RFR: JDK-8167195: VM fails to initialize intermittently when running jmod to create some images

[Tim Bell]

Erik:

> Thanks for all the reviews, but unfortunately I wasn't satisfied with
> the below solution. The combination of the buildjdk and interim-image is
> getting really complex, and adding the optimize step is not making it
> easier. Here is what I think is a good solution. It should be more
> correct and also retain as much opportunity for concurrency as possible.
>
> http://cr.openjdk.java.net/~erikj/8167195/webrev.01/
>
> I tried to clarify each of the hard to understand dependencies with
> thorough comments.

Thanks, Erik.  Looks good to me.

/Tim

>
> /Erik
>
> On 2016-10-05 17:47, Erik Joelsson wrote:
>> Hello,
>>
>> Please review this small patch, which should fix an issue introduced
>> by JDK-8166948. At least on Windows, running jmod on the exploded
>> image may fail if the new optimization target is running concurrently.
>> I had missed adjusting the dependencies for the jmod targets.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8167195
>>
>> Patch:
>>
>> diff -r 4bd1866d819b make/Main.gmk
>> --- a/make/Main.gmk
>> +++ b/make/Main.gmk
>> @@ -615,15 +615,19 @@
>>    $(foreach m, $(LAUNCHER_MODULES), $(eval $m-jmod: $m-launchers))
>>    $(foreach m, $(COPY_MODULES), $(eval $m-jmod: $m-copy))
>>
>> -  # Jmods cannot be created until we have the jlink tool ready to
>> run, which requires
>> -  # all java modules to be compiled and jdk.jlink-launchers.
>> -  # And we also need to copy jvm.cfg (done in java.base-copy) and
>> tzdb.dat (done in
>> -  # java.base-gendata) to the appropriate location otherwise jimage,
>> jlink and jmod won't start.
>> +  # Jmods cannot be created until we have the jlink tool ready to
>> run. During
>> +  # the build we run it from the exploded image. To be runnable, all
>> java
>> +  # modules and jdk.jlink-launchers need to be built. We also need to
>> copy
>> +  # jvm.cfg (done in java.base-copy) and tzdb.dat (done in
>> java.base-gendata)
>> +  # to the appropriate location otherwise jimage, jlink and jmod
>> won't start.
>>    $(JMOD_TARGETS): java.base-libs java.base-copy java.base-gendata
>> jdk.jlink-launchers
>> -  # When creating a BUILDJDK, the java compilation has already been
>> done by the
>> -  # normal build and copied in.
>> +  # The above is enough when creating a BUILDJDK since the java
>> modules have
>> +  # been compiled by the normal build and copied in. In the normal,
>> non cross
>> +  # compiling case, jmod execution has to wait until the exploded-image
>> +  # is completely done. Otherwise the optimization target may be
>> changing
>> +  # module-info.class files while a jmod instance is trying to read
>> them.
>>    ifneq ($(CREATING_BUILDJDK), true)
>> -    $(JMOD_TARGETS): java
>> +    $(JMOD_TARGETS): exploded-image
>>    endif
>>
>>    ifeq ($(CREATE_BUILDJDK), true)