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

rev 54386 : 8221766: Load-reference barriers for Shenandoah

@@ -44,16 +44,12 @@
 
   FLAG_SET_DEFAULT(ShenandoahGCHeuristics,           "passive");
 
   FLAG_SET_DEFAULT(ShenandoahSATBBarrier,            false);
   FLAG_SET_DEFAULT(ShenandoahKeepAliveBarrier,       false);
-  FLAG_SET_DEFAULT(ShenandoahWriteBarrier,           false);
-  FLAG_SET_DEFAULT(ShenandoahReadBarrier,            false);
   FLAG_SET_DEFAULT(ShenandoahStoreValEnqueueBarrier, false);
-  FLAG_SET_DEFAULT(ShenandoahStoreValReadBarrier,    false);
   FLAG_SET_DEFAULT(ShenandoahCASBarrier,             false);
-  FLAG_SET_DEFAULT(ShenandoahAcmpBarrier,            false);
   FLAG_SET_DEFAULT(ShenandoahCloneBarrier,           false);
 #endif
 
 #ifdef _LP64
   // The optimized ObjArrayChunkedTask takes some bits away from the full 64 addressable

@@ -109,16 +105,12 @@
 #ifdef ASSERT
   // C2 barrier verification is only reliable when all default barriers are enabled
   if (ShenandoahVerifyOptoBarriers &&
           (!FLAG_IS_DEFAULT(ShenandoahSATBBarrier)            ||
            !FLAG_IS_DEFAULT(ShenandoahKeepAliveBarrier)       ||
-           !FLAG_IS_DEFAULT(ShenandoahWriteBarrier)           ||
-           !FLAG_IS_DEFAULT(ShenandoahReadBarrier)            ||
            !FLAG_IS_DEFAULT(ShenandoahStoreValEnqueueBarrier) ||
-           !FLAG_IS_DEFAULT(ShenandoahStoreValReadBarrier)    ||
            !FLAG_IS_DEFAULT(ShenandoahCASBarrier)             ||
-           !FLAG_IS_DEFAULT(ShenandoahAcmpBarrier)            ||
            !FLAG_IS_DEFAULT(ShenandoahCloneBarrier)
           )) {
     warning("Unusual barrier configuration, disabling C2 barrier verification");
     FLAG_SET_DEFAULT(ShenandoahVerifyOptoBarriers, false);
   }

@@ -162,17 +154,10 @@
       warning("Shenandoah does not support AOT at this moment, disabling UseAOT");
     }
     FLAG_SET_DEFAULT(UseAOT, false);
   }
 
-  // JNI fast get field stuff is not currently supported by Shenandoah.
-  // It would introduce another heap memory access for reading the forwarding
-  // pointer, which would have to be guarded by the signal handler machinery.
-  // See:
-  // http://mail.openjdk.java.net/pipermail/hotspot-dev/2018-June/032763.html
-  FLAG_SET_DEFAULT(UseFastJNIAccessors, false);
-
   // TLAB sizing policy makes resizing decisions before each GC cycle. It averages
   // historical data, assigning more recent data the weight according to TLABAllocationWeight.
   // Current default is good for generational collectors that run frequent young GCs.
   // With Shenandoah, GC cycles are much less frequent, so we need we need sizing policy
   // to converge faster over smaller number of resizing decisions.