--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/lang/Runtime.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,897 @@
+/*
+ * Copyright 1995-2006 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.lang;
+
+import java.io.*;
+import java.util.StringTokenizer;
+
+/**
+ * Every Java application has a single instance of class
+ * <code>Runtime</code> that allows the application to interface with
+ * the environment in which the application is running. The current
+ * runtime can be obtained from the <code>getRuntime</code> method.
+ * <p>
+ * An application cannot create its own instance of this class.
+ *
+ * @author unascribed
+ * @see java.lang.Runtime#getRuntime()
+ * @since JDK1.0
+ */
+
+public class Runtime {
+ private static Runtime currentRuntime = new Runtime();
+
+ /**
+ * Returns the runtime object associated with the current Java application.
+ * Most of the methods of class <code>Runtime</code> are instance
+ * methods and must be invoked with respect to the current runtime object.
+ *
+ * @return the <code>Runtime</code> object associated with the current
+ * Java application.
+ */
+ public static Runtime getRuntime() {
+ return currentRuntime;
+ }
+
+ /** Don't let anyone else instantiate this class */
+ private Runtime() {}
+
+ /**
+ * Terminates the currently running Java virtual machine by initiating its
+ * shutdown sequence. This method never returns normally. The argument
+ * serves as a status code; by convention, a nonzero status code indicates
+ * abnormal termination.
+ *
+ * <p> The virtual machine's shutdown sequence consists of two phases. In
+ * the first phase all registered {@link #addShutdownHook shutdown hooks},
+ * if any, are started in some unspecified order and allowed to run
+ * concurrently until they finish. In the second phase all uninvoked
+ * finalizers are run if {@link #runFinalizersOnExit finalization-on-exit}
+ * has been enabled. Once this is done the virtual machine {@link #halt
+ * halts}.
+ *
+ * <p> If this method is invoked after the virtual machine has begun its
+ * shutdown sequence then if shutdown hooks are being run this method will
+ * block indefinitely. If shutdown hooks have already been run and on-exit
+ * finalization has been enabled then this method halts the virtual machine
+ * with the given status code if the status is nonzero; otherwise, it
+ * blocks indefinitely.
+ *
+ * <p> The <tt>{@link System#exit(int) System.exit}</tt> method is the
+ * conventional and convenient means of invoking this method. <p>
+ *
+ * @param status
+ * Termination status. By convention, a nonzero status code
+ * indicates abnormal termination.
+ *
+ * @throws SecurityException
+ * If a security manager is present and its <tt>{@link
+ * SecurityManager#checkExit checkExit}</tt> method does not permit
+ * exiting with the specified status
+ *
+ * @see java.lang.SecurityException
+ * @see java.lang.SecurityManager#checkExit(int)
+ * @see #addShutdownHook
+ * @see #removeShutdownHook
+ * @see #runFinalizersOnExit
+ * @see #halt(int)
+ */
+ public void exit(int status) {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkExit(status);
+ }
+ Shutdown.exit(status);
+ }
+
+ /**
+ * Registers a new virtual-machine shutdown hook.
+ *
+ * <p> The Java virtual machine <i>shuts down</i> in response to two kinds
+ * of events:
+ *
+ * <ul>
+ *
+ * <p> <li> The program <i>exits</i> normally, when the last non-daemon
+ * thread exits or when the <tt>{@link #exit exit}</tt> (equivalently,
+ * <tt>{@link System#exit(int) System.exit}</tt>) method is invoked, or
+ *
+ * <p> <li> The virtual machine is <i>terminated</i> in response to a
+ * user interrupt, such as typing <tt>^C</tt>, or a system-wide event,
+ * such as user logoff or system shutdown.
+ *
+ * </ul>
+ *
+ * <p> A <i>shutdown hook</i> is simply an initialized but unstarted
+ * thread. When the virtual machine begins its shutdown sequence it will
+ * start all registered shutdown hooks in some unspecified order and let
+ * them run concurrently. When all the hooks have finished it will then
+ * run all uninvoked finalizers if finalization-on-exit has been enabled.
