Upgrade to Pro — share decks privately, control downloads, hide ads and more …

Beyond JVM

headius
December 05, 2013

Beyond JVM

Talk on interesting JVM-related upcoming technologies as delivered at YOW! Melbourne 2013.

headius

December 05, 2013
Tweet

More Decks by headius

Other Decks in Technology

Transcript

  1. Reminders • Green/yellow/red rating system after talk • Extended Q/A

    by blue chairs at 12:15 • If not green…stop by and tell me why
  2. Me • Charles Oliver Nutter • Red Hat (yes, I

    have one; no, I don’t wear it) • JRuby and JVM languages • JVM hacking and spelunking • @headius
  3. Goals • Get you excited about the future of JVM

    • Show you there are very few unsolvables • Convince you to get involved
  4. What is “JVM”? • The JVM is software that runs

    JVM bytecode • Java, Scala, Groovy, JRuby, Clojure, … • OpenJDK contains Sun’s JVM “HotSpot” • Oracle’s JDK is based on OpenJDK • Many other JVMs exist for many platforms • Some just replace HotSpot
  5. OSS JVMs • Avian • Azul Zulu • CACAO •

    Dalvik • GCJ • HaikuVM • HotSpot • IcedTea • IKVM.NET • Jamiga • JamVM • Jaos • Jato VM • Jelatine JVM • JESSICA • Jikes RVM (Jikes Research Virtual Machine) • JOP • Juice • Jupiter • JwiK • Kaffe • leDos • MateVM • Maxine • Mika VM • miniMV • Mysaifu • NanoVM • RoboVM • SableVM • Squawk virtual machine • SuperWaba • TakaTuka • TinyVM. • VM02
  6. OpenJDK Timeline • For years, Sun’s JDK is closed source

    • Sun Microsystems starts OSS process in 2005 • Official announcement at JavaOne 2006 • HotSpot OSSed 12 Nov 2006 • JDK OSSed 8 May 2007
  7. A 2006 report prepared for the EU by UNU-MERIT stated

    that Sun was the largest corporate contributor to open source movements in the world.
  8. According to this report, Sun's open source contributions exceed the

    combined total of the next five largest commercial contributors.
  9. Sun Becomes Oracle • Sun broke open the OSS piñata

    • Java, Solaris, OpenOffice, NetBeans, VirtualBox, ZFS, Dtrace, and more • Unable to capitalize on OSS • Hardware can’t make up the difference • Oracle takes over Sun…oh no!!!
  10. Java SE 7 Updates 0 22.5 45 67.5 90 7u1

    7u2 7u3 7u4 7u5 7u6 7u7 7u9 7u10 7u11 7u13 7u15 7u17 7u21 7u25 7u40 7u45 Time since last release Flurry of exploits New numbering 9mo of security releases
  11. The OpenJDK landscape looks different this year. Oracle's complete grip

    on OpenJDK is slowly loosening. They're still the dominant player and perhaps always will be, but things are more level than they were.! ! - Andrew Haley of Red Hat! ! Upon nomination to the OpenJDK governing board for 2013
  12. Truths of OpenJDK • It is really truly OSS, under

    GPL+CPE • You can fork it • You can distribute builds of it • You can contribute to it • Oracle is learning how to do OSS
  13. Java 7 Features • Strings in switch statements • More

    numeric literal forms • Type inference for generic instances • try-with-resources statement • Multiple-catch
  14. static String chooseGreeting(String language) {" switch (language) {" case "Java":

    return "I love to hate you!";" case "Scala": return "I love you, I think!";" case "Clojure": return "(love I you)";" case "Groovy": return "I love ?: you";" case "Ruby": return "I.love? you # => true";" default: return "Who are you?";" }" }
  15. public static void doSort(List<String> input) {" Collections.sort(input,! (a,b)->Integer.compare(a.length(), b.length()));" }"

    " public static String getInitials(List<String> input) {" return input.stream()" .map(x->x.substring(0,1))" .collect(Collectors.joining());" }
  16. Java 9 Features? • Modularization? • Dynamic invocation? • Value

    types? • Reified generics? • Coroutines? (working patch available!) • Tail calls? (working patch available!)
  17. Ported Languages • Ada • AWK • BASIC • BBx

