/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. * * ident "%Z%%M% %I% %E% SMI" */ package org.opensolaris.os.dtrace; import java.io.*; import java.util.*; /** * Interface to the native DTrace library, each instance is a single * DTrace consumer. To consume the output of DTrace program actions, * {@link #addConsumerListener(ConsumerListener l) register a probe data * listener}. To get a snapshot of all aggregations in a D program on * your own programmatic interval without relying on DTrace actions to * generate that output, use the {@link #getAggregate()} method. * * @see ProbeData * @see Aggregate * * @author Tom Erickson */ public interface Consumer { /** * Optional flags passed to {@link #open(Consumer.OpenFlag[] flags) * open()}. */ public enum OpenFlag { /** * Generate 32-bit D programs. {@code ILP32} and {@link * Consumer.OpenFlag#LP64 LP64} are mutually exclusive. */ ILP32, /** * Generate 64-bit D programs. {@code LP64} and {@link * Consumer.OpenFlag#ILP32 ILP32} are mutually exclusive. */ LP64, }; /** * Opens this DTrace consumer. Optional flags indicate behaviors * that can only be set at the time of opening. Most optional * behaviors are set using {@link #setOption(String option, String * value) setOption()} after opening the consumer. In the great * majority of cases, the consumer is opened without specifying any * flags: * 
		{@code consumer.open();}
* Subsequent calls to set options, compile DTrace programs, enable * probes, and run this consumer may be made from any thread. * * @throws NullPointerException if any of the given open flags is * {@code null} * @throws IllegalArgumentException if any of the given flags are * mutually exlusive * @throws IllegalStateException if this consumer is closed or has * already been opened * @throws DTraceException if an exception occurs in the native * DTrace library * @see #compile(File program, String[] macroArgs) * @see #compile(String program, String[] macroArgs) * @see #enable() * @see #go() */ public void open(OpenFlag ... flags) throws DTraceException; /** * Compiles the given D program string. Optional macro arguments * replace corresponding numbered macro variables in the D program * starting at {@code $1}. * * @param program program string * @param macroArgs macro substitutions for $n placeholders * embedded in the given D program: {@code macroArgs[0]} replaces * all occurrences of {@code $1}, {@code macroArgs[1]} replaces all * occurrences of {@code $2}, and so on. {@code $0} is * automatically replaced by the executable name and should not be * included in the {@code macroArgs} parameter. See the * Macro Arguments section of the Scripting * chapter of the Solaris Dynamic Tracing Guide. * @return a non-null {@code Program} identifier that may be passed * to {@link #enable(Program program) enable()} * @throws NullPointerException if the given program string or any * of the given macro arguments is {@code null} * @throws IllegalStateException if called before {@link * #open(OpenFlag[] flags) open()} or after {@link #go()}, or if the * consumer is closed * @throws DTraceException if an exception occurs in the native * DTrace library * @see #compile(File program, String[] macroArgs) */ public Program compile(String program, String ... macroArgs) throws DTraceException; /** * Compiles the given D program file. Optional macro arguments * replace corresponding numbered macro variables in the D program * starting at {@code $1}. * * @param program program file * @param macroArgs macro substitutions for $n placeholders * embedded in the given D program: {@code macroArgs[0]} replaces * all occurrences of {@code $1}, {@code macroArgs[1]} replaces all * occurrences of {@code $2}, and so on. {@code $0} is * automatically set to the name of the given file and should not be * included in the {@code macroArgs} parameter. See the * Macro Arguments section of the Scripting * chapter of the Solaris Dynamic Tracing Guide. * @return a non-null {@code Program} identifier that may be passed * to {@link #enable(Program program) enable()} * @throws NullPointerException if the given program file or any of * the given macro arguments is {@code null} * @throws IllegalStateException if called before {@link * #open(OpenFlag[] flags) open()} or after {@link #go()}, or if the * consumer is closed * @throws DTraceException if an exception occurs in the native * DTrace library * @throws FileNotFoundException if the given program file cannot be * opened * @throws IOException if an I/O error occurs while reading the * contents of the given program file * @throws SecurityException if a security manager exists and its * {@code checkRead()} method denies read access to the file * @see #compile(String program, String[] macroArgs) */ public Program compile(File program, String ... macroArgs) throws DTraceException, IOException, SecurityException; /** * Enables all DTrace probes compiled by this consumer. Call {@code * enable()} with no argument to enable everything this consumer has * compiled so far (most commonly a single program, the only one to * be compiled). Call with one {@link Program} at a time if you * need information about enabled probes specific to each program. * * @throws IllegalStateException if called before compiling at least * one program, or if any compiled program is already enabled, or if * {@link #go()} was already called, or if this consumer is closed * @throws DTraceException if an exception occurs in the native * DTrace library * @see #enable(Program program) */ public void enable() throws DTraceException; /** * Enables DTrace probes matching the given program and attaches * information about those probes to the given program. A probe * matched multiple times (within the same D program or in multiple * D programs) triggers the actions associated with each matching * occurrence every time that probe fires. * * @param program A {@code Program} identifier returned by {@link * #compile(String program, String[] macroArgs) compile(String * program, ...)} or {@link #compile(File program, String[] * macroArgs) compile(File program, ...)}: If the given program is * {@code null}, the call has the same behavior as {@link #enable()} * with no argument; if the given program is non-null, the call * enables only those probes matching that program. In the latter * case, the {@code Program} parameter is modified as a way of * passing back information about the given program and its matching * probes, including program stability. * @throws IllegalArgumentException if the given program is non-null * and not compiled by this {@code Consumer} * @throws IllegalStateException if the given program is already * enabled (or if the given program is {@code null} and any * program is already enabled), or if {@link #go()} was already * called, or if this consumer is closed * @throws DTraceException if an exception occurs in the native * DTrace library * @see #compile(String program, String[] macroArgs) * @see #compile(File program, String[] macroArgs) * @see #enable() * @see #getProgramInfo(Program program) */ public void enable(Program program) throws DTraceException; /** * Attaches information about matching DTrace probes to the given * program. Attaches the same information to the given program as * that attached by {@link #enable(Program program)} but without * enabling the probes. * * @throws NullPointerException if the given program is {@code null} * @throws IllegalArgumentException if the given program was not * compiled by this {@code Consumer} * @throws IllegalStateException if called after {@link #close()} * @throws DTraceException if an exception occurs in the native * DTrace library * @see #compile(String program, String[] macroArgs) * @see #compile(File program, String[] macroArgs) * @see #enable(Program program) */ public void getProgramInfo(Program program) throws DTraceException; /** * Sets a boolean option. * * @throws NullPointerException if the given option is {@code null} * @throws DTraceException if a value is expected for the given * option, or if the option is otherwise invalid * @throws IllegalStateException if called before {@link * #open(OpenFlag[] flags) open()} or after {@link #close()}, or if * the given option is a boolean compile-time option and {@link * #go()} has already been called (see {@link Option} for a * breakdown of runtime and compile-time options) * @see #setOption(String option, String value) * @see #unsetOption(String option) */ public void setOption(String option) throws DTraceException; /** * Unsets a boolean option. * * @throws NullPointerException if the given option is {@code null} * @throws DTraceException if the given option is not a boolean * option, or if the option is otherwise invalid * @throws IllegalStateException if called before {@link * #open(OpenFlag[] flags) open()} or after {@link #close()}, or if * the given option is a boolean compile-time option and {@link * #go()} has already been called (see {@link Option} for a * breakdown of runtime and compile-time options) * @see #setOption(String option) */ public void unsetOption(String option) throws DTraceException; /** * Sets the value of a DTrace option. If the given option affects * compile-time behavior, it must be set before calling {@link * #compile(String program, String[] macroArgs) compile(String * program, ...)} or {@link #compile(File program, String[] * macroArgs) compile(File program, ...)