+ * Finally, the virtual machine will halt. Note that daemon threads will
+ * continue to run during the shutdown sequence, as will non-daemon threads
+ * if shutdown was initiated by invoking the <tt>{@link #exit exit}</tt>
+ * method.
+ *
+ * <p> Once the shutdown sequence has begun it can be stopped only by
+ * invoking the <tt>{@link #halt halt}</tt> method, which forcibly
+ * terminates the virtual machine.
+ *
+ * <p> Once the shutdown sequence has begun it is impossible to register a
+ * new shutdown hook or de-register a previously-registered hook.
+ * Attempting either of these operations will cause an
+ * <tt>{@link IllegalStateException}</tt> to be thrown.
+ *
+ * <p> Shutdown hooks run at a delicate time in the life cycle of a virtual
+ * machine and should therefore be coded defensively. They should, in
+ * particular, be written to be thread-safe and to avoid deadlocks insofar
+ * as possible. They should also not rely blindly upon services that may
+ * have registered their own shutdown hooks and therefore may themselves in
+ * the process of shutting down. Attempts to use other thread-based
+ * services such as the AWT event-dispatch thread, for example, may lead to
+ * deadlocks.
+ *
+ * <p> Shutdown hooks should also finish their work quickly. When a
+ * program invokes <tt>{@link #exit exit}</tt> the expectation is
+ * that the virtual machine will promptly shut down and exit. When the
+ * virtual machine is terminated due to user logoff or system shutdown the
+ * underlying operating system may only allow a fixed amount of time in
+ * which to shut down and exit. It is therefore inadvisable to attempt any
+ * user interaction or to perform a long-running computation in a shutdown
+ * hook.
+ *
+ * <p> Uncaught exceptions are handled in shutdown hooks just as in any
+ * other thread, by invoking the <tt>{@link ThreadGroup#uncaughtException
+ * uncaughtException}</tt> method of the thread's <tt>{@link
+ * ThreadGroup}</tt> object. The default implementation of this method
+ * prints the exception's stack trace to <tt>{@link System#err}</tt> and
+ * terminates the thread; it does not cause the virtual machine to exit or
+ * halt.
+ *
+ * <p> In rare circumstances the virtual machine may <i>abort</i>, that is,
+ * stop running without shutting down cleanly. This occurs when the
+ * virtual machine is terminated externally, for example with the
+ * <tt>SIGKILL</tt> signal on Unix or the <tt>TerminateProcess</tt> call on
+ * Microsoft Windows. The virtual machine may also abort if a native
+ * method goes awry by, for example, corrupting internal data structures or
+ * attempting to access nonexistent memory. If the virtual machine aborts
+ * then no guarantee can be made about whether or not any shutdown hooks
+ * will be run. <p>
+ *
+ * @param hook
+ * An initialized but unstarted <tt>{@link Thread}</tt> object
+ *
+ * @throws IllegalArgumentException
+ * If the specified hook has already been registered,
+ * or if it can be determined that the hook is already running or
+ * has already been run
+ *
+ * @throws IllegalStateException
+ * If the virtual machine is already in the process
+ * of shutting down
+ *
+ * @throws SecurityException
+ * If a security manager is present and it denies
+ * <tt>{@link RuntimePermission}("shutdownHooks")</tt>
+ *
+ * @see #removeShutdownHook
+ * @see #halt(int)
+ * @see #exit(int)
+ * @since 1.3
+ */
+ public void addShutdownHook(Thread hook) {
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ sm.checkPermission(new RuntimePermission("shutdownHooks"));
+ }
+ ApplicationShutdownHooks.add(hook);
+ }
+
+ /**
+ * De-registers a previously-registered virtual-machine shutdown hook. <p>
+ *
+ * @param hook the hook to remove
+ * @return <tt>true</tt> if the specified hook had previously been
+ * registered and was successfully de-registered, <tt>false</tt>
+ * otherwise.