    • Boo • C • COBOL • ColdFusion • Railo • Open BlueDragon • Common Lisp • Component Pascal • Erlang • Forth • Go • Haxe • JavaScript • Logo • Lua • Yeti ML • Oberon-2 • OCaml • Object Pascal • PHP • Prolog • Python • R • REXX • Ruby • Scheme • Smalltalk • Tcl
  18. New Languages • Alef++ • Ateji PX • BBj •

    BeanShell • Ceylon • CAL • E • Fantom • Flow Java. • Fortress • Frege • Frink • Golo • Gosu • Hecl • Ioke • KBML • Kotlin • Jabaco • Jaskell • Jelly • Join Java • Joy • Judoscript • Libretto. • Mirah • N.A.M.E. Basic. • NetLogo • Nice • Noop • ObjectScript • PHP.reboot • Pizza • Pnuts • Processing • Stab • Sleep • V • X10 • Xtend • Zest
  19. public class GetPidJNI {" public static native long getpid();" "

    public static void main( String[] args ) {" getpid();" }" " static {" System.load(! System.getProperty("user.dir") +! "/getpidjni.dylib");" }" } JNI
  20. /* DO NOT EDIT THIS FILE - it is machine

    generated */" #include <jni.h>" /* Header for class com_headius_jnr_presentation_GetPidJNI */" " #ifndef _Included_com_headius_jnr_presentation_GetPidJNI" #define _Included_com_headius_jnr_presentation_GetPidJNI" #ifdef __cplusplus" extern "C" {" #endif" /*" * Class: com_headius_jnr_presentation_GetPidJNI" * Method: getpid" * Signature: ()J" */" JNIEXPORT jlong JNICALL Java_com_headius_jnr_1presentation_GetPidJNI_getpid" (JNIEnv *, jclass);" " #ifdef __cplusplus" }" #endif" #endif JNI
  21. $ gcc -I $JAVA_HOME/include -I $JAVA_HOME/include/darwin -L $JAVA_HOME/jre/lib/ -dynamiclib -ljava

    -o getpidjni.dylib com_headius_jnr_presentation_GetPidJNI. c" ! $ java -Djava.library.path=`pwd` -cp target/jnr_presentation-1.0- SNAPSHOT.jar com.headius.jnr_presentation.GetPidJNI JNI
  22. Java Native Runtime • Java API • for calling Native

    code • supported by a rich Runtime library • You may be familiar with JNA • Foreign Function Interface (FFI) • https://github.com/jnr • Maven artifacts for everything
  23. Justifications • NIO, NIO.2 • Native IO, symlinks, FS-walking, •

    Unmanaged memory • Selectable stdio, process IO • Low-level or other sockets (UNIX, ICMP, ...) • New APIs (graphics, crypto, OS, ...)
  24. import jnr.ffi.LibraryLoader;" import jnr.ffi.annotations.IgnoreError;" " public class GetPidJNRExample {" public

    interface GetPid {" long getpid();" }" " public static void main( String[] args ) {" GetPid getpid = LibraryLoader" .create(GetPid.class)! .load("c");" " getpid.getpid();" }" } JNR
  25. JNR Platforms • Darwin (OS X): universal (+ppc?) • Linux:

    i386, x86_64, arm, ppc, ppc64, s390x • Windows: i386, x86_64 • FreeBSD, OpenBSD: i386, x86_64 • SunOS: i386, x86_64, sparc, sparcv9 • AIX: ppc • OpenVMS, AS/400: builds out there somewhere • If your platform isn't here, contribute a build
  26. jnr-ffi • User-oriented API • Roughly equivalent to what JNA

    gives you • Functions, structs, callbacks, memory • https://github.com/jnr/jnr-ffi
  27. import jnr.ffi.LibraryLoader;" import jnr.ffi.annotations.IgnoreError;" " public class GetPidJNRExample {" public

    interface GetPid {" long getpid();" }" " public static void main( String[] args ) {" GetPid getpid = LibraryLoader" .create(GetPid.class)! .load("c");" " getpid.getpid();" }" } jnr-ffi
  28. jnr-posix • Pre-bound set of POSIX functions • Mostly driven

    by what JRuby, Jython use • Goal: 100% of POSIX bound to Java
  29. public int chmod(String string, int i);" public int chown(String string,

