tamed: TAMED_JAVA_OPTS: New environment variable

This will be passed to dslc and then to the JVM.  The intent is to permit
fine-grained heap ratio tuning.

RELEASES.md

@@ -16,6 +16,15 @@ commits that introduce the changes.  To make a new release, run
 
 NEXT
 ====
+This release provides a new environment variable for JVM tuning.  It does
+not provide any new compiler features or performance enhancements in itself,
+though it enables optimizations through JVM tuning.
+
+Compiler
+--------
+- The new environment variable `TAMED_JAVA_OPTS` can now be used to provide
+  arguments to the JVM.  This feature was added to support heap ratio
+  tuning.
 
 Miscellaneous
 -------------

bin/dslc.in

@@ -37,6 +37,6 @@ rater-path()
 
 
 CLASSPATH="$CLASSPATH:@DSLC_CLASSPATH@:$dslc_jar" \
-  "@JAVA@" @JAVA_OPTS@ \
+  "@JAVA@" @JAVA_OPTS@ $JAVA_OPTS \
   com.lovullo.dslc.DslCompiler \
   "$( rater-path )"

bin/tame

@@ -36,6 +36,7 @@ declare -ri TAME_CMD_WAITTIME="${TAME_CMD_WAITTIME:-3}"
 # propagate to daemon
 export TAMED_STALL_SECONDS
 export TAMED_SPAWNER_PID
+export TAMED_JAVA_OPTS
 
 
 # Send a single command to the next available runner and

bin/tamed

@@ -32,6 +32,10 @@ declare -ri TAMED_STALL_SECONDS="${TAMED_STALL_SECONDS:-1}"
 # id of process that indirectly spawned tamed (default $PPID)
 declare -ri TAMED_SPAWNER_PID="${TAMED_SPAWNER_PID:-$PPID}"
 
+# options to pass to JVM via dslc
+declare -r TAMED_JAVA_OPTS="${TAMED_JAVA_OPTS:-}"
+export JAVA_OPTS="$TAMED_JAVA_OPTS"
+
 # set by `main', global for `cleanup'
 declare root=
 
@@ -258,6 +262,7 @@ Environment Variables:
                         runner is automatically killed (default 1)
   TAMED_SPAWNER_PID     inhibit stalling while this process is running
                         (default PPID)
+  TAMED_JAVA_OPTS       opts to pass to dslc, and in turn, the JVM
 EOF
 
   exit $EX_USAGE

build-aux/Makefile.am

@@ -95,6 +95,7 @@ SHELL = /bin/bash -O extglob -O nullglob
 # propagate to tame{,d}
 export TAME_CMD_WAITTIME
 export TAMED_STALL_SECONDS
+export TAMED_JAVA_OPTS
 
 TAMED_SPAWNER_PID=$(shell echo $$PPID)
 export TAMED_SPAWNER_PID