+ *
+ * @throws IllegalStateException
+ * If the virtual machine is already in the process of shutting
+ * down
+ *
+ * @throws SecurityException
+ * If a security manager is present and it denies
+ * <tt>{@link RuntimePermission}("shutdownHooks")</tt>
+ *
+ * @see #addShutdownHook
+ * @see #exit(int)
+ * @since 1.3
+ */
+ public boolean removeShutdownHook(Thread hook) {
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ sm.checkPermission(new RuntimePermission("shutdownHooks"));
+ }
+ return ApplicationShutdownHooks.remove(hook);
+ }
+
+ /**
+ * Forcibly terminates the currently running Java virtual machine. This
+ * method never returns normally.
+ *
+ * <p> This method should be used with extreme caution. Unlike the
+ * <tt>{@link #exit exit}</tt> method, this method does not cause shutdown
+ * hooks to be started and does not run uninvoked finalizers if
+ * finalization-on-exit has been enabled. If the shutdown sequence has
+ * already been initiated then this method does not wait for any running
+ * shutdown hooks or finalizers to finish their work. <p>
+ *
+ * @param status
+ * Termination status. By convention, a nonzero status code
+ * indicates abnormal termination. If the <tt>{@link Runtime#exit
+ * exit}</tt> (equivalently, <tt>{@link System#exit(int)
+ * System.exit}</tt>) method has already been invoked then this
+ * status code will override the status code passed to that method.
+ *
+ * @throws SecurityException
+ * If a security manager is present and its <tt>{@link
+ * SecurityManager#checkExit checkExit}</tt> method does not permit
+ * an exit with the specified status
+ *
+ * @see #exit
+ * @see #addShutdownHook
+ * @see #removeShutdownHook
+ * @since 1.3
+ */
+ public void halt(int status) {
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ sm.checkExit(status);
+ }
+ Shutdown.halt(status);
+ }
+
+ /**
+ * Enable or disable finalization on exit; doing so specifies that the
+ * finalizers of all objects that have finalizers that have not yet been
+ * automatically invoked are to be run before the Java runtime exits.
+ * By default, finalization on exit is disabled.
+ *
+ * <p>If there is a security manager,
+ * its <code>checkExit</code> method is first called
+ * with 0 as its argument to ensure the exit is allowed.
+ * This could result in a SecurityException.
+ *
+ * @param value true to enable finalization on exit, false to disable
+ * @deprecated This method is inherently unsafe. It may result in
+ * finalizers being called on live objects while other threads are
+ * concurrently manipulating those objects, resulting in erratic
+ * behavior or deadlock.
+ *
+ * @throws SecurityException
+ * if a security manager exists and its <code>checkExit</code>
+ * method doesn't allow the exit.
+ *
+ * @see java.lang.Runtime#exit(int)
+ * @see java.lang.Runtime#gc()
+ * @see java.lang.SecurityManager#checkExit(int)
+ * @since JDK1.1
+ */
+ @Deprecated
+ public static void runFinalizersOnExit(boolean value) {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ try {
+ security.checkExit(0);
+ } catch (SecurityException e) {
+ throw new SecurityException("runFinalizersOnExit");
+ }
+ }
+ Shutdown.setRunFinalizersOnExit(value);
+ }
+
+ /**
+ * Executes the specified string command in a separate process.
+ *
+ * <p>This is a convenience method. An invocation of the form
+ * <tt>exec(command)</tt>
+ * behaves in exactly the same way as the invocation
+ * <tt>{@link #exec(String, String[], File) exec}(command, null, null)</tt>.
+ *
+ * @param command a specified system command.
+ *
+ * @return A new {@link Process} object for managing the subprocess
+ *
+ * @throws SecurityException
+ * If a security manager exists and its
+ * {@link SecurityManager#checkExec checkExec}
+ * method doesn't allow creation of the subprocess
+ *
+ * @throws IOException
+ * If an I/O error occurs
+ *
+ * @throws NullPointerException
+ * If <code>command</code> is <code>null</code>
+ *
+ * @throws IllegalArgumentException
+ * If <code>command</code> is empty
+ *
+ * @see #exec(String[], String[], File)
+ * @see ProcessBuilder
+ */
+ public Process exec(String command) throws IOException {
+ return exec(command, null, null);
+ }
+
+ /**
+ * Executes the specified string command in a separate process with the
+ * specified environment.
