Building The Android Runtime (ART) For Mac OS X: Part Eight — Testing, Testing

Having got the Android Runtime to build, eventually, does it actually work ?

Running art the immediate answer is no,

    $art
    E/JniInvocation(46765): Failed to dlopen libart.so: dlopen(libart.so, 2): image not found
    Failed to initialize JNI invocation API from libart.so

The art executable is a script which contains the following so it looks as though this problem is easily fixed.

    ...
    
    invoke_with=
    DALVIKVM=dalvikvm
    LIBART=libart.so
    
    ...

Trying again after modifying the art script appropriately we get

    $art
    art I 46796 66656 art/runtime/gc/space/image_space.cc:269] RelocateImage: \
        /Users/simon/Scratch/art/out/host/darwin-x86/bin/../bin/patchoat \
            --input-image-location=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.art \
            --output-image-file=/Users/simon/Scratch/xper/art/android-data46788/dalvik-cache/x86_64/Users@simon@Scratch@art@out@host@darwin-x86@bin@..@framework@core.art \
            --input-oat-location=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.oat \
            --output-oat-file=/Users/simon/Scratch/xper/art/android-data46788/dalvik-cache/x86_64/Users@simon@Scratch@art@out@host@darwin-x86@bin@..@framework@core.oat \
            --instruction-set=x86_64 --base-offset-delta=9420800
    patchoat W 46797 66657 art/runtime/gc/heap.cc:216] \
        Could not create image space with image file '/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.art'. \
        Attempting to fall back to imageless running. \
        Error was: Failed to load /system image '/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/x86_64/core.art': \
            Failed to mmap at expected address, mapped at 0x100b06000 instead of 0x60000000

and then it hangs/spins.

The address

    0x100b06000

in the error message from patchoat shows that it is a 64-bit executable, so it needs to be rebuilt as a 32-bit executable.

Modifying the file

    art/patchoat/Android.mk

in the same way as we did for dex2oat, rebuilding and trying again, remembering to specify that we want to use a 32-bit VM, we get

    $art --32
    art I 24835 34536 art/runtime/gc/space/image_space.cc:269] RelocateImage: \
        /Users/simon/Scratch/art/out/host/darwin-x86/bin/../bin/patchoat \
            --input-image-location=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.art \
            --output-image-file=/Users/simon/Scratch/xper/art/android-data24827/dalvik-cache/x86/Users@simon@Scratch@art@out@host@darwin-x86@bin@..@framework@core.art \
            --input-oat-location=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.oat \
            --output-oat-file=/Users/simon/Scratch/xper/art/android-data24827/dalvik-cache/x86/Users@simon@Scratch@art@out@host@darwin-x86@bin@..@framework@core.oat \
            --instruction-set=x86 \
            --base-offset-delta=-11399168
    Class name required

which is definitely an improvement.

Trying again with

   -help

to find out how to actually run something we get a long list of arguments we can use and an equally long list of arguments we cannot.

    $art --32 -help
    dalvikvm: [options] class [argument ...]

    The following standard options are supported:
      -classpath classpath (-cp classpath)
      -Dproperty=value
      -verbose:tag ('gc', 'jni', or 'class')
      -showversion
      -help
      -agentlib:jdwp=options

    The following extended options are supported:
      -Xrunjdwp:<options>
      -Xbootclasspath:bootclasspath
      -Xcheck:tag  (e.g. 'jni')
      -XmsN (min heap, must be multiple of 1K, >= 1MB)
      -XmxN (max heap, must be multiple of 1K, >= 2MB)
      -XssN (stack size)
      -Xint
    
    The following Dalvik options are supported:
      -Xzygote
      -Xjnitrace:substring (eg NativeClass or nativeMethod)
      -Xstacktracefile:<filename>
      -Xgc:[no]preverify
      -Xgc:[no]postverify
      -XX:HeapGrowthLimit=N
      -XX:HeapMinFree=N
      -XX:HeapMaxFree=N
      -XX:NonMovingSpaceCapacity=N
      -XX:HeapTargetUtilization=doublevalue
      -XX:ForegroundHeapGrowthMultiplier=doublevalue
      -XX:LowMemoryMode
      -Xprofile:{threadcpuclock,wallclock,dualclock}
        
