/*
* Copyright (c) 2005, 2021, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.tools.jmap;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.Collection;
import com.sun.tools.attach.VirtualMachine;
import com.sun.tools.attach.AttachNotSupportedException;
import sun.tools.attach.HotSpotVirtualMachine;
import sun.tools.common.ProcessArgumentMatcher;
import static java.nio.charset.StandardCharsets.UTF_8;
/*
* This class is the main class for the JMap utility. It parses its arguments
* and decides if the command should be satisfied using the VM attach mechanism
* or an SA tool. At this time the only option that uses the VM attach mechanism
* is the -dump option to get a heap dump of a running application. All other
* options are mapped to SA tools.
*/
public class JMap {
public static void main(String[] args)
throws Exception {
if (args.length == 0) {
usage(1);
// no arguments
}
checkForUnsupportedOptions(args);
// the chosen option
String option =
null;
// First iterate over the options (arguments starting with -). There should be
// one.
int optionCount = 0;
while (optionCount < args.length) {
String arg = args[optionCount];
if (!arg.startsWith(
"-")) {
break;
}
if (arg.equals(
"-?") ||
arg.equals(
"-h") ||
arg.equals(
"--help") ||
// -help: legacy. Undocumented.
arg.equals(
"-help")) {
usage(0);
}
else {
if (option !=
null) {
usage(1);
// option already specified
}
option = arg;
}
optionCount++;
}
// if no option provided then use default.
if (option ==
null) {
usage(0);
}
// Next we check the parameter count.
int paramCount = args.length - optionCount;
if (paramCount != 1) {
usage(1);
}
String pidArg = args[1];
// Here we handle the built-in options
// As more options are added we should create an abstract tool class and
// have a table to map the options
ProcessArgumentMatcher ap =
new ProcessArgumentMatcher(pidArg);
Collection<String> pids = ap.getVirtualMachinePids(JMap.
class);
if (pids.isEmpty()) {
System.err.println(
"Could not find any processes matching : '" + pidArg +
"'");
System.exit(1);
}
for (String pid : pids) {
if (pids.size() > 1) {
System.out.println(
"Pid:" + pid);
}
if (option.equals(
"-histo")) {
histo(pid,
"");
}
else if (option.startsWith(
"-histo:")) {
histo(pid, option.substring(
"-histo:".length()));
}
else if (option.startsWith(
"-dump:")) {
dump(pid, option.substring(
"-dump:".length()));
}
else if (option.equals(
"-finalizerinfo")) {
executeCommandForPid(pid,
"jcmd",
"GC.finalizer_info");
}
else if (option.equals(
"-clstats")) {
executeCommandForPid(pid,
"jcmd",
"VM.classloader_stats");
}
else {
usage(1);
}
}
}
private static void executeCommandForPid(String pid, String command, Object ... args)
throws AttachNotSupportedException, IOException {
VirtualMachine vm = VirtualMachine.attach(pid);
// Cast to HotSpotVirtualMachine as this is an
// implementation specific method.
HotSpotVirtualMachine hvm = (HotSpotVirtualMachine) vm;
try (InputStream in = hvm.executeCommand(command, args)) {
// read to EOF and just print output
byte b[] =
new byte[256];
int n;
do {
n = in.read(b);
if (n > 0) {
String s =
new String(b, 0, n, UTF_8);
System.out.print(s);
}
}
while (n > 0);
}
vm.detach();
}
private static String parseFileName(String opt) {
// opt starts with "file="
if (opt.length() > 5) {
// pass whole "file=" string
String filename = opt.substring(5);
try {
// Get the canonical path - important to avoid just
// passing a "heap.bin" and having the dump created
// in the target VM working directory rather than the
// directory where jmap is executed.
