Better tools for adjusting to strong encapsulation

Thu Mar 23 09:23:31 UTC 2017

I will interpret your answer as that there is no additional per method 
invocation cost due to this.

bye Jochen

On 23.03.2017 09:12, Alan Bateman wrote:
> On 22/03/2017 21:07, Jochen Theodorou wrote:
>
>> the warnings you are seeing are from the groovy runtime trying to
>> determine - in a pre JDK9 compatible way - if it is allowed to call
>> the methods on Objecz. This happens in a first step by setAccessible
>> on all methods using the array version, and if that fails by using the
>> normal setAccessible on each method (which will contribute to much
>> longer startup times). At no point our runtime or the program you
>> wrote are trying to call finalize, clone or registerNatives.
> This sounds like Object.class.getDeclaredMethods() and then invoking
> setAccessible(true) on every method, is that right? If so then it will
> trigger warnings for non-public methods. Is there any reason why this
> code couldn't just look at the modifiers? Claes mentions the new
> canAccess which might be useful going forward.
>
>>
>> The only one we are to be blamed for is
>> MethodHandles$Lookup(java.lang.Class,int), for which I haven´t
>> implemented the alternative yet
>>
>> If you did other programs... like for example running a gradle
>> build... you would see many many more such lines
> Lots of lines but not clear to me that it's Gradle that wants to hack
> into every non-public member of java.util.ArrayList.
>
> $ gradle
> NOTE: Picked up the following options via JDK_JAVA_OPTIONS:
>   --permit-illegal-access
> WARNING: --permit-illegal-access will be removed in the next major release
> WARNING: Illegal access by org.gradle.internal.reflect.JavaMethod
> (file:/gradle-3.4.1/lib/gradle-base-services-3.4.1.jar) to method
> java.lang.ClassLoader.getPackages() (permitted by --permit-illegal-access)
> Starting a Gradle Daemon, 1 stopped Daemon could not be reused, use
> --status for details
> WARNING: Illegal access by org.gradle.internal.reflect.JavaMethod
> (file:/gradle-3.4.1/lib/gradle-base-services-3.4.1.jar) to method
> java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int)
> (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.lang.Object.finalize() (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.lang.Object.clone() (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.lang.Object.registerNatives() (permitted by --permit-illegal-access)
> WARNING: Illegal access by org.codehaus.groovy.vmplugin.v7.Java7$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to constructor
> java.lang.invoke.MethodHandles$Lookup(java.lang.Class,int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by org.gradle.internal.reflect.JavaMethod
> (file:/gradle-3.4.1/lib/gradle-base-services-3.4.1.jar) to method
> java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int)
> (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.AbstractCollection.hugeCapacity(int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.AbstractCollection.finishToArray(java.lang.Object[],java.util.Iterator)
> (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.AbstractList.subListRangeCheck(int,int,int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.AbstractList.removeRange(int,int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.AbstractList.rangeCheckForAdd(int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.AbstractList.outOfBoundsMsg(int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.add(java.lang.Object,java.lang.Object[],int)
> (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.access$000(java.util.ArrayList) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.elementAt(java.lang.Object[],int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.readObject(java.io.ObjectInputStream) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.writeObject(java.io.ObjectOutputStream) (permitted
> by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.newCapacity(int) (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.hugeCapacity(int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.removeIf(java.util.function.Predicate,int,int)
> (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.removeRange(int,int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.rangeCheckForAdd(int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.outOfBoundsMsg(int,int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.outOfBoundsMsg(int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.elementData(int) (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.grow() (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.grow(int) (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.nBits(int) (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.setBit(long[],int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.isClear(long[],int) (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.shiftTailOverGap(java.lang.Object[],int,int)
> (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.checkInvariants() (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.fastRemove(int) (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$3$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to method
> java.util.ArrayList.batchRemove(java.util.Collection,boolean,int,int)
> (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$1$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to field
> java.util.AbstractCollection.MAX_ARRAY_SIZE (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$1$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to field
> java.util.AbstractList.modCount (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$1$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to field
> java.util.ArrayList.serialVersionUID (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$1$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to field
> java.util.ArrayList.DEFAULT_CAPACITY (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$1$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to field
> java.util.ArrayList.EMPTY_ELEMENTDATA (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$1$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to field
> java.util.ArrayList.DEFAULTCAPACITY_EMPTY_ELEMENTDATA (permitted by
> --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$1$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to field
> java.util.ArrayList.elementData (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$1$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to field
> java.util.ArrayList.size (permitted by --permit-illegal-access)
> WARNING: Illegal access by
> org.codehaus.groovy.reflection.CachedClass$1$1
> (file:/gradle-3.4.1/lib/groovy-all-2.4.7.jar) to field
> java.util.ArrayList.MAX_ARRAY_SIZE (permitted by --permit-illegal-access)
> :help
>
> Welcome to Gradle 3.4.1.
>
> To run a build, run gradle <task> ...
>
> To see a list of available tasks, run gradle tasks
>
> To see a list of command-line options, run gradle --help
>
> To see more detail about a task, run gradle help --task <task>
>
> BUILD SUCCESSFUL
>
> Total time: 3.584 secs
>
>
>>
>> So it will not be on a invocation base with some kind of check if that
>> has been locked already? Then I misunderstood
> Once setAccessible succeeds then further use of that AccessiblecObject
> does not do an access check so there won't be subsequent warnings.
>
>
>> :
>>
>> So you tell me that if I add an add-opens to java.base for all unnamed
>> modules, I will still pay a performance penalty here? on each method
>> invocation or only once?
> A discussion point is whether the precise options (--add-exports and
> --add-opens) triggers warnings in JDK 9 or not. If they do not then
> there will be no performance overhead.
>
> -Alan