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

[Mandy Chung]

Looks good.

Mandy

> On Oct 5, 2016, at 8:47 AM, Erik Joelsson <erik.joelsson at oracle.com> 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
>