+ *
+ * <p>This is a convenience method. An invocation of the form
+ * <tt>exec(command, envp)</tt>
+ * behaves in exactly the same way as the invocation
+ * <tt>{@link #exec(String, String[], File) exec}(command, envp, null)</tt>.
+ *
+ * @param command a specified system command.
+ *
+ * @param envp array of strings, each element of which
+ * has environment variable settings in the format
+ * <i>name</i>=<i>value</i>, or
+ * <tt>null</tt> if the subprocess should inherit
+ * the environment of the current process.
+ *
+ * @return A new {@link Process} object for managing the subprocess
+ *
+ * @throws SecurityException
+ * If a security manager exists and its
+ * {@link SecurityManager#checkExec checkExec}
+ * method doesn't allow creation of the subprocess
+ *
+ * @throws IOException
+ * If an I/O error occurs
+ *
+ * @throws NullPointerException
+ * If <code>command</code> is <code>null</code>,
+ * or one of the elements of <code>envp</code> is <code>null</code>
+ *
+ * @throws IllegalArgumentException
+ * If <code>command</code> is empty
+ *
+ * @see #exec(String[], String[], File)
+ * @see ProcessBuilder
+ */
+ public Process exec(String command, String[] envp) throws IOException {
+ return exec(command, envp, null);
+ }
+
+ /**
+ * Executes the specified string command in a separate process with the
+ * specified environment and working directory.
+ *
+ * <p>This is a convenience method. An invocation of the form
+ * <tt>exec(command, envp, dir)</tt>
+ * behaves in exactly the same way as the invocation
+ * <tt>{@link #exec(String[], String[], File) exec}(cmdarray, envp, dir)</tt>,
+ * where <code>cmdarray</code> is an array of all the tokens in
+ * <code>command</code>.
+ *
+ * <p>More precisely, the <code>command</code> string is broken
+ * into tokens using a {@link StringTokenizer} created by the call
+ * <code>new {@link StringTokenizer}(command)</code> with no
+ * further modification of the character categories. The tokens
+ * produced by the tokenizer are then placed in the new string
+ * array <code>cmdarray</code>, in the same order.
+ *
+ * @param command a specified system command.
+ *
+ * @param envp array of strings, each element of which
+ * has environment variable settings in the format
+ * <i>name</i>=<i>value</i>, or
+ * <tt>null</tt> if the subprocess should inherit
+ * the environment of the current process.
+ *
+ * @param dir the working directory of the subprocess, or
+ * <tt>null</tt> if the subprocess should inherit
+ * the working directory of the current process.
+ *
+ * @return A new {@link Process} object for managing the subprocess
+ *
+ * @throws SecurityException
+ * If a security manager exists and its
+ * {@link SecurityManager#checkExec checkExec}
+ * method doesn't allow creation of the subprocess
+ *
+ * @throws IOException
+ * If an I/O error occurs
+ *
+ * @throws NullPointerException
+ * If <code>command</code> is <code>null</code>,
+ * or one of the elements of <code>envp</code> is <code>null</code>
+ *
+ * @throws IllegalArgumentException
+ * If <code>command</code> is empty
+ *
+ * @see ProcessBuilder
+ * @since 1.3
+ */
+ public Process exec(String command, String[] envp, File dir)
+ throws IOException {
+ if (command.length() == 0)
+ throw new IllegalArgumentException("Empty command");
+
+ StringTokenizer st = new StringTokenizer(command);
+ String[] cmdarray = new String[st.countTokens()];
+ for (int i = 0; st.hasMoreTokens(); i++)
+ cmdarray[i] = st.nextToken();
+ return exec(cmdarray, envp, dir);
+ }
+
+ /**
+ * Executes the specified command and arguments in a separate process.
+ *
+ * <p>This is a convenience method. An invocation of the form
+ * <tt>exec(cmdarray)</tt>
+ * behaves in exactly the same way as the invocation
+ * <tt>{@link #exec(String[], String[], File) exec}(cmdarray, null, null)</tt>.
+ *
+ * @param cmdarray array containing the command to call and
+ * its arguments.