return new File(filename).getCanonicalPath();
}
catch (IOException ioe) {
return null;
}
}
// no filename
return null;
}
private static void histo(String pid, String options)
throws AttachNotSupportedException, IOException {
String liveopt =
"-all";
String filename =
null;
String parallel =
null;
String subopts[] = options.split(
",");
for (String subopt : subopts) {
if (subopt.equals(
"") || subopt.equals(
"all")) {
// pass
}
else if (subopt.equals(
"live")) {
liveopt =
"-live";
}
else if (subopt.startsWith(
"file=")) {
filename = parseFileName(subopt);
if (filename ==
null) {
System.err.println(
"Fail: invalid option or no file name '" + subopt +
"'");
usage(1);
}
}
else if (subopt.startsWith(
"parallel=")) {
parallel = subopt.substring(
"parallel=".length());
if (parallel ==
null) {
System.err.println(
"Fail: no number provided in option: '" + subopt +
"'");
usage(1);
}
}
else {
System.err.println(
"Fail: invalid option: '" + subopt +
"'");
usage(1);
}
}
System.out.flush();
// inspectHeap is not the same as jcmd GC.class_histogram
executeCommandForPid(pid,
"inspectheap", liveopt, filename, parallel);
}
private static void dump(String pid, String options)
throws AttachNotSupportedException, IOException {
String subopts[] = options.split(
",");
String filename =
null;
String liveopt =
"-all";
String compress_level =
null;
for (String subopt : subopts) {
if (subopt.equals(
"") || subopt.equals(
"all")) {
// pass
}
else if (subopt.equals(
"live")) {
liveopt =
"-live";
}
else if (subopt.startsWith(
"file=")) {
filename = parseFileName(subopt);
if (filename ==
null) {
System.err.println(
"Fail: invalid option or no file name '" + subopt +
"'");
usage(1);
}
}
else if (subopt.equals(
"format=b")) {
// ignore format (not needed at this time)
}
else if (subopt.startsWith(
"gz=")) {
compress_level = subopt.substring(
"gz=".length());
if (compress_level.length() == 0) {
System.err.println(
"Fail: no number provided in option: '" + subopt +
"'");
usage(1);
}
}
else {
System.err.println(
"Fail: invalid option: '" + subopt +
"'");
usage(1);
}
}
if (filename ==
null) {
System.err.println(
"Fail: invalid option or no file name");
usage(1);
}
System.out.flush();
// dumpHeap is not the same as jcmd GC.heap_dump
executeCommandForPid(pid,
"dumpheap", filename, liveopt, compress_level);
}
private static void checkForUnsupportedOptions(String[] args) {
// Check arguments for -F, -m, and non-numeric value
// and warn the user that SA is not supported anymore
int paramCount = 0;
for (String s : args) {
if (s.equals(
"-F")) {
SAOptionError(
"-F option used");
}
if (s.equals(
"-heap")) {
SAOptionError(
"-heap option used");
}
/* Reimplemented using jcmd, output format is different
from original one
if (s.equals("-clstats")) {
warnSA("-clstats option used");
}
if (s.equals("-finalizerinfo")) {
warnSA("-finalizerinfo option used");
}
*/
if (! s.startsWith(
"-")) {
paramCount += 1;
}
}
if (paramCount > 1) {
SAOptionError(
"More than one non-option argument");
}
}
private static void SAOptionError(String msg) {
System.err.println(
"Error: " + msg);
System.err.println(
"Cannot connect to core dump or remote debug server. Use jhsdb jmap instead");
System.exit(1);
}
// print usage message
private static void usage(
int exit) {
System.err.println(
"Usage:");
System.err.println(
" jmap -clstats ");
System.err.println(
" to connect to running process and print class loader statistics");
System.err.println(
" jmap -finalizerinfo ");
System.err.println(
" to connect to running process and print information on objects awaiting finalization");
System.err.println(
" jmap -histo[:[]] ");
System.err.println(
" to connect to running process and print histogram of java object heap");
System.err.println(
" jmap -dump: ");
System.err.println(
" to connect to running process and dump java heap");
System.err.println(
" jmap -? -h --help");
System.err.println(
" to print this help message");
System.err.println(
"");
System.err.println(
" dump-options:");
System.err.println(
" live dump only live objects (takes precedence if both \"live\
" and \"all\
" are specified)");
System.err.println(
" all dump all objects in the heap (default if one of \"live\
" or \"all\
" is not specified)");
System.err.println(
" format=b binary format");
System.err.println(
" file= dump heap to ");
System.err.println(
" gz= If specified, the heap dump is written in gzipped format using the given compression level.");
System.err.println(
" 1 (recommended) is the fastest, 9 the strongest compression.");
System.err.println(
"");
System.err.println(
" Example: jmap -dump:live,format=b,file=heap.bin ");
System.err.println(
"");
System.err.println(
" histo-options:");
System.err.println(
" live count only live objects (takes precedence if both \"live\
" and \"all\
" are specified)");
System.err.println(
" all count all objects in the heap (default if one of \"live\
" or \"all\
" is not specified)");
System.err.println(
" file= dump data to ");
System.err.println(
" parallel= Number of parallel threads to use for heap inspection:");
System.err.println(
" 0 (the default) means let the VM determine the number of threads to use");
System.err.println(
" 1 means use one thread (disable parallelism).");
System.err.println(
" For any other value the VM will try to use the specified number of threads, but might use fewer.");
System.err.println(
"");
System.err.println(
" Example: jmap -histo:live,file=/tmp/histo.data ");
System.exit(exit);
}
}
