| /* |
| * Copyright (c) 2005, 2006, 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 com.sun.tools.attach; |
| |
| import com.sun.tools.attach.spi.AttachProvider; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Properties; |
| import java.io.IOException; |
| |
| |
| /** |
| * A Java virtual machine. |
| * |
| * <p> A <code>VirtualMachine</code> represents a Java virtual machine to which this |
| * Java virtual machine has attached. The Java virtual machine to which it is |
| * attached is sometimes called the <i>target virtual machine</i>, or <i>target VM</i>. |
| * An application (typically a tool such as a managemet console or profiler) uses a |
| * VirtualMachine to load an agent into the target VM. For example, a profiler tool |
| * written in the Java Language might attach to a running application and load its |
| * profiler agent to profile the running application. </p> |
| * |
| * <p> A VirtualMachine is obtained by invoking the {@link #attach(String) attach} method |
| * with an identifier that identifies the target virtual machine. The identifier is |
| * implementation-dependent but is typically the process identifier (or pid) in |
| * environments where each Java virtual machine runs in its own operating system process. |
| * Alternatively, a <code>VirtualMachine</code> instance is obtained by invoking the |
| * {@link #attach(VirtualMachineDescriptor) attach} method with a {@link |
| * com.sun.tools.attach.VirtualMachineDescriptor VirtualMachineDescriptor} obtained |
| * from the list of virtual machine descriptors returned by the {@link #list list} method. |
| * Once a reference to a virtual machine is obtained, the {@link #loadAgent loadAgent}, |
| * {@link #loadAgentLibrary loadAgentLibrary}, and {@link #loadAgentPath loadAgentPath} |
| * methods are used to load agents into target virtual machine. The {@link |
| * #loadAgent loadAgent} method is used to load agents that are written in the Java |
| * Language and deployed in a {@link java.util.jar.JarFile JAR file}. (See |
| * {@link java.lang.instrument} for a detailed description on how these agents |
| * are loaded and started). The {@link #loadAgentLibrary loadAgentLibrary} and |
| * {@link #loadAgentPath loadAgentPath} methods are used to load agents that |
| * are deployed in a dynamic library and make use of the <a |
| * href="../../../../../../../../technotes/guides/jvmti/index.html">JVM Tools |
| * Interface</a>. </p> |
| * |
| * <p> In addition to loading agents a VirtualMachine provides read access to the |
| * {@link java.lang.System#getProperties() system properties} in the target VM. |
| * This can be useful in some environments where properties such as |
| * <code>java.home</code>, <code>os.name</code>, or <code>os.arch</code> are |
| * used to construct the path to agent that will be loaded into the target VM. |
| * |
| * <p> The following example demonstrates how VirtualMachine may be used:</p> |
| * |
| * <pre> |
| * |
| * // attach to target VM |
| * VirtualMachine vm = VirtualMachine.attach("2177"); |
| * |
| * // get system properties in target VM |
| * Properties props = vm.getSystemProperties(); |
| * |
| * // construct path to management agent |
| * String home = props.getProperty("java.home"); |
| * String agent = home + File.separator + "lib" + File.separator |
| * + "management-agent.jar"; |
| * |
| * // load agent into target VM |
| * vm.loadAgent(agent, "com.sun.management.jmxremote.port=5000"); |
| * |
| * // detach |
| * vm.detach(); |
| * |
| * </pre> |
| * |
| * <p> In this example we attach to a Java virtual machine that is identified by |
| * the process identifier <code>2177</code>. The system properties from the target |
| * VM are then used to construct the path to a <i>management agent</i> which is then |
| * loaded into the target VM. Once loaded the client detaches from the target VM. </p> |
| * |
| * <p> A VirtualMachine is safe for use by multiple concurrent threads. </p> |
| * |
| * @since 1.6 |
| */ |
| |
| public abstract class VirtualMachine { |
| private AttachProvider provider; |
| private String id; |
| private volatile int hash; // 0 => not computed |
| |
| /** |
| * Initializes a new instance of this class. |
| * |
| * @param provider |
| * The attach provider creating this class. |
| * @param id |
| * The abstract identifier that identifies the Java virtual machine. |
| * |
| * @throws NullPointerException |
| * If <code>provider</code> or <code>id</code> is <code>null</code>. |
| */ |
| protected VirtualMachine(AttachProvider provider, String id) { |
| if (provider == null) { |
| throw new NullPointerException("provider cannot be null"); |
| } |
| if (id == null) { |
| throw new NullPointerException("id cannot be null"); |
| } |
| this.provider = provider; |
| this.id = id; |
| } |
| |