} in order to have an effect * on compilation. Some runtime options including {@link * Option#switchrate switchrate} and {@link Option#aggrate aggrate} * are settable while a consumer is running; others must be set * before calling {@link #go()}. See the * Options and Tunables chapter of the Solaris Dynamic * Guide for information about specific options. * * @throws NullPointerException if the given option or value is * {@code null} * @throws IllegalStateException if called before {@link * #open(OpenFlag[] flags) open()} or after {@link #close()}, or if * the given option is a boolean compile-time option and {@code * go()} has already been called (see {@link Option} for a breakdown * of runtime and compile-time options) * @throws DTraceException for any of the following: * * * @see #open(OpenFlag[] flags) * @see #getOption(String option) * @see Option */ public void setOption(String option, String value) throws DTraceException; /** * Gets the value of a DTrace option. * * @throws NullPointerException if the given option is {@code null} * @throws IllegalStateException if called before {@link * #open(OpenFlag[] flags) open()} or after {@link #close()} * @throws DTraceException if the given option is invalid * @return the value of the given DTrace option: If the given option * is a boolean option and is currently unset, the returned value is * {@link Option#UNSET}. If the given option is a size * option, the returned value is in bytes. If the given option is a * time option, the returned value is in nanoseconds. If the * given option is {@link Option#bufpolicy bufpolicy}, the returned * value is one of {@link Option#BUFPOLICY_RING BUFPOLICY_RING}, * {@link Option#BUFPOLICY_FILL BUFPOLICY_FILL}, or {@link * Option#BUFPOLICY_SWITCH BUFPOLICY_SWITCH}. If the given option * is {@link Option#bufresize bufresize}, the returned value is one * of {@link Option#BUFRESIZE_AUTO BUFRESIZE_AUTO} or {@link * Option#BUFRESIZE_MANUAL BUFRESIZE_MANUAL}. * * @see #setOption(String option) * @see #unsetOption(String option) * @see #setOption(String option, String value) * @see Option */ public long getOption(String option) throws DTraceException; /** * Reports whether or not this consumer is open. * * @return {@code true} if and only if {@link #open(OpenFlag[] * flags) open()} has been called on this consumer and {@link * #close()} has not */ public boolean isOpen(); /** * Reports whether or not it is valid to call {@link #go()}. * * @return {@code true} if and only if at least one program has been * compiled, all compiled programs have been enabled, {@code go()} * has not already been called, and {@link #close()} has not been * called */ public boolean isEnabled(); /** * Reports whether or not this consumer is running. There may be a * delay after calling {@link #go()} before this consumer actually * starts running (listeners are notified by the {@link * ConsumerListener#consumerStarted(ConsumerEvent e) * consumerStarted()} method). * * @return {@code true} if this consumer is running, {@code false} * otherwise */ public boolean isRunning(); /** * Reports whether or not this consumer is closed. A closed * consumer cannot be reopened. *

* Note that a closed consumer is different from a consumer that has * not yet been opened. * * @return {@code true} if {@link #close()} has been called on this * consumer, {@code false} otherwise */ public boolean isClosed(); /** * Begin tracing and start a background thread to consume generated * probe data. * * @throws IllegalStateException if not {@link #isEnabled()} * @throws DTraceException if an exception occurs in the native * DTrace library * @see #go(ExceptionHandler h) * @see #open(OpenFlag[] flags) * @see #compile(String program, String[] macroArgs) * @see #compile(File program, String[] macroArgs) * @see #enable() * @see #stop() * @see #close() */ public void go() throws DTraceException; /** * Begin tracing and start a background thread to consume generated * probe data. Handle any exception thrown in the consumer thread * with the given handler. * * @throws IllegalStateException if not {@link #isEnabled()} * @throws DTraceException if an exception occurs in the native * DTrace library * @see #go() */ public void go(ExceptionHandler h) throws DTraceException; /** * Stops all tracing, as well as the background thread started by * {@link #go()} to consume generated probe data. A stopped * consumer cannot be restarted. It is necessary to {@code close()} * a stopped consumer to release the system resources it holds. *

* A consumer may stop on its own in response to the {@code exit()} * action (see {@code exit()} in the * Special Actions section of the Actions and * Subroutines chapter of the Solaris Dynamic Tracing * Guide). Similarly, a consumer stops automatically if it has * at least one target process and all its target processes have * completed (see {@link #createProcess(String command) * createProcess()} and {@link #grabProcess(int pid) * grabProcess()}). A consumer also stops automatically if it * encounters an exception while consuming probe data. In these * cases it is not necessary to call {@code stop()}. If a consumer * stops for any reason (an explicit call to {@code stop()} or any * of the reasons just given), listeners are notified through the * {@link ConsumerListener#consumerStopped(ConsumerEvent e) * consumerStopped()} method. *

