RFR(M): 8165896: Use "open" flag from JVM_DefineModule to export all module packages

[Rachel Protacio]

Hi,

The jlrM changes have synched into jdk10 and there were a few 
discrepancies from my earlier changesets, so these are slightly updated 
webrevs. (I also found an extra spot in the jdk repo that needed deleting.)

Re-tested with JPRT and RBT tiers 2-5.

hotspot webrev: http://cr.openjdk.java.net/~rprotacio/8165896.01/
jdk webrev: http://cr.openjdk.java.net/~rprotacio/8165896.jdk.01/
root repo patch:

diff --git a/test/lib/sun/hotspot/WhiteBox.java 
b/test/lib/sun/hotspot/WhiteBox.java
--- a/test/lib/sun/hotspot/WhiteBox.java
+++ b/test/lib/sun/hotspot/WhiteBox.java
@@ -482,8 +482,8 @@
    }

    // Jigsaw
-  public native void DefineModule(Object module, String version, String 
location,
-                                  Object[] packages);
+  public native void DefineModule(Object module, boolean is_open, 
String version,
+                                  String location, Object[] packages);
    public native void AddModuleExports(Object from_module, String pkg, 
Object to_module);
    public native void AddReadsModule(Object from_module, Object 
source_module);
    public native void AddModulePackage(Object module, String pkg)

Thank you!
Rachel

On 3/23/2017 2:23 PM, Rachel Protacio wrote:
> Hello!
>
> Please review this enhancement, which implements the VM side of open 
> modules. Open modules export all their packages unqualifiedly, which 
> was previously done by exporting the packages one by one on the java 
> side. This change saves that step by adding an internal "open" 
> representation for the module structure, which is checked before 
> checking the exportedness of the package itself.
>
> JDK link: https://bugs.openjdk.java.net/browse/JDK-8165896
>
> hotspot webrev: http://cr.openjdk.java.net/~rprotacio/8165896.hotspot.00/
> jdk webrev: http://cr.openjdk.java.net/~rprotacio/8165896.jdk.00/
> root repo patch:
> --- old/test/lib/sun/hotspot/WhiteBox.java	2017-03-23 12:50:36.869963040 -0400
> +++ new/test/lib/sun/hotspot/WhiteBox.java	2017-03-23 12:50:36.421963021 -0400
> @@ -1,5 +1,5 @@
>   /*
> - * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
> + * Copyright (c) 2012, 2017, Oracle and/or its affiliates. All rights reserved.
>    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
>    *
>    * This code is free software; you can redistribute it and/or modify it
> @@ -449,8 +449,8 @@
>     }
>   
>     // Jigsaw
> -  public native void DefineModule(Object module, String version, String location,
> -                                  Object[] packages);
> +  public native void DefineModule(Object module, boolean is_open, String version,
> +                                  String location, Object[] packages);
>     public native void AddModuleExports(Object from_module, String pkg, Object to_module);
>     public native void AddReadsModule(Object from_module, Object source_module);
>     public native void AddModulePackage(Object module, String pkg);
>
> Testing:
>
>   * includes new regression test
>   * JPRT and RBT hotspot tiers 2-5
>
> Notes:
>
>   * This changeset re-conceptualizes the unnamed module as an open
>     module (as far as the internal representation is concerned). This
>     saves the VM from specifying every package in the unnamed module
>     as unqualifiedly exported.
>   * Additionally, automatic modules are defined as open modules in
>     terms of package exports. As such, in the jdk repo's Module.java
>     code, defineModule0() is called with isOpen==true for automatic
>     modules.
>   * In my search through module startup code, I found a for-loop in
>     modules.cpp that was looping through java.base packages just for
>     some logging. The entire loop should have been bounded by a
>     log_is_enabled() conditional. Since this patch is generally
>     improving the efficiency of modules startup, I corrected that here.
>   * Fixed a few comment typos I found along the way.
>
> Thank you!
> Rachel