| /** |
| * Return a list of Java virtual machines. |
| * |
| * <p> This method returns a list of Java {@link |
| * com.sun.tools.attach.VirtualMachineDescriptor} elements. |
| * The list is an aggregation of the virtual machine |
| * descriptor lists obtained by invoking the {@link |
| * com.sun.tools.attach.spi.AttachProvider#listVirtualMachines |
| * listVirtualMachines} method of all installed |
| * {@link com.sun.tools.attach.spi.AttachProvider attach providers}. |
| * If there are no Java virtual machines known to any provider |
| * then an empty list is returned. |
| * |
| * @return The list of virtual machine descriptors. |
| */ |
| public static List<VirtualMachineDescriptor> list() { |
| ArrayList<VirtualMachineDescriptor> l = |
| new ArrayList<VirtualMachineDescriptor>(); |
| List<AttachProvider> providers = AttachProvider.providers(); |
| for (AttachProvider provider: providers) { |
| l.addAll(provider.listVirtualMachines()); |
| } |
| return l; |
| } |
| |
| /** |
| * Attaches to a Java virtual machine. |
| * |
| * <p> This method obtains the list of attach providers by invoking the |
| * {@link com.sun.tools.attach.spi.AttachProvider#providers() |
| * AttachProvider.providers()} method. It then iterates overs the list |
| * and invokes each provider's {@link |
| * com.sun.tools.attach.spi.AttachProvider#attachVirtualMachine(java.lang.String) |
| * attachVirtualMachine} method in turn. If a provider successfully |
| * attaches then the iteration terminates, and the VirtualMachine created |
| * by the provider that successfully attached is returned by this method. |
| * If the <code>attachVirtualMachine</code> method of all providers throws |
| * {@link com.sun.tools.attach.AttachNotSupportedException AttachNotSupportedException} |
| * then this method also throws <code>AttachNotSupportedException</code>. |
| * This means that <code>AttachNotSupportedException</code> is thrown when |
| * the identifier provided to this method is invalid, or the identifier |
| * corresponds to a Java virtual machine that does not exist, or none |
| * of the providers can attach to it. This exception is also thrown if |
| * {@link com.sun.tools.attach.spi.AttachProvider#providers() |
| * AttachProvider.providers()} returns an empty list. </p> |
| * |
| * @param id |
| * The abstract identifier that identifies the Java virtual machine. |
| * |
| * @return A VirtualMachine representing the target VM. |
| * |
| * @throws SecurityException |
| * If a security manager has been installed and it denies |
| * {@link com.sun.tools.attach.AttachPermission AttachPermission} |
| * <tt>("attachVirtualMachine")</tt>, or another permission |
| * required by the implementation. |
| * |
| * @throws AttachNotSupportedException |
| * If the <code>attachVirtualmachine</code> method of all installed |
| * providers throws <code>AttachNotSupportedException</code>, or |
| * there aren't any providers installed. |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| * |
| * @throws NullPointerException |
| * If <code>id</code> is <code>null</code>. |
| */ |
| public static VirtualMachine attach(String id) |
| throws AttachNotSupportedException, IOException |
| { |
| if (id == null) { |
| throw new NullPointerException("id cannot be null"); |
| } |
| List<AttachProvider> providers = AttachProvider.providers(); |
| if (providers.size() == 0) { |
| throw new AttachNotSupportedException("no providers installed"); |
| } |
| AttachNotSupportedException lastExc = null; |
| for (AttachProvider provider: providers) { |
| try { |
| return provider.attachVirtualMachine(id); |
| } catch (AttachNotSupportedException x) { |
| lastExc = x; |
| } |
| } |
| throw lastExc; |
| } |
| |
| /** |
| * Attaches to a Java virtual machine. |
| * |
| * <p> This method first invokes the {@link |
| * com.sun.tools.attach.VirtualMachineDescriptor#provider() provider()} method |
| * of the given virtual machine descriptor to obtain the attach provider. It |
| * then invokes the attach provider's {@link |
| * com.sun.tools.attach.spi.AttachProvider#attachVirtualMachine(VirtualMachineDescriptor) |
| * attachVirtualMachine} to attach to the target VM. |
| * |
| * @param vmd |
| * The virtual machine descriptor. |
| * |
| * @return A VirtualMachine representing the target VM. |
| * |
| * @throws SecurityException |
| * If a security manager has been installed and it denies |
| * {@link com.sun.tools.attach.AttachPermission AttachPermission} |
| * <tt>("attachVirtualMachine")</tt>, or another permission |
| * required by the implementation. |
| * |
| * @throws AttachNotSupportedException |
| * If the attach provider's <code>attachVirtualmachine</code> |
| * throws <code>AttachNotSupportedException</code>. |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| * |
| * @throws NullPointerException |
