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

[Erik Joelsson]

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.

/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)
>
>
> /Erik
>