RFR: 8177845: Need a mechanism to load Graal

[Doug Simon]

Sure - how about good old Util? ;-) I'm open to other suggestions.

Sent from my iPhone

> On Apr 19, 2017, at 9:46 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
> 
> Hi Doug,
> 
> Can you consider using other name and not JDK9 for new JVMCI class? It will be used in JDK 10 too:
> 
> jdk.vm.ci.services.internal.JDK9;
> 
> Thanks,
> Vladimir
> 
>> On 4/18/17 3:13 PM, Doug Simon wrote:
>> Please review these changes that make jdk.internal.vm.compiler an upgradable compiler.
>> The primary requirement for this is to remove all usage of JDK internals from Graal.
>> While this most involves changes in Graal, there remain a few capabilities that must
>> be exposed via JVMCI. Namely:
>> 
>> 1. Graal needs a copy of jdk.internal.misc.VM.savedProps so that it can Graal initialize
>>   can use system properties that are guaranteed not to have been modified by application
>>   code (Graal initialization is lazy and may occur after application code has been run).
>> 
>> 2. Truffle needs to be able to trigger JVMCI initialization so that it can select the Graal
>>   optimized implementation of the Truffle runtime.
>> 
>> These capabilities have been added to jdk.vm.ci.services.Services. A comment has
>> also been added to this class to denote the current methods to be removed
>> in a subsequent bug to update the JDK copy of Graal with the upstream version which
>> no longer uses the methods. The methods destined for removal are:
>> 
>> exportJVMCITo(Class<?> requestor)
>> load(Class<S> service)
>> loadSingle(Class<S> service, boolean required)
>> 
>> The first one is no longer needed as JVMCI exports itself to Graal service providers
>> it loads via private API and Graal re-exports[1] JVMCI to any module the extends Graal.
>> The latter 2 are no longer required as Graal uses the standard ServiceLoader. This API
>> is only useful for JVMCI-8 where a hidden JVMCI class loader is used.
>> 
>> These changes have been tested against upstream Graal. To make the Graal tests pass, 2 extra
>> minor changes were required:
>> 
>> 1. In JDK-8177663, HotSpotMemoryAccessProviderImpl::checkRead was added and throws IllegalArgumentException
>>   on all error paths except one which throws AssertionError. The latter was a mistake and has been
>>   fixed to also throw IllegalArgumentException.
>> 2. An invalid assertion has been removed from HotSpotResolvedObjectTypeImpl::isDefinitelyResolvedWithRespectTo.
>>   Up to JDK 8, it was true that all classes in java.* packages were loaded by the boot class loader.
>>   This is no longer true in JDK 9 with classes like java.sql being loaded by platform class loader.
>> 
>> As hinted above, a subsequent bug will be required to pull in the latest upstream Graal and
>> remove use of JDK internal API from the jdk.aot module. The qualified exports to
>> jdk.vm.internal.compiler and jdk.aot can then be removed.
>> 
>> -Doug
>> 
>> https://bugs.openjdk.java.net/browse/JDK-8177845
>> http://cr.openjdk.java.net/~dnsimon/8177845/
>> 
>> [1] http://openjdk.java.net/projects/jigsaw/spec/issues/#IndirectQualifiedReflectiveAccess
>> 
>> 
>>