+ *
+ * @return A new {@link Process} object for managing the subprocess
+ *
+ * @throws SecurityException
+ * If a security manager exists and its
+ * {@link SecurityManager#checkExec checkExec}
+ * method doesn't allow creation of the subprocess
+ *
+ * @throws IOException
+ * If an I/O error occurs
+ *
+ * @throws NullPointerException
+ * If <code>cmdarray</code> is <code>null</code>,
+ * or one of the elements of <code>cmdarray</code> is <code>null</code>
+ *
+ * @throws IndexOutOfBoundsException
+ * If <code>cmdarray</code> is an empty array
+ * (has length <code>0</code>)
+ *
+ * @see ProcessBuilder
+ */
+ public Process exec(String cmdarray[]) throws IOException {
+ return exec(cmdarray, null, null);
+ }
+
+ /**
+ * Executes the specified command and arguments in a separate process
+ * with the specified environment.
+ *
+ * <p>This is a convenience method. An invocation of the form
+ * <tt>exec(cmdarray, envp)</tt>
+ * behaves in exactly the same way as the invocation
+ * <tt>{@link #exec(String[], String[], File) exec}(cmdarray, envp, null)</tt>.
+ *
+ * @param cmdarray array containing the command to call and
+ * its arguments.
+ *
+ * @param envp array of strings, each element of which
+ * has environment variable settings in the format
+ * <i>name</i>=<i>value</i>, or
+ * <tt>null</tt> if the subprocess should inherit
+ * the environment of the current process.
+ *
+ * @return A new {@link Process} object for managing the subprocess
+ *
+ * @throws SecurityException
+ * If a security manager exists and its
+ * {@link SecurityManager#checkExec checkExec}
+ * method doesn't allow creation of the subprocess
+ *
+ * @throws IOException
+ * If an I/O error occurs
+ *
+ * @throws NullPointerException
+ * If <code>cmdarray</code> is <code>null</code>,
+ * or one of the elements of <code>cmdarray</code> is <code>null</code>,
+ * or one of the elements of <code>envp</code> is <code>null</code>
+ *
+ * @throws IndexOutOfBoundsException
+ * If <code>cmdarray</code> is an empty array
+ * (has length <code>0</code>)
+ *
+ * @see ProcessBuilder
+ */
+ public Process exec(String[] cmdarray, String[] envp) throws IOException {
+ return exec(cmdarray, envp, null);
+ }
+
+
+ /**
+ * Executes the specified command and arguments in a separate process with
+ * the specified environment and working directory.
+ *
+ * <p>Given an array of strings <code>cmdarray</code>, representing the
+ * tokens of a command line, and an array of strings <code>envp</code>,
+ * representing "environment" variable settings, this method creates
+ * a new process in which to execute the specified command.
+ *
+ * <p>This method checks that <code>cmdarray</code> is a valid operating
+ * system command. Which commands are valid is system-dependent,
+ * but at the very least the command must be a non-empty list of
+ * non-null strings.
+ *
+ * <p>If <tt>envp</tt> is <tt>null</tt>, the subprocess inherits the
+ * environment settings of the current process.
+ *
+ * <p>{@link ProcessBuilder#start()} is now the preferred way to
+ * start a process with a modified environment.
+ *
+ * <p>The working directory of the new subprocess is specified by <tt>dir</tt>.
+ * If <tt>dir</tt> is <tt>null</tt>, the subprocess inherits the
+ * current working directory of the current process.
+ *
+ * <p>If a security manager exists, its
+ * {@link SecurityManager#checkExec checkExec}
+ * method is invoked with the first component of the array
+ * <code>cmdarray</code> as its argument. This may result in a
+ * {@link SecurityException} being thrown.
+ *
+ * <p>Starting an operating system process is highly system-dependent.
+ * Among the many things that can go wrong are:
+ * <ul>
+ * <li>The operating system program file was not found.
+ * <li>Access to the program file was denied.
+ * <li>The working directory does not exist.
+ * </ul>
+ *
+ * <p>In such cases an exception will be thrown. The exact nature
+ * of the exception is system-dependent, but it will always be a
+ * subclass of {@link IOException}.