    int i, int i1);" public int execv(String string, String[] strings);" public int execve(String string, String[] strings, String[] strings1);" public int fork();" public int seteuid(int i);" public int getgid();" public String getlogin();" public int getpgid();" public int getpgid(int i);" public int getpgrp();" public int getpid();" public int getppid();" public Passwd getpwent();! public Passwd getpwuid(int i);! public Passwd getpwnam(String string);" public Group getgrgid(int i);! public Group getgrnam(String string);" public int getuid();! public boolean isatty(FileDescriptor fd);" public int kill(int i, int i1);! public int symlink(String string, String string1);" public int link(String string, String string1);" public String readlink(String string) throws IOException;" public String getenv(String string);" public int setenv(String string, String string1, int i);" public int unsetenv(String string);" public int getpriority(int i, int i1);" public int setpriority(int i, int i1, int i2);" public int setuid(int i);" public FileStat stat(String string);" public int stat(String string, FileStat fs);" public int umask(int i);" public Times times();" public int utimes(String string, long[] longs, long[] longs1);" public int waitpid(int i, int[] ints, int i1);" public int wait(int[] ints);" public int errno();" public void errno(int i);" public int posix_spawnp(String string, List<? extends SpawnFileAction> list, List<? extends CharSequence> list1, List<? extends CharSequence> list2);
  30. public interface POSIXHandler {! public void error(Errno errno, String string);"

    public void unimplementedError(String string);! public void warn(WARNING_ID wrngd, String string, Object[] os);" public boolean isVerbose();! public File getCurrentWorkingDirectory();! public String[] getEnv();! public InputStream getInputStream();! public PrintStream getOutputStream();! public int getPID();! public PrintStream getErrorStream();" }
  31. jnr-enxio • Extended Native X-platform IO • NIO-compatible JNR-backed IO

    library • Read, write, select (kqueue, epoll, etc) • Low-level fcntl control • https://github.com/jnr/jnr-enxio
  32. public class NativeSocketChannel" extends AbstractSelectableChannel" implements ByteChannel, NativeSelectableChannel {" public

    NativeSocketChannel(int fd);! public NativeSocketChannel(int fd, int ops);! public final int validOps();! public final int getFD();! public int read(ByteBuffer dst) throws IOException;" public int write(ByteBuffer src) throws IOException" public void shutdownInput() throws IOException;" public void shutdownOutput() throws IOException;! }
  33. jnr-unixsocket • UNIX sockets for NIO • Built atop jnr-enxio

    • Fully selectable, etc • https://github.com/jnr/jnr-unixsocket
  34. import jnr.ffi.LibraryLoader;" import jnr.ffi.annotations.IgnoreError;" " public class GetPidJNRExample {" public

    interface GetPid {" @IgnoreError" long getpid();" }" " public static void main( String[] args ) {" GetPid getpid = LibraryLoader" .create(GetPid.class)! .load("c");" " getpid.getpid();" }" } @IgnoreError
  35. getpid calls, 100M times 0ms 500ms 1000ms 1500ms 2000ms JNR

    getpid JNI JNR @IgnoreError GCC -O3 But There's More to Do
  36. JVM Help is Coming • Standard FFI API in JDK

    • JIT intelligence • Drop JNI overhead where possible • Bind native call directly at call site • Security policies, segv protection, etc • Time for an FFI JSR
  37. Recap • OpenJDK is awesome • Java is evolving •

    JVM languages are everywhere • Even native code is accessible
  38. History • JVM authors mentioned non-Java languages • Language authors

    have targeted JVM • Hundreds of JVM languages now • But JVM was a mismatch for many of them • Usually required tricks that defeated JVM optimizations • Or required features JDK could not provide
  39. JVM Opcodes Invocation invokevirtual" invokeinterface" invokestatic" invokespecial Field Access getfield"

    setfield" getstatic" setstatic Array Access *aload" *astore" b,s,c,i,l,d,f,a Stack Local Vars Flow Control Allocation Boolean and Numeric
  40. Goals of JSR 292 • A user-definable bytecode • Full

    freedom to define VM behavior • Fast method pointers + adapters • Optimizable like normal Java code • Avoid future modifications
  41. + Method Pointers and Adapters Faster than reflection, with user-defined

    argument, flow, and exception handling A User-definable Bytecode You decide how the JVM implements it
  42. VM Operations Method Lookup Type Checking Branch Method Cache Method

    Invocation Target Object Object’s Class void foo() static void bar() instanceof obj.foo() JVM void foo() Call Site
  43. // Static" System.currentTimeMillis()" Math.log(1.0)" " // Virtual" "hello".toUpperCase()" System.out.println()" "

