RFR: 8177845: Need a mechanism to load Graal

[Peter Levart]

Hi Alan,

On 04/19/2017 03:41 PM, Alan Bateman wrote:
> On 19/04/2017 08:37, Peter Levart wrote:
>
>> :
>>
>> Note that Properties class is thread-safe, while HashMap isn't. But I 
>> think this should not be a problem here, as during initPhase1(), as 
>> far as I know, no threads apart from main thread are started yet (is 
>> this true?), so anyone accessing getSavedProperty(ies) will either be 
>> the main thread itself or a thread started afterwards, so there is a 
>> happens-before relationship.
> The ReferenceHandler and Finalizer threads are started early, before 
> initPhase1. However, both should immediately block and in the case of 
> the Finalizer, await the completion of initPhase1 before polling.
>
> -Alan

Just out of curiosity, what guarantees are there that no code before 
VM.saveAndRemoveProperties() ever executes Integer.valueOf(int) method 
for example? Note that this call is implicitly hidden in autoboxing of 
int(s)...

If this happens, then class initialization of Integer.IntegerCache may 
fail, because it is using VM.getSavedProperty():

     public static String getSavedProperty(String key) {
         if (savedProps.isEmpty())
             throw new IllegalStateException("Should be non-empty if 
initialized");

         return savedProps.getProperty(key);
     }

Hm....

Peter