# HG changeset patch
# User vlivanov
# Date 1457948144 -10800
# Node ID e791e26c8f1be1b0ca22b011bbd29df68e4b889d
# Parent  4ae7b86df4ae76497eacf1b0b688e186b1ae3c4e
8139247: Improper locking of MethodData::_extra_data_lock
Reviewed-by: dholmes, roland, dcubed

diff -r 4ae7b86df4ae -r e791e26c8f1b hotspot/src/share/vm/ci/ciMethodData.cpp
--- a/hotspot/src/share/vm/ci/ciMethodData.cpp	Fri Mar 11 21:02:09 2016 +0100
+++ b/hotspot/src/share/vm/ci/ciMethodData.cpp	Mon Mar 14 12:35:44 2016 +0300
@@ -81,7 +81,7 @@
 void ciMethodData::load_extra_data() {
   MethodData* mdo = get_MethodData();
 
-  MutexLocker(mdo->extra_data_lock());
+  MutexLocker ml(mdo->extra_data_lock());
 
   // speculative trap entries also hold a pointer to a Method so need to be translated
   DataLayout* dp_src  = mdo->extra_data_base();
@@ -103,16 +103,13 @@
 
     switch(tag) {
     case DataLayout::speculative_trap_data_tag: {
-      ciSpeculativeTrapData* data_dst = new ciSpeculativeTrapData(dp_dst);
-      SpeculativeTrapData* data_src = new SpeculativeTrapData(dp_src);
-
-      data_dst->translate_from(data_src);
+      ciSpeculativeTrapData data_dst(dp_dst);
+      SpeculativeTrapData   data_src(dp_src);
 
-#ifdef ASSERT
-      SpeculativeTrapData* data_src2 = new SpeculativeTrapData(dp_src);
-      assert(data_src2->method() == data_src->method() && data_src2->bci() == data_src->bci(), "entries changed while translating");
-#endif
-
+      { // During translation a safepoint can happen or VM lock can be taken (e.g., Compile_lock).
+        MutexUnlocker ml(mdo->extra_data_lock());
+        data_dst.translate_from(&data_src);
+      }
       break;
     }
     case DataLayout::bit_data_tag:
@@ -120,9 +117,11 @@
     case DataLayout::no_tag:
     case DataLayout::arg_info_data_tag:
       // An empty slot or ArgInfoData entry marks the end of the trap data
-      return;
+      {
+        return; // Need a block to avoid SS compiler bug
+      }
     default:
-      fatal("bad tag = %d", dp_dst->tag());
+      fatal("bad tag = %d", tag);
     }
   }
 }