RFR: 8146001: Remove support for command line options from JVMCI

[Christian Thalinger]

> On Jan 4, 2016, at 12:31 PM, Doug Simon <doug.simon at oracle.com> wrote:
> 
>> 
>> On 04 Jan 2016, at 18:41, Christian Thalinger <christian.thalinger at oracle.com> wrote:
>> 
>>> 
>>> On Jan 4, 2016, at 7:19 AM, Christian Thalinger <christian.thalinger at oracle.com> wrote:
>>> 
>>>> 
>>>> On Jan 4, 2016, at 7:16 AM, Christian Thalinger <christian.thalinger at oracle.com> wrote:
>>>> 
>>>>> 
>>>>> On Dec 22, 2015, at 4:50 AM, Doug Simon <doug.simon at oracle.com> wrote:
>>>>> 
>>>>> The effort of maintaining JVMCI across different JDK versions (including a potential backport to JDK7) is reduced by making JVMCI as small as possible. The support for command line options in JVMCI (based around the @Option annotation) is a good candidate for removal: 
>>>>> 
>>>>> 1. It’s almost entirely implemented on top of system properties and so can be made to work without VM support. 
>>>>> 2. JVMCI itself only currently uses 3 options which can be replaced with usage of sun.misc.VM.getSavedProperty(). The latter ensures application code can’t override JVMCI properties set on the command line.
>>>>> 
>>>>> This change removes the JVMCI command line option support.
>>>>> 
>>>>> https://bugs.openjdk.java.net/browse/JDK-8146001
>>>>> http://cr.openjdk.java.net/~dnsimon/8146001/
>>>> 
>>>> +    private static final boolean TrustFinalDefaultFields = HotSpotJVMCIRuntime.getBooleanProperty(TrustFinalDefaultFieldsProperty, true);
>>>> 
>>>> +    private static final boolean ImplicitStableValues = HotSpotJVMCIRuntime.getBooleanProperty("jvmci.ImplicitStableValues", true);
>>>> 
>>>> We should either use the jvmci. prefix or not.
>>> 
>>> Sorry, I was reading the patch wrong.  Of course both use the jvmci. prefix.
>> 
>> I think we should prefix the property name in getBooleanProperty:
>> 
>> +    public static boolean getBooleanProperty(String name, boolean def) {
>> +        String value = VM.getSavedProperty("jvmci." + name);
> 
> Ok, sounds reasonable.
> 
>> 
>> and I put UseProfilingInformation back:
>> 
>> diff -r 0fcfe4b07f7e src/jdk.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotResolvedJavaMethodImpl.java
>> --- a/src/jdk.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotResolvedJavaMethodImpl.java	Tue Dec 29 18:30:51 2015 +0100
>> +++ b/src/jdk.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotResolvedJavaMethodImpl.java	Mon Jan 04 07:40:46 2016 -1000
>> @@ -24,7 +24,6 @@ package jdk.vm.ci.hotspot;
>> 
>> import static jdk.vm.ci.hotspot.CompilerToVM.compilerToVM;
>> import static jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.runtime;
>> -import static jdk.vm.ci.hotspot.HotSpotResolvedJavaMethod.Options.UseProfilingInformation;
>> import static jdk.vm.ci.hotspot.HotSpotVMConfig.config;
>> import static jdk.vm.ci.hotspot.UnsafeAccess.UNSAFE;
>> 
>> @@ -65,6 +64,11 @@ import jdk.vm.ci.meta.TriState;
>> final class HotSpotResolvedJavaMethodImpl extends HotSpotMethod implements HotSpotResolvedJavaMethod, HotSpotProxified, MetaspaceWrapperObject {
>> 
>>     /**
>> +     * Whether to use profiling information.
>> +     */
>> +    private static final boolean UseProfilingInformation = HotSpotJVMCIRuntime.getBooleanProperty("UseProfilingInformation", true);
>> +
>> +    /**
>>      * Reference to metaspace Method object.
>>      */
>>     private final long metaspaceMethod;
>> @@ -424,7 +428,7 @@ final class HotSpotResolvedJavaMethodImp
>>     public ProfilingInfo getProfilingInfo(boolean includeNormal, boolean includeOSR) {
>>         ProfilingInfo info;
>> 
>> -        if (UseProfilingInformation.getValue() && methodData == null) {
>> +        if (UseProfilingInformation && methodData == null) {
>>             long metaspaceMethodData = UNSAFE.getAddress(metaspaceMethod + config().methodDataOffset);
>>             if (metaspaceMethodData != 0) {
>>                 methodData = new HotSpotMethodData(metaspaceMethodData, this);
> 
> JVMCI should unconditionally return available profiling information. It's up to the compiler whether or not to use it. For example, this is now compilation local in Graal:
> 
> http://hg.openjdk.java.net/graal/graal-compiler/rev/f35e653aa876#l16.16 <http://hg.openjdk.java.net/graal/graal-compiler/rev/f35e653aa876#l16.16>

Oh, I missed that.  Yes, that works for us as well.  Thanks for pointing that out.

> 
> -Doug

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