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* 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package sun.tools.jmap;
import java.lang.reflect.Method;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import com.sun.tools.attach.VirtualMachine;
import com.sun.tools.attach.AttachNotSupportedException;
import sun.tools.attach.HotSpotVirtualMachine;
/*
* 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 {
// Options handled by the attach mechanism
private static String HISTO_OPTION = "-histo";
private static String LIVE_HISTO_OPTION = "-histo:live";
private static String DUMP_OPTION_PREFIX = "-dump:";
// These options imply the use of a SA tool
private static String SA_TOOL_OPTIONS =
"-heap|-heap:format=b|-clstats|-finalizerinfo";
// The -F (force) option is currently not passed through to SA
private static String FORCE_SA_OPTION = "-F";
// Default option (if nothing provided)
private static String DEFAULT_OPTION = "-pmap";
public static void main(String[] args) throws Exception {
if (args.length == 0) {
usage(1); // no arguments
}
// used to indicate if we should use SA
boolean useSA = false;
// the chosen option (-heap, -dump:*, ... )
String option = null;
// First iterate over the options (arguments starting with -). There should be
// one (but maybe two if -F is also used).
int optionCount = 0;
while (optionCount < args.length) {
String arg = args[optionCount];
if (!arg.startsWith("-")) {
break;
}
if (arg.equals("-help") || arg.equals("-h")) {
usage(0);
} else if (arg.equals(FORCE_SA_OPTION)) {
useSA = true;
} else {
if (option != null) {
usage(1); // option already specified
}
option = arg;
}
optionCount++;
}
// if no option provided then use default.
if (option == null) {
option = DEFAULT_OPTION;
}
if (option.matches(SA_TOOL_OPTIONS)) {
useSA = true;
}
// Next we check the parameter count. For the SA tools there are
// one or two parameters. For the built-in -dump option there is
// only one parameter (the process-id)
int paramCount = args.length - optionCount;
if (paramCount == 0 || paramCount > 2) {
usage(1);
}
if (optionCount == 0 || paramCount != 1) {
useSA = true;
} else {
// the parameter for the -dump option is a process-id.
// If it doesn't parse to a number then it must be SA
// debug server
if (!args[optionCount].matches("[0-9]+")) {
useSA = true;
}
}
// at this point we know if we are executing an SA tool or a built-in
// option.
if (useSA) {
// parameters (<pid> or <exe> <core>)
String params[] = new String[paramCount];
for (int i=optionCount; i<args.length; i++ ){
params[i-optionCount] = args[i];
}
runTool(option, params);
} else {
String pid = 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
if (option.equals(HISTO_OPTION)) {
histo(pid, false);
} else if (option.equals(LIVE_HISTO_OPTION)) {
histo(pid, true);
} else if (option.startsWith(DUMP_OPTION_PREFIX)) {
dump(pid, option);
} else {
usage(1);
}
}
}
// Invoke SA tool with the given arguments
private static void runTool(String option, String args[]) throws Exception {
String[][] tools = {
{ "-pmap", "sun.jvm.hotspot.tools.PMap" },
{ "-heap", "sun.jvm.hotspot.tools.HeapSummary" },
{ "-heap:format=b", "sun.jvm.hotspot.tools.HeapDumper" },
{ "-histo", "sun.jvm.hotspot.tools.ObjectHistogram" },
{ "-clstats", "sun.jvm.hotspot.tools.ClassLoaderStats" },
{ "-finalizerinfo", "sun.jvm.hotspot.tools.FinalizerInfo" },
};
String tool = null;
// -dump option needs to be handled in a special way
if (option.startsWith(DUMP_OPTION_PREFIX)) {
// first check that the option can be parsed
String fn = parseDumpOptions(option);
if (fn == null) {
usage(1);
}
// tool for heap dumping
tool = "sun.jvm.hotspot.tools.HeapDumper";
// HeapDumper -f <file>
args = prepend(fn, args);
args = prepend("-f", args);
} else {
int i=0;
while (i < tools.length) {
if (option.equals(tools[i][0])) {
tool = tools[i][1];
break;
}
i++;
}
}
if (tool == null) {
usage(1); // no mapping to tool
}
// Tool not available on this platform.
Class<?> c = loadClass(tool);
if (c == null) {
usage(1);
}
// invoke the main method with the arguments
Class[] argTypes = { String[].class } ;
Method m = c.getDeclaredMethod("main", argTypes);
Object[] invokeArgs = { args };
m.invoke(null, invokeArgs);
}
// loads the given class using the system class loader
private static Class<?> loadClass(String name) {
//
// We specify the system clas loader so as to cater for development
// environments where this class is on the boot class path but sa-jdi.jar
// is on the system class path. Once the JDK is deployed then both
// tools.jar and sa-jdi.jar are on the system class path.
