8242273: Shenandoah: accept either SATB or IU barriers, but not both

Reviewed-by: rkennke

src/hotspot/share/gc/shenandoah/heuristics/shenandoahAggressiveHeuristics.cpp

@@ -43,12 +43,6 @@ ShenandoahAggressiveHeuristics::ShenandoahAggressiveHeuristics() : ShenandoahHeu
   if (ClassUnloading) {
     SHENANDOAH_ERGO_OVERRIDE_DEFAULT(ShenandoahUnloadClassesFrequency, 1);
   }
-
-  // Final configuration checks
-  SHENANDOAH_CHECK_FLAG_SET(ShenandoahLoadRefBarrier);
-  SHENANDOAH_CHECK_FLAG_SET(ShenandoahSATBBarrier || ShenandoahStoreValEnqueueBarrier);
-  SHENANDOAH_CHECK_FLAG_SET(ShenandoahCASBarrier);
-  SHENANDOAH_CHECK_FLAG_SET(ShenandoahCloneBarrier);
 }
 
 void ShenandoahAggressiveHeuristics::choose_collection_set_from_regiondata(ShenandoahCollectionSet* cset,

src/hotspot/share/gc/shenandoah/heuristics/shenandoahCompactHeuristics.cpp

@@ -41,12 +41,6 @@ ShenandoahCompactHeuristics::ShenandoahCompactHeuristics() : ShenandoahHeuristic
   SHENANDOAH_ERGO_OVERRIDE_DEFAULT(ShenandoahUncommitDelay,        1000);
   SHENANDOAH_ERGO_OVERRIDE_DEFAULT(ShenandoahGuaranteedGCInterval, 30000);
   SHENANDOAH_ERGO_OVERRIDE_DEFAULT(ShenandoahGarbageThreshold,     10);
-
-  // Final configuration checks
-  SHENANDOAH_CHECK_FLAG_SET(ShenandoahLoadRefBarrier);
-  SHENANDOAH_CHECK_FLAG_SET(ShenandoahSATBBarrier || ShenandoahStoreValEnqueueBarrier);
-  SHENANDOAH_CHECK_FLAG_SET(ShenandoahCASBarrier);
-  SHENANDOAH_CHECK_FLAG_SET(ShenandoahCloneBarrier);
 }
 
 bool ShenandoahCompactHeuristics::should_start_gc() const {

src/hotspot/share/gc/shenandoah/heuristics/shenandoahStaticHeuristics.cpp

@@ -34,12 +34,6 @@
 ShenandoahStaticHeuristics::ShenandoahStaticHeuristics() : ShenandoahHeuristics() {
   SHENANDOAH_ERGO_ENABLE_FLAG(ExplicitGCInvokesConcurrent);
   SHENANDOAH_ERGO_ENABLE_FLAG(ShenandoahImplicitGCInvokesConcurrent);
-
-  // Final configuration checks
-  SHENANDOAH_CHECK_FLAG_SET(ShenandoahLoadRefBarrier);
-  SHENANDOAH_CHECK_FLAG_SET(ShenandoahSATBBarrier || ShenandoahStoreValEnqueueBarrier);
-  SHENANDOAH_CHECK_FLAG_SET(ShenandoahCASBarrier);
-  SHENANDOAH_CHECK_FLAG_SET(ShenandoahCloneBarrier);
 }
 
 ShenandoahStaticHeuristics::~ShenandoahStaticHeuristics() {}

src/hotspot/share/gc/shenandoah/shenandoahHeuristics.hpp

@@ -55,14 +55,6 @@
     }                                                                       \
   } while (0)
 
-#define SHENANDOAH_CHECK_FLAG_SET(name)                                     \
-  do {                                                                      \
-    if (!(name)) {                                                          \
-      err_msg message("Heuristics needs -XX:+" #name " to work correctly"); \
-      vm_exit_during_initialization("Error", message);                      \
-    }                                                                       \
-  } while (0)
-
 class ShenandoahCollectionSet;
 class ShenandoahHeapRegion;
 

src/hotspot/share/gc/shenandoah/shenandoahIUMode.cpp

@@ -38,14 +38,19 @@ void ShenandoahIUMode::initialize_flags() const {
     FLAG_SET_DEFAULT(VerifyBeforeExit, false);
   }
 
-  FLAG_SET_DEFAULT(ShenandoahStoreValEnqueueBarrier, true);
-  FLAG_SET_DEFAULT(ShenandoahSATBBarrier, false);
+  if (FLAG_IS_DEFAULT(ShenandoahStoreValEnqueueBarrier)) {
+    FLAG_SET_DEFAULT(ShenandoahStoreValEnqueueBarrier, true);
+  }
+  if (FLAG_IS_DEFAULT(ShenandoahSATBBarrier)) {
+    FLAG_SET_DEFAULT(ShenandoahSATBBarrier, false);
+  }
 
   SHENANDOAH_ERGO_ENABLE_FLAG(ExplicitGCInvokesConcurrent);
   SHENANDOAH_ERGO_ENABLE_FLAG(ShenandoahImplicitGCInvokesConcurrent);
 
