jdk

1
.\" Copyright (c) 2004, 2018, Oracle and/or its affiliates. All rights reserved.
2
.\" DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3
.\"
4
.\" This code is free software; you can redistribute it and/or modify it
5
.\" under the terms of the GNU General Public License version 2 only, as
6
.\" published by the Free Software Foundation.
7
.\"
8
.\" This code is distributed in the hope that it will be useful, but WITHOUT
9
.\" ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10
.\" FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
11
.\" version 2 for more details (a copy is included in the LICENSE file that
12
.\" accompanied this code).
13
.\"
14
.\" You should have received a copy of the GNU General Public License version
15
.\" 2 along with this work; if not, write to the Free Software Foundation,
16
.\" Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17
.\"
18
.\" Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19
.\" or visit www.oracle.com if you need additional information or have any
20
.\" questions.
21
.\"
22
.\" Automatically generated by Pandoc 2.19.2
23
.\"
24
.\" Define V font for inline verbatim, using C font in formats
25
.\" that render this, and otherwise B font.
26
.ie "\f[CB]x\f[R]"x" \{\
27
. ftr V B
28
. ftr VI BI
29
. ftr VB B
30
. ftr VBI BI
31
.\}
32
.el \{\
33
. ftr V CR
34
. ftr VI CI
35
. ftr VB CB
36
. ftr VBI CBI
37
.\}
38
.TH "JMAP" "1" "2025" "JDK 24-ea" "JDK Commands"
39
.hy
40
.SH NAME
41
.PP
42
jmap - print details of a specified process
43
.SH SYNOPSIS
44
.PP
45
\f[B]Note:\f[R] This command is experimental and unsupported.
46
.PP
47
\f[V]jmap\f[R] [\f[I]options\f[R]] \f[I]pid\f[R]
48
.TP
49
\f[I]options\f[R]
50
This represents the \f[V]jmap\f[R] command-line options.
51
See \f[B]Options for the jmap Command\f[R].
52
.TP
53
\f[I]pid\f[R]
54
The process ID for which the information specified by the
55
\f[I]options\f[R] is to be printed.
56
The process must be a Java process.
57
To get a list of Java processes running on a machine, use either the
58
\f[V]ps\f[R] command or, if the JVM processes are not running in a
59
separate docker instance, the \f[B]jps\f[R] command.
60
.SH DESCRIPTION
61
.PP
62
The \f[V]jmap\f[R] command prints details of a specified running
63
process.
64
.PP
65
\f[B]Note:\f[R]
66
.PP
67
This command is unsupported and might not be available in future
68
releases of the JDK.
69
On Windows Systems where the \f[V]dbgeng.dll\f[R] file isn\[aq]t
70
present, the Debugging Tools for Windows must be installed to make these
71
tools work.
72
The \f[V]PATH\f[R] environment variable should contain the location of
73
the \f[V]jvm.dll\f[R] file that\[aq]s used by the target process or the
74
location from which the core dump file was produced.
75
.SH OPTIONS FOR THE JMAP COMMAND
76
.TP
77
\f[V]-clstats\f[R] \f[I]pid\f[R]
78
Connects to a running process and prints class loader statistics of Java
79
heap.
80
.TP
81
\f[V]-finalizerinfo\f[R] \f[I]pid\f[R]
82
Connects to a running process and prints information on objects awaiting
83
finalization.
84
.TP
85
\f[V]-histo\f[R][\f[V]:live\f[R]] \f[I]pid\f[R]
86
Connects to a running process and prints a histogram of the Java object
87
heap.
88
If the \f[V]live\f[R] suboption is specified, it then counts only live
89
objects.
90
.TP
91
\f[V]-dump:\f[R]\f[I]dump_options\f[R] \f[I]pid\f[R]
92
Connects to a running process and dumps the Java heap.
93
The \f[I]dump_options\f[R] include:
94
.RS
95
.IP \[bu] 2
96
\f[V]live\f[R] --- When specified, dumps only the live objects; if not
97
specified, then dumps all objects in the heap.
98
.IP \[bu] 2
99
\f[V]format=b\f[R] --- Dumps the Java heap in \f[V]hprof\f[R] binary
100
format
101
.IP \[bu] 2
102
\f[V]file=\f[R]\f[I]filename\f[R] --- Dumps the heap to
103
\f[I]filename\f[R]
104
.PP
105
Example: \f[V]jmap -dump:live,format=b,file=heap.bin\f[R] \f[I]pid\f[R]
106
.RE
107