    // Interface" myList.add("happy happy")" myRunnable.run()" " // Special" new ArrayList()" super.equals(other)
  44. // Static" invokestatic java/lang/System.currentTimeMillis:()J" invokestatic java/lang/Math.log:(D)D" ! // Virtual" invokevirtual

    java/lang/String.toUpperCase:()Ljava/lang/String;" invokevirtual java/io/PrintStream.println:()V" ! // Interface" invokeinterface java/util/List.add:(Ljava/lang/Object;)Z" invokeinterface java/lang/Runnable.add:()V" ! // Special" invokespecial java/util/ArrayList.<init>:()V" invokespecial java/lang/Object.equals:(java/lang/Object)Z invokestatic invokevirtual invokeinterface invokespecial
  45. invokestatic" 1. Confirm arguments are of correct type 2. Look

    up method on Java class 3. Cache method 4. Invoke method invokevirtual" 1. Confirm object is of correct type 2. Confirm arguments are of correct type 3. Look up method on Java class 4. Cache method 5. Invoke method invokeinterface" 1. Confirm object’s type implements interface 2. Confirm arguments are of correct type 3. Look up method on Java class 4. Cache method 5. Invoke method invokespecial" 1. Confirm object is of correct type 2. Confirm arguments are of correct type 3. Confirm target method is visible 4. Look up method on Java class 5. Cache method 6. Invoke method invokestatic invokevirtual invokeinterface invokespecial invokedynamic! 1. Call bootstrap handle (your code) 2. Bootstrap prepares CallSite + MethodHandle 3. MethodHandle invoked now and future (until CallSite changes)
  46. Indy Languages • New language impls • JavaScript: Dyn.js and

    Nashorn • Redline Smalltalk • Improved language performance • JRuby, Groovy, Jython • Java features too!
  47. Times Faster than Ruby 1.9.3 0 1.25 2.5 3.75 5

    base64 richards neural redblack 4.32 3.66 3.44 2.658 1.565 1.914 1.538 1.346 JRuby/Java 6 JRuby/Java 7
  48. red/black tree, pure Ruby versus native ruby-2.0.0 + Ruby ruby-2.0.0

    + C ext jruby + Ruby Runtime per iteration 0 0.75 1.5 2.25 3 0.29s 0.51s 2.48s
  49. Caveat Emptor • Indy was really slow in first Java

    7 release • Got fast in 7u2...and turned out broken • Rewritten for 7u40 • Slow to warm up • Still some issues (memory use, etc) • Java 8 due in March…
  50. Out of our control Written in C++ JVM Bytecode JVM

    Language Bytecode Interpreter Bytecode JIT Native Code
  51. What If… • The JVM’s JIT optimizer were written in

    Java • You could customize how the JIT works for your language or library • JITed code could directly make native calls
  52. Graal • A 100% Java-based JIT framework • Grew out

    of the 100% Java “Maxine” JVM • Backends to assembly or HotSpot IR • Directly control code generation • Build a language without using JVM bytecode • http://openjdk.java.net/projects/graal/
  53. Graal Intermediate Representation JVM Language Graal Optimizer Native Code Your

    Transformations Your Optimizations Plain Java APIs Under your control
  54. However… • Not everyone is a compiler writer • Graal’s

    IR is low-level and nontrivial • Need to understand JVM internals • Need some understanding of CPU
  55. Without JVM • Design your language • Work out memory

    model • Create an optimizing compiler • Spend ten years debugging it • PROFIT
  56. With JVM • Design your language • Maybe write an

    interpreter • Compile to JVM bytecode • Pray that the JVM optimizes it right • PROFIT
  57. Truffle • Language framework built on Graal • Designed to

    fulfill the dream • Implement interpreter • Truffle feeds that to backend • No compiler expertise needed • https://wiki.openjdk.java.net/display/Graal/Truffle+FAQ+and+Guidelines
  58. Traditional Approach Any JVM Custom made bytecode compiler Guest Language

    AST interpreter in pure Java Bytecode emitted by guest language
  59. Truffle Atop JVM Any JVM Truffle Guest Language AST interpreter

    in pure Java Bytecode based on interpreter flow
  60. Truffle Atop Graal Graal JVM Truffle Guest Language AST interpreter

    in pure Java Direct access to compiler internals, IR, machine code cache, on stack replacement, etc etc
  61. The Final Word • JVM is a powerful platform •

    Java and other languages are evolving • The JVM is adapting to our needs • New tools breaking JVM’s boundaries