RFR: JDK-8144039: Enable javac server by default

[Magnus Ihse Bursie]

On 2015-11-25 15:11, Erik Joelsson wrote:
> Hello,
>
> The --enable-javac-server feature seems to be working well and is 
> providing considerable speedup when building the JDK. We should make 
> the option enabled by default.
>
> As an example, on my local machine, a run of "make exploded-image" 
> without javac server took 00:04:09 and with javac server 00:03:20. On 
> machines with less cpus I have seen even bigger improvements.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8144039
> Patch:
> diff -r 358fb90ae6e6 common/autoconf/build-performance.m4
> --- a/common/autoconf/build-performance.m4
> +++ b/common/autoconf/build-performance.m4
> @@ -413,7 +413,7 @@
>
>    AC_ARG_ENABLE([javac-server], [AS_HELP_STRING([--enable-javac-server],
>        [use only the server part of sjavac for faster javac compiles 
> @<:@disabled@:>@])],
> -      [ENABLE_JAVAC_SERVER="${enableval}"], [ENABLE_JAVAC_SERVER="no"])
> +      [ENABLE_JAVAC_SERVER="${enableval}"], [ENABLE_JAVAC_SERVER="yes"])
>    if test "x$JVM_ARG_OK" = "xfalse"; then
>      AC_MSG_WARN([Could not set -Xms${MS_VALUE}M -Xmx${MX_VALUE}M, 
> disabling javac server])
>      ENABLE_JAVAC_SERVER="no"
> diff -r 358fb90ae6e6 common/autoconf/generated-configure.sh

I like that you enable javac-server by default. But the patch was a bit 
too hurried. :)

When you change the default value, you are also in fact reversing the 
logic of the configure option. As in other such options, the string 
listed for AS_HELP_STRING should be "--disable-javac-server", and the 
default value listed should be "enabled".

/Magnus