//
try {
return Class.forName(name, true,
ClassLoader.getSystemClassLoader());
} catch (Exception x) { }
return null;
}
private static final String LIVE_OBJECTS_OPTION = "-live";
private static final String ALL_OBJECTS_OPTION = "-all";
private static void histo(String pid, boolean live) throws IOException {
VirtualMachine vm = attach(pid);
InputStream in = ((HotSpotVirtualMachine)vm).
heapHisto(live ? LIVE_OBJECTS_OPTION : ALL_OBJECTS_OPTION);
drain(vm, in);
}
private static void dump(String pid, String options) throws IOException {
// parse the options to get the dump filename
String filename = parseDumpOptions(options);
if (filename == null) {
usage(1); // invalid options or no filename
}
// 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.
filename = new File(filename).getCanonicalPath();
// dump live objects only or not
boolean live = isDumpLiveObjects(options);
VirtualMachine vm = attach(pid);
System.out.println("Dumping heap to " + filename + " ...");
InputStream in = ((HotSpotVirtualMachine)vm).
dumpHeap((Object)filename,
(live ? LIVE_OBJECTS_OPTION : ALL_OBJECTS_OPTION));
drain(vm, in);
}
// Parse the options to the -dump option. Valid options are format=b and
// file=<file>. Returns <file> if provided. Returns null if <file> not
// provided, or invalid option.
private static String parseDumpOptions(String arg) {
assert arg.startsWith(DUMP_OPTION_PREFIX);
String filename = null;
// options are separated by comma (,)
String options[] = arg.substring(DUMP_OPTION_PREFIX.length()).split(",");
for (int i=0; i<options.length; i++) {
String option = options[i];
if (option.equals("format=b")) {
// ignore format (not needed at this time)
} else if (option.equals("live")) {
// a valid suboption
} else {
// file=<file> - check that <file> is specified
if (option.startsWith("file=")) {
filename = option.substring(5);
if (filename.length() == 0) {
return null;
}
} else {
return null; // option not recognized
}
}
}
return filename;
}
private static boolean isDumpLiveObjects(String arg) {
// options are separated by comma (,)
String options[] = arg.substring(DUMP_OPTION_PREFIX.length()).split(",");
for (String suboption : options) {
if (suboption.equals("live")) {
return true;
}
}
return false;
}
// Attach to <pid>, existing if we fail to attach
private static VirtualMachine attach(String pid) {
try {
return VirtualMachine.attach(pid);
} catch (Exception x) {
String msg = x.getMessage();
if (msg != null) {
System.err.println(pid + ": " + msg);
} else {
x.printStackTrace();
}
if ((x instanceof AttachNotSupportedException) && haveSA()) {
System.err.println("The -F option can be used when the " +
"target process is not responding");
}
System.exit(1);
return null; // keep compiler happy
}
}
// Read the stream from the target VM until EOF, then detach
private static void drain(VirtualMachine vm, InputStream in) throws IOException {
// 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);
in.close();
vm.detach();
}
// return a new string array with arg as the first element
private static String[] prepend(String arg, String args[]) {
String[] newargs = new String[args.length+1];
newargs[0] = arg;
System.arraycopy(args, 0, newargs, 1, args.length);
return newargs;
}
// returns true if SA is available
private static boolean haveSA() {
Class<?> c = loadClass("sun.jvm.hotspot.tools.HeapSummary");
return (c != null);
}
// print usage message
private static void usage(int exit) {
System.err.println("Usage:");
if (haveSA()) {
System.err.println(" jmap [option] <pid>");
System.err.println(" (to connect to running process)");
System.err.println(" jmap [option] <executable <core>");
System.err.println(" (to connect to a core file)");
System.err.println(" jmap [option] [server_id@]<remote server IP or hostname>");
System.err.println(" (to connect to remote debug server)");
System.err.println("");
System.err.println("where <option> is one of:");
System.err.println(" <none> to print same info as Solaris pmap");
System.err.println(" -heap to print java heap summary");
System.err.println(" -histo[:live] to print histogram of java object heap; if the \"live\"");
System.err.println(" suboption is specified, only count live objects");
System.err.println(" -clstats to print class loader statistics");
System.err.println(" -finalizerinfo to print information on objects awaiting finalization");
System.err.println(" -dump:<dump-options> to dump java heap in hprof binary format");
System.err.println(" dump-options:");
System.err.println(" live dump only live objects; if not specified,");
System.err.println(" all objects in the heap are dumped.");
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