* Note that a call to {@code stop()} blocks until the background * thread started by {@code go()} actually stops. After {@code * stop()} returns, a call to {@link #isRunning()} returns {@code * false}. If a {@code DTraceException} is thrown while stopping * this consumer, it is handled by the handler passed to {@link * #go(ExceptionHandler h)} (or a default handler if none is * specified). * * @throws IllegalStateException if called before {@link #go()} or * if {@code stop()} was already called * @see #go() * @see #abort() * @see #close() */ public void stop(); /** * Aborts the background thread started by {@link #go()}. {@code * abort()} is effectively the same as {@link #stop()} except that * it does not block (i.e. it does not wait until the background * thread actually stops). {@link #isRunning()} is likely {@code * true} immediately after a call to {@code abort()}, since an * aborted consumer stops at a time specified as later. * Specifically, a call to {@code abort()} stops tracing just before * the next {@link ConsumerListener#intervalBegan(ConsumerEvent e) * intervalBegan()} event and stops consuming probe data by the * subsequent {@link ConsumerListener#intervalEnded(ConsumerEvent e) * intervalEnded()} event. When the aborted consumer actually * stops, listeners are notified in the {@link * ConsumerListener#consumerStopped(ConsumerEvent e) * consumerStopped()} method, where it is convenient to {@link * #close()} the stopped consumer after requesting the final * aggregate. *

* The {@code abort()} and {@code stop()} methods have slightly * different behavior when called just after {@code go()} but * before the consumer actually starts running: It is * possible to {@code stop()} a consumer before it starts running * (resulting in a {@code consumerStopped()} event without a * matching {@code consumerStarted()} event), whereas an aborted * consumer will not stop until after it starts running, when it * completes a single interval (that interval does not include * sleeping to wait for traced probe data). Calling {@code abort()} * before {@code go()} is legal and has the same effect as calling * it after {@code go()} and before the consumer starts running. * The last behavior follows from the design: You do not know the * state of a consumer after calling {@code abort()}, nor is it * necessary to know the state of a consumer before calling {@code * abort()}. That may be preferable, for example, when you want to * abort a consumer opened and started in another thread. * * @see #stop() */ public void abort(); /** * Closes an open consumer and releases the system resources it was * holding. If the consumer is running, {@code close()} will {@link * #stop()} it automatically. A closed consumer cannot be * reopened. Closing a consumer that has not yet been opened makes * it illegal to open that consumer afterwards. It is a no-op to * call {@code close()} on a consumer that is already closed. * * @see #open(OpenFlag[] flags) */ public void close(); /** * Adds a listener for probe data generated by this consumer. */ public void addConsumerListener(ConsumerListener l); /** * Removes a listener for probe data generated by this consumer. */ public void removeConsumerListener(ConsumerListener l); /** * Gets a snapshot of all aggregations except those that have * already been captured in a {@link PrintaRecord}. Does not clear * any aggregation. *

* Provides a programmatic alternative to the {@code printa(}) * action (see * {@code printa()} in the Output Formatting * chapter of the Solaris Dynamic Tracing Guide). * * @throws IllegalStateException if called before {@link #go()} or * after {@link #close()} * @throws DTraceException if an exception occurs in the native * DTrace library * @see #getAggregate(Set includedAggregationNames, Set * clearedAggregationNames) */ public Aggregate getAggregate() throws DTraceException; /** * Gets a snapshot of all the specified aggregations except those * that have already been captured in a {@link PrintaRecord}. Does * not clear any aggregation. *

* Provides a programmatic alternative to the {@code printa(}) * action (see * {@code printa()} in the Output Formatting * chapter of the Solaris Dynamic Tracing Guide). * * @param includedAggregationNames if {@code null}, all available * aggregations are included; if non-null, only those aggregations * specifically named by the given set are included * @throws IllegalStateException if called before {@link #go()} or * after {@link #close()} * @throws DTraceException if an exception occurs in the native * DTrace library * @see #getAggregate(Set includedAggregationNames, Set * clearedAggregationNames) */ public Aggregate getAggregate(Set includedAggregationNames) throws DTraceException; /** * Gets a snapshot of all the specified aggregations except those * that have already been captured in a {@link PrintaRecord}, with * the side effect of atomically clearing any subset of those * aggregations. Clearing an aggregation resets all of its values * to zero without removing any of its keys. Leave aggregations * uncleared to get running totals, otherwise specify that an * aggregation be cleared to get values per time interval. Note * that once an aggregation is captured in a {@code PrintaRecord} * (as a result of the {@code printa()} action), it is no longer * available to the {@code getAggregate()} method. *