| * If <code>vmd</code> is <code>null</code>. |
| */ |
| public static VirtualMachine attach(VirtualMachineDescriptor vmd) |
| throws AttachNotSupportedException, IOException |
| { |
| return vmd.provider().attachVirtualMachine(vmd); |
| } |
| |
| /** |
| * Detach from the virtual machine. |
| * |
| * <p> After detaching from the virtual machine, any further attempt to invoke |
| * operations on that virtual machine will cause an {@link java.io.IOException |
| * IOException} to be thrown. If an operation (such as {@link #loadAgent |
| * loadAgent} for example) is in progress when this method is invoked then |
| * the behaviour is implementation dependent. In other words, it is |
| * implementation specific if the operation completes or throws |
| * <tt>IOException</tt>. |
| * |
| * <p> If already detached from the virtual machine then invoking this |
| * method has no effect. </p> |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| */ |
| public abstract void detach() throws IOException; |
| |
| /** |
| * Returns the provider that created this virtual machine. |
| * |
| * @return The provider that created this virtual machine. |
| */ |
| public final AttachProvider provider() { |
| return provider; |
| } |
| |
| /** |
| * Returns the identifier for this Java virtual machine. |
| * |
| * @return The identifier for this Java virtual machine. |
| */ |
| public final String id() { |
| return id; |
| } |
| |
| /** |
| * Loads an agent library. |
| * |
| * <p> A <a href="../../../../../../../../technotes/guides/jvmti/index.html">JVM |
| * TI</a> client is called an <i>agent</i>. It is developed in a native language. |
| * A JVM TI agent is deployed in a platform specific manner but it is typically the |
| * platform equivalent of a dynamic library. This method causes the given agent |
| * library to be loaded into the target VM (if not already loaded). |
| * It then causes the target VM to invoke the <code>Agent_OnAttach</code> function |
| * as specified in the |
| * <a href="../../../../../../../../technotes/guides/jvmti/index.html"> JVM Tools |
| * Interface</a> specification. Note that the <code>Agent_OnAttach</code> |
| * function is invoked even if the agent library was loaded prior to invoking |
| * this method. |
| * |
| * <p> The agent library provided is the name of the agent library. It is interpreted |
| * in the target virtual machine in an implementation-dependent manner. Typically an |
| * implementation will expand the library name into an operating system specific file |
| * name. For example, on UNIX systems, the name <tt>foo</tt> might be expanded to |
| * <tt>libfoo.so</tt>, and located using the search path specified by the |
| * <tt>LD_LIBRARY_PATH</tt> environment variable.</p> |
| * |
| * <p> If the <code>Agent_OnAttach</code> function in the agent library returns |
| * an error then an {@link com.sun.tools.attach.AgentInitializationException} is |
| * thrown. The return value from the <code>Agent_OnAttach</code> can then be |
| * obtained by invoking the {@link |
| * com.sun.tools.attach.AgentInitializationException#returnValue() returnValue} |
| * method on the exception. </p> |
| * |
| * @param agentLibrary |
| * The name of the agent library. |
| * |
| * @param options |
| * The options to provide to the <code>Agent_OnAttach</code> |
| * function (can be <code>null</code>). |
| * |
| * @throws AgentLoadException |
| * If the agent library does not exist, or cannot be loaded for |
| * another reason. |
| * |
| * @throws AgentInitializationException |
| * If the <code>Agent_OnAttach</code> function returns an error |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| * |
| * @throws NullPointerException |
| * If <code>agentLibrary</code> is <code>null</code>. |
| * |
| * @see com.sun.tools.attach.AgentInitializationException#returnValue() |
| */ |
| public abstract void loadAgentLibrary(String agentLibrary, String options) |
| throws AgentLoadException, AgentInitializationException, IOException; |
| |
| /** |
| * Loads an agent library. |
| * |
| * <p> This convenience method works as if by invoking: |
| * |
| * <blockquote><tt> |
| * {@link #loadAgentLibrary(String, String) loadAgentLibrary}(agentLibrary, null); |
| * </tt></blockquote> |
| * |
| * @param agentLibrary |
| * The name of the agent library. |
| * |
| * @throws AgentLoadException |
| * If the agent library does not exist, or cannot be loaded for |
| * another reason. |
| * |
| * @throws AgentInitializationException |
| * If the <code>Agent_OnAttach</code> function returns an error |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| * |
| * @throws NullPointerException |
| * If <code>agentLibrary</code> is <code>null</code>. |
| */ |
| public void loadAgentLibrary(String agentLibrary) |