    The following unique to ART options are supported:
      -Xgc:[no]preverify_rosalloc
      -Xgc:[no]postsweepingverify_rosalloc
      -Xgc:[no]postverify_rosalloc
      -Xgc:[no]presweepingverify
      -Ximage:filename
      -XX:+DisableExplicitGC
      -XX:ParallelGCThreads=integervalue
      -XX:ConcGCThreads=integervalue
      -XX:MaxSpinsBeforeThinLockInflation=integervalue
      -XX:LongPauseLogThreshold=integervalue
      -XX:LongGCLogThreshold=integervalue
      -XX:DumpGCPerformanceOnShutdown
      -XX:IgnoreMaxFootprint
      -XX:UseTLAB
      -XX:BackgroundGC=none
      -XX:LargeObjectSpace={disabled,map,freelist}
      -XX:LargeObjectThreshold=N
      -Xmethod-trace
      -Xmethod-trace-file:filename  -Xmethod-trace-file-size:integervalue
      -Xenable-profiler
      -Xprofile-filename:filename
      -Xprofile-period:integervalue
      -Xprofile-duration:integervalue
      -Xprofile-interval:integervalue
      -Xprofile-backoff:doublevalue
      -Xprofile-start-immediately
      -Xprofile-top-k-threshold:doublevalue
      -Xprofile-top-k-change-threshold:doublevalue
      -Xprofile-type:{method,stack}
      -Xprofile-max-stack-depth:integervalue
      -Xcompiler:filename
      -Xcompiler-option dex2oat-option
      -Ximage-compiler-option dex2oat-option
      -Xpatchoat:filename
      -X[no]relocate
      -X[no]dex2oat (Whether to invoke dex2oat on the application)
      -X[no]image-dex2oat (Whether to create and use a boot image)
        
    The following previously supported Dalvik options are ignored:
      -ea[:<package name>... |:<class name>]
      -da[:<package name>... |:<class name>]
      (-enableassertions, -disableassertions)
      -esa
      -dsa
      (-enablesystemassertions, -disablesystemassertions)
      -Xverify:{none,remote,all}
      -Xrs
      -Xint:portable, -Xint:fast, -Xint:jit
      -Xdexopt:{none,verified,all,full}
      -Xnoquithandler
      -Xjniopts:{warnonly,forcecopy}
      -Xjnigreflimit:integervalue
      -Xgc:[no]precise
      -Xgc:[no]verifycardtable
      -X[no]genregmap
      -Xverifyopt:[no]checkmon
      -Xcheckdexsum
      -Xincludeselectedop
      -Xjitop:hexopvalue[-endvalue][,hexopvalue[-endvalue]]*
      -Xincludeselectedmethod
      -Xjitthreshold:integervalue
      -Xjitcodecachesize:decimalvalueofkbytes
      -Xjitblocking
      -Xjitmethod:signature[,signature]* (eg Ljava/lang/String\;replace)
      -Xjitclass:classname[,classname]*
      -Xjitoffset:offset[,offset]
      -Xjitconfig:filename
      -Xjitcheckcg
      -Xjitverbose
      -Xjitprofile
      -Xjitdisableopt
      -Xjitsuspendpoll
      -XX:mainThreadStackSize=N

Writing a very simple ‘hello world’

    package xper.hw;
    
    public final class HelloWorldART
    {
        public static void main(String[] theArgs)
        {
            System.out.println("Hello World courtesy of the Android Runtime (ART)");
            System.exit(0);
        }
    }

and turning it to a .dex and trying again we get

    art --32 -classpath hw.dex xper.hw.HelloWorldART
    art I 24871 35716 art/runtime/gc/space/image_space.cc:269] RelocateImage: \
        /Users/simon/Scratch/art/out/host/darwin-x86/bin/../bin/patchoat \
            --input-image-location=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.art \
            --output-image-file=/Users/simon/Scratch/xper/art/android-data24863/dalvik-cache/x86/Users@simon@Scratch@art@out@host@darwin-x86@bin@..@framework@core.art\
            --input-oat-location=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.oat \
            --output-oat-file=/Users/simon/Scratch/xper/art/android-data24863/dalvik-cache/x86/Users@simon@Scratch@art@out@host@darwin-x86@bin@..@framework@core.oat --instruction-set=x86\
            --base-offset-delta=-4640768
    dex2oat I 24873 35749 art/dex2oat/dex2oat.cc:1266] \
        /Users/simon/Scratch/art/out/host/darwin-x86/bin/../bin/dex2oat \
            --runtime-arg -classpath \
            --runtime-arg hw.dex \
            --instruction-set=x86 \
            --instruction-set-features=default \
            --runtime-arg -Xrelocate
            --host \
            --boot-image=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.art \
            --dex-file=/Users/simon/Scratch/xper/art/hw.dex \
            --oat-fd=3 \
            --oat-location=/Users/simon/Scratch/xper/art/android-data24863/dalvik-cache/x86/Users@simon@Scratch@xper@art@hw.dex
    dex2oat I 24873 35749 art/dex2oat/dex2oat.cc:284] dex2oat took 246.341ms (threads: 8)
    Hello World courtesy of the Android Runtime (ART)
    art I 24871 35716 art/runtime/native/java_lang_Runtime.cc:41] System.exit called, status: 0

And there you have it. Possibly the longest and most convoluted way of getting a Java ‘hello world’ program to run short of writing your own Java runtime.

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Copyright (c) 2014 By Simon Lewis. All Rights Reserved.

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