+ *
+ *
+ * @param cmdarray array containing the command to call and
+ * its arguments.
+ *
+ * @param envp array of strings, each element of which
+ * has environment variable settings in the format
+ * <i>name</i>=<i>value</i>, or
+ * <tt>null</tt> if the subprocess should inherit
+ * the environment of the current process.
+ *
+ * @param dir the working directory of the subprocess, or
+ * <tt>null</tt> if the subprocess should inherit
+ * the working directory of the current process.
+ *
+ * @return A new {@link Process} object for managing the subprocess
+ *
+ * @throws SecurityException
+ * If a security manager exists and its
+ * {@link SecurityManager#checkExec checkExec}
+ * method doesn't allow creation of the subprocess
+ *
+ * @throws IOException
+ * If an I/O error occurs
+ *
+ * @throws NullPointerException
+ * If <code>cmdarray</code> is <code>null</code>,
+ * or one of the elements of <code>cmdarray</code> is <code>null</code>,
+ * or one of the elements of <code>envp</code> is <code>null</code>
+ *
+ * @throws IndexOutOfBoundsException
+ * If <code>cmdarray</code> is an empty array
+ * (has length <code>0</code>)
+ *
+ * @see ProcessBuilder
+ * @since 1.3
+ */
+ public Process exec(String[] cmdarray, String[] envp, File dir)
+ throws IOException {
+ return new ProcessBuilder(cmdarray)
+ .environment(envp)
+ .directory(dir)
+ .start();
+ }
+
+ /**
+ * Returns the number of processors available to the Java virtual machine.
+ *
+ * <p> This value may change during a particular invocation of the virtual
+ * machine. Applications that are sensitive to the number of available
+ * processors should therefore occasionally poll this property and adjust
+ * their resource usage appropriately. </p>
+ *
+ * @return the maximum number of processors available to the virtual
+ * machine; never smaller than one
+ * @since 1.4
+ */
+ public native int availableProcessors();
+
+ /**
+ * Returns the amount of free memory in the Java Virtual Machine.
+ * Calling the
+ * <code>gc</code> method may result in increasing the value returned
+ * by <code>freeMemory.</code>
+ *
+ * @return an approximation to the total amount of memory currently
+ * available for future allocated objects, measured in bytes.
+ */
+ public native long freeMemory();
+
+ /**
+ * Returns the total amount of memory in the Java virtual machine.
+ * The value returned by this method may vary over time, depending on
+ * the host environment.
+ * <p>
+ * Note that the amount of memory required to hold an object of any
+ * given type may be implementation-dependent.
+ *
+ * @return the total amount of memory currently available for current
+ * and future objects, measured in bytes.
+ */
+ public native long totalMemory();
+
+ /**
+ * Returns the maximum amount of memory that the Java virtual machine will
+ * attempt to use. If there is no inherent limit then the value {@link
+ * java.lang.Long#MAX_VALUE} will be returned. </p>
+ *
+ * @return the maximum amount of memory that the virtual machine will
+ * attempt to use, measured in bytes
+ * @since 1.4
+ */
+ public native long maxMemory();
+
+ /**
+ * Runs the garbage collector.
+ * Calling this method suggests that the Java virtual machine expend
+ * effort toward recycling unused objects in order to make the memory
+ * they currently occupy available for quick reuse. When control
+ * returns from the method call, the virtual machine has made
+ * its best effort to recycle all discarded objects.
+ * <p>
+ * The name <code>gc</code> stands for "garbage
+ * collector". The virtual machine performs this recycling
+ * process automatically as needed, in a separate thread, even if the
+ * <code>gc</code> method is not invoked explicitly.
+ * <p>
+ * The method {@link System#gc()} is the conventional and convenient
+ * means of invoking this method.
+ */
+ public native void gc();
+
+ /* Wormhole for calling java.lang.ref.Finalizer.runFinalization */
+ private static native void runFinalization0();
+
+ /**
+ * Runs the finalization methods of any objects pending finalization.