* Provides a programmatic alternative to the {@code printa(}) (see * * {@code printa()} in the Output Formatting * chapter of the Solaris Dynamic Tracing Guide) and {@code * clear()} actions. * * @param includedAggregationNames if {@code null}, all available * aggregations are included; if non-null, only those aggregations * specifically named by the given set are included * @param clearedAggregationNames if {@code null}, all available * aggregations are cleared; if non-null, only those aggregations * specifically named by the given set are cleared * @throws IllegalStateException if called before {@link #go()} or * after {@link #close()} * @throws DTraceException if an exception occurs in the native * DTrace library */ public Aggregate getAggregate(Set includedAggregationNames, Set clearedAggregationNames) throws DTraceException; /** * Creates a process by executing the given command on the system * and returns the created process ID. The created process is * suspended until calling {@link #go()} so that the process waits * to do anything until this consumer has started tracing (allowing * a process to be traced from the very beginning of its execution). * The macro variable {@code $target} in a D program will be * replaced by the process ID of the created process. When the * created process exits, this consumer notifies listeners through * the {@link ConsumerListener#processStateChanged(ProcessEvent e) * processStateChanged()} method. *

* See the * Target Process ID section of the Scripting * chapter of the Solaris Dynamic Tracing Guide. * * @param command a string whose first token is assumed to be the * name of the command and whose subsequent tokens are the arguments * to that command. * @return ID of the created process (pid) * @throws NullPointerException if the given command is {@code nul}l * @throws IllegalArgumentException if the given command is empty or * contains only whitespace * @throws IllegalStateException if called before {@link * #open(Consumer.OpenFlag[] flags) open()} or after {@link #go()}, * or if the consumer is closed * @throws DTraceException if the process cannot be created * @see #grabProcess(int pid) */ public int createProcess(String command) throws DTraceException; /** * Grabs the specified process and caches its symbol tables. The * macro variable {@code $target} in a D program will be replaced by * the process ID of the grabbed process. When the specified * process exits, this consumer notifies listeners through the * {@link ConsumerListener#processStateChanged(ProcessEvent e) * processStateChanged()} method. *

* See the * Target Process ID section of the Scripting * chapter of the Solaris Dynamic Tracing Guide. * * @param pid process ID of the process to be grabbed * @throws IllegalStateException if called before {@link * #open(Consumer.OpenFlag[] flags) open()} or after {@link #go()}, * or if the consumer is closed * @throws DTraceException if the process cannot be grabbed * @see #createProcess(String command) */ public void grabProcess(int pid) throws DTraceException; /** * Lists probes that match the given probe description. See {@link * ProbeDescription} for information about pattern syntax and * wildcarding. * * @param filter use {@link ProbeDescription#EMPTY} to get all * probes, otherwise get only those probes that match the given * filter * @return a non-null list of probe descriptions * @throws IllegalStateException if called before {@link * #open(Consumer.OpenFlag[] flags) open()} or after {@link #go()}, * or if the consumer is closed * @throws DTraceException if an exception occurs in the native * DTrace library * @see #open(OpenFlag[] flags) * @see #close() * @see #listProbeDetail(ProbeDescription filter) * @see #listProgramProbes(Program program) */ public List listProbes(ProbeDescription filter) throws DTraceException; /** * Lists probes that match the given probe description and includes * detail such as stability information about each listed probe. * * @param filter use {@link ProbeDescription#EMPTY} to get all * probes, otherwise get only those probes that match the given * filter * @return a non-null list of probe detail * @throws IllegalStateException if called before {@link * #open(Consumer.OpenFlag[] flags) open()} or after {@link #go()}, * or if the consumer is closed * @throws DTraceException if an exception occurs in the native * DTrace library * @see #listProbes(ProbeDescription filter) * @see #listProgramProbeDetail(Program program) */ public List listProbeDetail(ProbeDescription filter) throws DTraceException; /** * Lists probes that match the given compiled program. A probe * matches a D program if that program contains any matching probe * description. * * @param program a {@code Program} identifier returned by {@link * #compile(String program, String[] macroArgs) compile(String * program, ...)