| throws AgentLoadException, AgentInitializationException, IOException |
| { |
| loadAgentLibrary(agentLibrary, null); |
| } |
| |
| /** |
| * Load a native agent library by full pathname. |
| * |
| * <p> A <a href="../../../../../../../../technotes/guides/jvmti/index.html">JVM |
| * TI</a> client is called an <i>agent</i>. It is developed in a native language. |
| * A JVM TI agent is deployed in a platform specific manner but it is typically the |
| * platform equivalent of a dynamic library. This method causes the given agent |
| * library to be loaded into the target VM (if not already loaded). |
| * It then causes the target VM to invoke the <code>Agent_OnAttach</code> function |
| * as specified in the |
| * <a href="../../../../../../../../technotes/guides/jvmti/index.html"> JVM Tools |
| * Interface</a> specification. Note that the <code>Agent_OnAttach</code> |
| * function is invoked even if the agent library was loaded prior to invoking |
| * this method. |
| * |
| * <p> The agent library provided is the absolute path from which to load the |
| * agent library. Unlike {@link #loadAgentLibrary loadAgentLibrary}, the library name |
| * is not expanded in the target virtual machine. </p> |
| * |
| * <p> If the <code>Agent_OnAttach</code> function in the agent library returns |
| * an error then an {@link com.sun.tools.attach.AgentInitializationException} is |
| * thrown. The return value from the <code>Agent_OnAttach</code> can then be |
| * obtained by invoking the {@link |
| * com.sun.tools.attach.AgentInitializationException#returnValue() returnValue} |
| * method on the exception. </p> |
| * |
| * @param agentPath |
| * The full path of the agent library. |
| * |
| * @param options |
| * The options to provide to the <code>Agent_OnAttach</code> |
| * function (can be <code>null</code>). |
| * |
| * @throws AgentLoadException |
| * If the agent library does not exist, or cannot be loaded for |
| * another reason. |
| * |
| * @throws AgentInitializationException |
| * If the <code>Agent_OnAttach</code> function returns an error |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| * |
| * @throws NullPointerException |
| * If <code>agentPath</code> is <code>null</code>. |
| * |
| * @see com.sun.tools.attach.AgentInitializationException#returnValue() |
| */ |
| public abstract void loadAgentPath(String agentPath, String options) |
| throws AgentLoadException, AgentInitializationException, IOException; |
| |
| /** |
| * Load a native agent library by full pathname. |
| * |
| * <p> This convenience method works as if by invoking: |
| * |
| * <blockquote><tt> |
| * {@link #loadAgentPath(String, String) loadAgentPath}(agentLibrary, null); |
| * </tt></blockquote> |
| * |
| * @param agentPath |
| * The full path to the agent library. |
| * |
| * @throws AgentLoadException |
| * If the agent library does not exist, or cannot be loaded for |
| * another reason. |
| * |
| * @throws AgentInitializationException |
| * If the <code>Agent_OnAttach</code> function returns an error |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| * |
| * @throws NullPointerException |
| * If <code>agentPath</code> is <code>null</code>. |
| */ |
| public void loadAgentPath(String agentPath) |
| throws AgentLoadException, AgentInitializationException, IOException |
| { |
| loadAgentPath(agentPath, null); |
| } |
| |
| |
| /** |
| * Loads an agent. |
| * |
| * <p> The agent provided to this method is a path name to a JAR file on the file |
| * system of the target virtual machine. This path is passed to the target virtual |
| * machine where it is interpreted. The target virtual machine attempts to start |
| * the agent as specified by the {@link java.lang.instrument} specification. |
| * That is, the specified JAR file is added to the system class path (of the target |
| * virtual machine), and the <code>agentmain</code> method of the agent class, specified |
| * by the <code>Agent-Class</code> attribute in the JAR manifest, is invoked. This |
| * method completes when the <code>agentmain</code> method completes. |
| * |
| * @param agent |
| * Path to the JAR file containing the agent. |
| * |
| * @param options |
| * The options to provide to the agent's <code>agentmain</code> |
| * method (can be <code>null</code>). |
| * |
| * @throws AgentLoadException |
| * If the agent does not exist, or cannot be started in the manner |
| * specified in the {@link java.lang.instrument} specification. |
| * |
| * @throws AgentInitializationException |
| * If the <code>agentmain</code> throws an exception |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| * |
| * @throws NullPointerException |
| * If <code>agent</code> is <code>null</code>. |
| */ |
| public abstract void loadAgent(String agent, String options) |
| throws AgentLoadException, AgentInitializationException, IOException; |