+ * Calling this method suggests that the Java virtual machine expend
+ * effort toward running the <code>finalize</code> methods of objects
+ * that have been found to be discarded but whose <code>finalize</code>
+ * methods have not yet been run. When control returns from the
+ * method call, the virtual machine has made a best effort to
+ * complete all outstanding finalizations.
+ * <p>
+ * The virtual machine performs the finalization process
+ * automatically as needed, in a separate thread, if the
+ * <code>runFinalization</code> method is not invoked explicitly.
+ * <p>
+ * The method {@link System#runFinalization()} is the conventional
+ * and convenient means of invoking this method.
+ *
+ * @see java.lang.Object#finalize()
+ */
+ public void runFinalization() {
+ runFinalization0();
+ }
+
+ /**
+ * Enables/Disables tracing of instructions.
+ * If the <code>boolean</code> argument is <code>true</code>, this
+ * method suggests that the Java virtual machine emit debugging
+ * information for each instruction in the virtual machine as it
+ * is executed. The format of this information, and the file or other
+ * output stream to which it is emitted, depends on the host environment.
+ * The virtual machine may ignore this request if it does not support
+ * this feature. The destination of the trace output is system
+ * dependent.
+ * <p>
+ * If the <code>boolean</code> argument is <code>false</code>, this
+ * method causes the virtual machine to stop performing the
+ * detailed instruction trace it is performing.
+ *
+ * @param on <code>true</code> to enable instruction tracing;
+ * <code>false</code> to disable this feature.
+ */
+ public native void traceInstructions(boolean on);
+
+ /**
+ * Enables/Disables tracing of method calls.
+ * If the <code>boolean</code> argument is <code>true</code>, this
+ * method suggests that the Java virtual machine emit debugging
+ * information for each method in the virtual machine as it is
+ * called. The format of this information, and the file or other output
+ * stream to which it is emitted, depends on the host environment. The
+ * virtual machine may ignore this request if it does not support
+ * this feature.
+ * <p>
+ * Calling this method with argument false suggests that the
+ * virtual machine cease emitting per-call debugging information.
+ *
+ * @param on <code>true</code> to enable instruction tracing;
+ * <code>false</code> to disable this feature.
+ */
+ public native void traceMethodCalls(boolean on);
+
+ /**
+ * Loads the specified filename as a dynamic library. The filename
+ * argument must be a complete path name,
+ * (for example
+ * <code>Runtime.getRuntime().load("/home/avh/lib/libX11.so");</code>).
+ * <p>
+ * First, if there is a security manager, its <code>checkLink</code>
+ * method is called with the <code>filename</code> as its argument.
+ * This may result in a security exception.
+ * <p>
+ * This is similar to the method {@link #loadLibrary(String)}, but it
+ * accepts a general file name as an argument rather than just a library
+ * name, allowing any file of native code to be loaded.
+ * <p>
+ * The method {@link System#load(String)} is the conventional and
+ * convenient means of invoking this method.
+ *
+ * @param filename the file to load.
+ * @exception SecurityException if a security manager exists and its
+ * <code>checkLink</code> method doesn't allow
+ * loading of the specified dynamic library
+ * @exception UnsatisfiedLinkError if the file does not exist.
+ * @exception NullPointerException if <code>filename</code> is
+ * <code>null</code>
+ * @see java.lang.Runtime#getRuntime()
+ * @see java.lang.SecurityException
+ * @see java.lang.SecurityManager#checkLink(java.lang.String)
+ */
+ public void load(String filename) {
+ load0(System.getCallerClass(), filename);
+ }
+
+ synchronized void load0(Class fromClass, String filename) {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkLink(filename);
+ }
+ if (!(new File(filename).isAbsolute())) {
+ throw new UnsatisfiedLinkError(
+ "Expecting an absolute path of the library: " + filename);
+ }
+ ClassLoader.loadLibrary(fromClass, filename, true);
+ }
+
+ /**
+ * Loads the dynamic library with the specified library name.
+ * A file containing native code is loaded from the local file system
+ * from a place where library files are conventionally obtained. The
+ * details of this process are implementation-dependent. The
+ * mapping from a library name to a specific filename is done in a
+ * system-specific manner.
