Sponsor request: Always pass java.library.path when running micro benchmarks

[Jorn Vernee]

Hi,

Please sponsor the following patch that correctly passes 
java.library.path when running micro benchmarks [1].

As a little bit of background; previously the java.library.path was 
appended to $1_MICRO_JAVA_OPTIONS and this was passed to the java VM 
running the JMH jar. But, the problem with this is that the path is not 
passed on to the forks that are created by JMH, so it only works when 
running without forks.

As a fix for this, the java.library.path was instead appended to 
JMH_JVM_ARGS which is ultimately passed to JMH using the -jvmArgs 
option, which will make sure it is passed to the forks created by JMH as 
well.

Unfortunately, it was moved into the same if block that checks whether 
either MICRO_VM_OPTIONS or MICRO_JAVA_OPTIONS was set on the command 
line, before appending their values to JMH_JVM_ARGS as well. This means 
that if MICRO_VM_OPTIONS or MICRO_JAVA_OPTIONS are not set, 
java.library.path will not be passed to JMH either. This was not a 
problem in our use case since we needed to set VM_OPTIONS for the 
benchmark any ways. But it should still be fixed to make benchmarks that 
don't use VM_OPTIONS, but _do_ use native libraries work, and to avoid a 
confusing linkage error if the VM_OPTIONS argument is forgotten.

As a fix, I now unconditionally set $1_JMH_JVM_ARGS to include 
java.library.path, and then conditionally append MICRO_VM_OPTIONS or 
MICRO_JAVA_OPTIONS if they were set. Note that I also added the '$1_' 
prefix to JMH_JVM_ARGS to make it local to the current macro expansion 
(it seems like this was forgotten before).

Testing: verifying that with and without setting VM_OPTIONS, 
java.library.path is set when running the benchmarks.

Thanks,
Jorn

[1] :

diff --git a/make/RunTests.gmk b/make/RunTests.gmk
index ccd9632ad4f..805de4dd785 100644
--- a/make/RunTests.gmk
+++ b/make/RunTests.gmk
@@ -687,13 +687,15 @@ define SetupRunMicroTestBody
      $1_MICRO_BASIC_OPTIONS += -rff 
$$($1_TEST_RESULTS_DIR)/jmh-result.$(MICRO_RESULTS_FORMAT)
    endif

+  # Set library path for native dependencies
+  $1_JMH_JVM_ARGS := -Djava.library.path=$$(TEST_IMAGE_DIR)/micro/native
+
    ifneq ($$(MICRO_VM_OPTIONS)$$(MICRO_JAVA_OPTIONS), )
-    JMH_JVM_ARGS := $$(MICRO_VM_OPTIONS) $$(MICRO_JAVA_OPTIONS)
-    # Set library path for native dependencies
-    JMH_JVM_ARGS += -Djava.library.path=$$(TEST_IMAGE_DIR)/micro/native
-    $1_MICRO_VM_OPTIONS := -jvmArgs $(call ShellQuote,$$(JMH_JVM_ARGS))
+    $1_JMH_JVM_ARGS += $$(MICRO_VM_OPTIONS) $$(MICRO_JAVA_OPTIONS)
    endif

+  $1_MICRO_VM_OPTIONS := -jvmArgs $(call ShellQuote,$$($1_JMH_JVM_ARGS))
+
    ifneq ($$(MICRO_ITER), )
      $1_MICRO_ITER := -i $$(MICRO_ITER)
    endif