being garbage
19 * collected, an issue which causes the browser to steadily leak memory.
20 * We trace object creation (+1) and destruction (-1), and provide a
21 * summary each second of the running tally of the object class and
22 * originating filename. If over the period of several minutes an object
23 * type is still steadily increasing, then that would be of interest.
24 * Be patient, depending on the rate of object creation it can take over
25 * ten minutes for garbage collect to kick in.
26 *
27 * NOTES:
28 * - it is possible that you will see negative entropy. That happens
29 * when you begin tracing after some objects have already been created,
30 * and then trace their destruction.
31 * - there are other Things that GC handles, other than Objects; extra
32 * probes can be added to trace them, should the need arise.
33 *
34 * COPYRIGHT: Copyright (c) 2007 Brendan Gregg.
35 *
36 * CDDL HEADER START
37 *
38 *  The contents of this file are subject to the terms of the
39 *  Common Development and Distribution License, Version 1.0 only
40 *  (the "License").  You may not use this file except in compliance
41 *  with the License.
42 *
43 *  You can obtain a copy of the license at Docs/cddl1.txt
44 *  or http://www.opensolaris.org/os/licensing.
45 *  See the License for the specific language governing permissions
46 *  and limitations under the License.
47 *
48 * CDDL HEADER END
49 *
50 * 09-Sep-2007	Brendan Gregg	Created this.
51 */
52
53/* if you get dynvardrops, increase this, */
54#pragma D option dynvarsize=32m
55#pragma D option quiet
56
57dtrace:::BEGIN
58{
59	printf("Tracing... Hit Ctrl-C to end.\n");
60}
61
62javascript*:::object-create
63/arg2/
64{
65	this->file = basename(copyinstr(arg0));
66	@objs[this->file, copyinstr(arg1)] = sum(1);
67	filename[arg2] = this->file;
68}
69
70javascript*:::object-finalize
71/filename[arg2] == NULL/
72{
73	@objs["<missed>", copyinstr(arg1)] = sum(-1);
74}
75
76javascript*:::object-finalize
77/filename[arg2] != NULL/
78{
79	@objs[filename[arg2], copyinstr(arg1)] = sum(-1);
80	filename[arg2] = 0;
81}
82
83profile:::tick-1sec,
84dtrace:::END
85{
86	printf("\n %-24s %8s %-20s %23Y\n", "FILE", "TOTAL", "CLASS",
87	    walltimestamp);
88	printa(" %-24.24s %@8d %s\n", @objs);
89}
90