   // Final configuration checks
   SHENANDOAH_CHECK_FLAG_SET(ShenandoahLoadRefBarrier);
+  SHENANDOAH_CHECK_FLAG_UNSET(ShenandoahSATBBarrier);
   SHENANDOAH_CHECK_FLAG_SET(ShenandoahStoreValEnqueueBarrier);
   SHENANDOAH_CHECK_FLAG_SET(ShenandoahCASBarrier);
   SHENANDOAH_CHECK_FLAG_SET(ShenandoahCloneBarrier);

src/hotspot/share/gc/shenandoah/shenandoahMode.hpp

@@ -29,6 +29,22 @@
 
 class ShenandoahHeuristics;
 
+#define SHENANDOAH_CHECK_FLAG_SET(name)                                     \
+  do {                                                                      \
+    if (!(name)) {                                                          \
+      err_msg message("GC mode needs -XX:+" #name " to work correctly");    \
+      vm_exit_during_initialization("Error", message);                      \
+    }                                                                       \
+  } while (0)
+
+#define SHENANDOAH_CHECK_FLAG_UNSET(name)                                   \
+  do {                                                                      \
+    if ((name)) {                                                           \
+      err_msg message("GC mode needs -XX:-" #name " to work correctly");    \
+      vm_exit_during_initialization("Error", message);                      \
+    }                                                                       \
+  } while (0)
+
 class ShenandoahMode : public CHeapObj<mtGC> {
 public:
   virtual void initialize_flags() const = 0;

src/hotspot/share/gc/shenandoah/shenandoahNormalMode.cpp

@@ -43,6 +43,7 @@ void ShenandoahNormalMode::initialize_flags() const {
 
   // Final configuration checks
   SHENANDOAH_CHECK_FLAG_SET(ShenandoahLoadRefBarrier);
+  SHENANDOAH_CHECK_FLAG_UNSET(ShenandoahStoreValEnqueueBarrier);
   SHENANDOAH_CHECK_FLAG_SET(ShenandoahSATBBarrier);
   SHENANDOAH_CHECK_FLAG_SET(ShenandoahCASBarrier);
   SHENANDOAH_CHECK_FLAG_SET(ShenandoahCloneBarrier);

test/hotspot/jtreg/gc/shenandoah/options/TestWrongBarrierDisable.java

@@ -46,6 +46,7 @@ public static void main(String[] args) throws Exception {
         };
         String[] iu = {
                 "ShenandoahLoadRefBarrier",
+                "ShenandoahStoreValEnqueueBarrier",
                 "ShenandoahCASBarrier",
                 "ShenandoahCloneBarrier",
         };
@@ -71,7 +72,7 @@ private static void shouldFailAll(String h, String[] barriers) throws Exception
             );
             OutputAnalyzer output = new OutputAnalyzer(pb.start());
             output.shouldNotHaveExitValue(0);
-            output.shouldContain("Heuristics needs ");
+            output.shouldContain("GC mode needs ");
             output.shouldContain("to work correctly");
         }
     }

test/hotspot/jtreg/gc/shenandoah/options/TestWrongBarrierEnable.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2020, Red Hat, Inc. 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+/* @test TestWrongBarrierEnable
+ * @summary Test that disabling wrong barriers fails early
+ * @key gc
+ * @requires vm.gc.Shenandoah & !vm.graal.enabled
+ * @library /test/lib
+ * @run main/othervm TestWrongBarrierEnable
+ */
+
+import java.util.*;
+
+import jdk.test.lib.process.ProcessTools;
+import jdk.test.lib.process.OutputAnalyzer;
+
+public class TestWrongBarrierEnable {
+
+    public static void main(String[] args) throws Exception {
+        String[] concurrent = {
+                "ShenandoahStoreValEnqueueBarrier",
+        };
+        String[] iu = {
+                "ShenandoahSATBBarrier",
+        };
+
+        shouldFailAll("-XX:ShenandoahGCHeuristics=adaptive",   concurrent);
+        shouldFailAll("-XX:ShenandoahGCHeuristics=static",     concurrent);
+        shouldFailAll("-XX:ShenandoahGCHeuristics=compact",    concurrent);
+        shouldFailAll("-XX:ShenandoahGCHeuristics=aggressive", concurrent);
+        shouldFailAll("-XX:ShenandoahGCMode=iu",               iu);
+        shouldPassAll("-XX:ShenandoahGCMode=passive",          concurrent);
+        shouldPassAll("-XX:ShenandoahGCMode=passive",          iu);
+    }
+
+    private static void shouldFailAll(String h, String[] barriers) throws Exception {
+        for (String b : barriers) {
+            ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+                    "-XX:+UnlockDiagnosticVMOptions",
+                    "-XX:+UnlockExperimentalVMOptions",
+                    "-XX:+UseShenandoahGC",
+                    h,
+                    "-XX:+" + b,
+                    "-version"
+            );
+            OutputAnalyzer output = new OutputAnalyzer(pb.start());
+            output.shouldNotHaveExitValue(0);
+            output.shouldContain("GC mode needs ");
+            output.shouldContain("to work correctly");
+        }
+    }
+
+    private static void shouldPassAll(String h, String[] barriers) throws Exception {
+        for (String b : barriers) {
+            ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+                    "-XX:+UnlockDiagnosticVMOptions",
+                    "-XX:+UnlockExperimentalVMOptions",
+                    "-XX:+UseShenandoahGC",
+                    h,
+                    "-XX:+" + b,
+                    "-version"
+            );
+            OutputAnalyzer output = new OutputAnalyzer(pb.start());
+            output.shouldHaveExitValue(0);
+        }
+    }
+
+}