+ * <p>
+ * First, if there is a security manager, its <code>checkLink</code>
+ * method is called with the <code>libname</code> as its argument.
+ * This may result in a security exception.
+ * <p>
+ * The method {@link System#loadLibrary(String)} is the conventional
+ * and convenient means of invoking this method. If native
+ * methods are to be used in the implementation of a class, a standard
+ * strategy is to put the native code in a library file (call it
+ * <code>LibFile</code>) and then to put a static initializer:
+ * <blockquote><pre>
+ * static { System.loadLibrary("LibFile"); }
+ * </pre></blockquote>
+ * within the class declaration. When the class is loaded and
+ * initialized, the necessary native code implementation for the native
+ * methods will then be loaded as well.
+ * <p>
+ * If this method is called more than once with the same library
+ * name, the second and subsequent calls are ignored.
+ *
+ * @param libname the name of the library.
+ * @exception SecurityException if a security manager exists and its
+ * <code>checkLink</code> method doesn't allow
+ * loading of the specified dynamic library
+ * @exception UnsatisfiedLinkError if the library does not exist.
+ * @exception NullPointerException if <code>libname</code> is
+ * <code>null</code>
+ * @see java.lang.SecurityException
+ * @see java.lang.SecurityManager#checkLink(java.lang.String)
+ */
+ public void loadLibrary(String libname) {
+ loadLibrary0(System.getCallerClass(), libname);
+ }
+
+ synchronized void loadLibrary0(Class fromClass, String libname) {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkLink(libname);
+ }
+ if (libname.indexOf((int)File.separatorChar) != -1) {
+ throw new UnsatisfiedLinkError(
+ "Directory separator should not appear in library name: " + libname);
+ }
+ ClassLoader.loadLibrary(fromClass, libname, false);
+ }
+
+ /**
+ * Creates a localized version of an input stream. This method takes
+ * an <code>InputStream</code> and returns an <code>InputStream</code>
+ * equivalent to the argument in all respects except that it is
+ * localized: as characters in the local character set are read from
+ * the stream, they are automatically converted from the local
+ * character set to Unicode.
+ * <p>
+ * If the argument is already a localized stream, it may be returned
+ * as the result.
+ *
+ * @param in InputStream to localize
+ * @return a localized input stream
+ * @see java.io.InputStream
+ * @see java.io.BufferedReader#BufferedReader(java.io.Reader)
+ * @see java.io.InputStreamReader#InputStreamReader(java.io.InputStream)
+ * @deprecated As of JDK 1.1, the preferred way to translate a byte
+ * stream in the local encoding into a character stream in Unicode is via
+ * the <code>InputStreamReader</code> and <code>BufferedReader</code>
+ * classes.
+ */
+ @Deprecated
+ public InputStream getLocalizedInputStream(InputStream in) {
+ return in;
+ }
+
+ /**
+ * Creates a localized version of an output stream. This method
+ * takes an <code>OutputStream</code> and returns an
+ * <code>OutputStream</code> equivalent to the argument in all respects
+ * except that it is localized: as Unicode characters are written to
+ * the stream, they are automatically converted to the local
+ * character set.
+ * <p>
+ * If the argument is already a localized stream, it may be returned
+ * as the result.
+ *
+ * @deprecated As of JDK 1.1, the preferred way to translate a
+ * Unicode character stream into a byte stream in the local encoding is via
+ * the <code>OutputStreamWriter</code>, <code>BufferedWriter</code>, and
+ * <code>PrintWriter</code> classes.
+ *
+ * @param out OutputStream to localize
+ * @return a localized output stream
+ * @see java.io.OutputStream
+ * @see java.io.BufferedWriter#BufferedWriter(java.io.Writer)
+ * @see java.io.OutputStreamWriter#OutputStreamWriter(java.io.OutputStream)
+ * @see java.io.PrintWriter#PrintWriter(java.io.OutputStream)
+ */
+ @Deprecated
+ public OutputStream getLocalizedOutputStream(OutputStream out) {
+ return out;
+ }
+
+}