| |
| /** |
| * Loads an agent. |
| * |
| * <p> This convenience method works as if by invoking: |
| * |
| * <blockquote><tt> |
| * {@link #loadAgent(String, String) loadAgent}(agent, null); |
| * </tt></blockquote> |
| * |
| * @param agent |
| * Path to the JAR file containing the agent. |
| * |
| * @throws AgentLoadException |
| * If the agent does not exist, or cannot be started in the manner |
| * specified in the {@link java.lang.instrument} specification. |
| * |
| * @throws AgentInitializationException |
| * If the <code>agentmain</code> throws an exception |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| * |
| * @throws NullPointerException |
| * If <code>agent</code> is <code>null</code>. |
| */ |
| public void loadAgent(String agent) |
| throws AgentLoadException, AgentInitializationException, IOException |
| { |
| loadAgent(agent, null); |
| } |
| |
| /** |
| * Returns the current system properties in the target virtual machine. |
| * |
| * <p> This method returns the system properties in the target virtual |
| * machine. Properties whose key or value is not a <tt>String</tt> are |
| * omitted. The method is approximately equivalent to the invocation of the |
| * method {@link java.lang.System#getProperties System.getProperties} |
| * in the target virtual machine except that properties with a key or |
| * value that is not a <tt>String</tt> are not included. |
| * |
| * <p> This method is typically used to decide which agent to load into |
| * the target virtual machine with {@link #loadAgent loadAgent}, or |
| * {@link #loadAgentLibrary loadAgentLibrary}. For example, the |
| * <code>java.home</code> or <code>user.dir</code> properties might be |
| * use to create the path to the agent library or JAR file. |
| * |
| * @return The system properties |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| * |
| * @see java.lang.System#getProperties |
| * @see #loadAgentLibrary |
| * @see #loadAgent |
| */ |
| public abstract Properties getSystemProperties() throws IOException; |
| |
| /** |
| * Returns the current <i>agent properties</i> in the target virtual |
| * machine. |
| * |
| * <p> The target virtual machine can maintain a list of properties on |
| * behalf of agents. The manner in which this is done, the names of the |
| * properties, and the types of values that are allowed, is implementation |
| * specific. Agent properties are typically used to store communication |
| * end-points and other agent configuration details. For example, a debugger |
| * agent might create an agent property for its transport address. |
| * |
| * <p> This method returns the agent properties whose key and value is a |
| * <tt>String</tt>. Properties whose key or value is not a <tt>String</tt> |
| * are omitted. If there are no agent properties maintained in the target |
| * virtual machine then an empty property list is returned. |
| * |
| * @return The agent properties |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| */ |
| public abstract Properties getAgentProperties() throws IOException; |
| |
| /** |
| * Returns a hash-code value for this VirtualMachine. The hash |
| * code is based upon the VirtualMachine's components, and satifies |
| * the general contract of the {@link java.lang.Object#hashCode() |
| * Object.hashCode} method. |
| * |
| * @return A hash-code value for this virtual machine |
| */ |
| public int hashCode() { |
| if (hash != 0) { |
| return hash; |
| } |
| hash = provider.hashCode() * 127 + id.hashCode(); |
| return hash; |
| } |
| |
| /** |
| * Tests this VirtualMachine for equality with another object. |
| * |
| * <p> If the given object is not a VirtualMachine then this |
| * method returns <tt>false</tt>. For two VirtualMachines to |
| * be considered equal requires that they both reference the same |
| * provider, and their {@link VirtualMachineDescriptor#id() identifiers} are equal. </p> |
| * |
| * <p> This method satisfies the general contract of the {@link |
| * java.lang.Object#equals(Object) Object.equals} method. </p> |
| * |
| * @param ob The object to which this object is to be compared |
| * |
| * @return <tt>true</tt> if, and only if, the given object is |
| * a VirtualMachine that is equal to this |
| * VirtualMachine. |
| */ |
| public boolean equals(Object ob) { |
| if (ob == this) |
| return true; |
| if (!(ob instanceof VirtualMachine)) |
| return false; |
| VirtualMachine other = (VirtualMachine)ob; |
| if (other.provider() != this.provider()) { |
| return false; |
| } |
| if (!other.id().equals(this.id())) { |
| return false; |
| } |
| return true; |
| } |
| |
| /** |
| * Returns the string representation of the <code>VirtualMachine</code>. |
| */ |
| public String toString() { |
| return provider.toString() + ": " + id; |
| } |
| } |