} or {@link #compile(File program, String[] * macroArgs) compile(File program, ...)} * @return a non-null list of probe descriptions * @throws NullPointerException if the given program identifier is * {@code null} * @throws IllegalArgumentException if the specified program was not * compiled by this consumer * @throws IllegalStateException if called before {@link * #open(Consumer.OpenFlag[] flags) open()} or after {@link #go()}, * or if the consumer is closed * @throws DTraceException if an exception occurs in the native * DTrace library * @see #listProbes(ProbeDescription filter) */ public List listProgramProbes(Program program) throws DTraceException; /** * Lists probes that match the given compiled program and includes * detail such as stability information about each listed probe. * * @param program a {@code Program} identifier returned by {@link * #compile(String program, String[] macroArgs) compile(String * program, ...)} or {@link #compile(File program, String[] * macroArgs) compile(File program, ...)} * @return a non-null list of probe detail * @throws NullPointerException if the given program identifier is * {@code null} * @throws IllegalArgumentException if the specified program was not * compiled by this consumer * @throws IllegalStateException if called before {@link * #open(Consumer.OpenFlag[] flags) open()} or after {@link #go()}, * or if the consumer is closed * @throws DTraceException if an exception occurs in the native * DTrace library * @see #listProgramProbes(Program program) * @see #listProbeDetail(ProbeDescription filter) */ public List listProgramProbeDetail(Program program) throws DTraceException; /** * Gets the kernel function name for the given 32-bit kernel * address. * * @param address 32-bit kernel function address, such as the value * of a {@link Tuple} member in an {@link AggregationRecord} to be * converted for display * @return the result of kernel function lookup as one of the * following:

where {@code module} and {@code * function} are names, and {@code offset} and {@code address} are * integers in hexadecimal format preceded by "{@code 0x}". {@code * offset} is the number of bytes from the beginning of the * function, included when non-zero. {@code address} is simply the * hex form of the input paramater, returned when function lookup * fails. The exact details of this format are subject to change. * @throws IllegalStateException if called before {@link #go()} or * after {@link #close()} * @see #lookupKernelFunction(long address) */ public String lookupKernelFunction(int address); /** * Gets the kernel function name for the given 64-bit kernel * address. * * @param address 64-bit kernel function address * @return kernel function name * @throws IllegalStateException if called before {@link #go()} or * after {@link #close()} * @see #lookupKernelFunction(int address) */ public String lookupKernelFunction(long address); /** * Gets the user function name for the given 32-bit user address and * process ID. * * @param pid ID of the user process containing the addressed * function * @param address 32-bit user function address, such as the value * of a {@link Tuple} member in an {@link AggregationRecord} to be * converted for display. * @return result of user function lookup as one of the * following: where {@code module} and {@code * function} are names, and {@code offset} and {@code address} are * integers in hexadecimal format preceded by "{@code 0x}". {@code * offset} is the number of bytes from the beginning of the * function, included when non-zero. {@code address} is simply the * hex form of the input paramater, returned when function lookup * fails. The exact details of this format are subject to change. * @throws IllegalStateException if called before {@link #go()} or * after {@link #close()} * @see #lookupUserFunction(int pid, long address) */ public String lookupUserFunction(int pid, int address); /** * Gets the user function name for the given 64-bit user address and * process ID. * * @param pid ID of the user process containing the addressed * function * @param address 64-bit user function address * @return user function name * @throws IllegalStateException if called before {@link #go()} or * after {@link #close()} * @see #lookupUserFunction(int pid, int address) */ public String lookupUserFunction(int pid, long address); /** * Gets the version of the native DTrace library. * * @return version string generated by the native DTrace library * (same as the output of {@code dtrace(1M)} with the {@code -V} * option) */ public String getVersion(); }