jdk-sandbox: comparison hotspot/src/share/vm/prims/jvmtiRedefineClasses.cpp

equal deleted inserted replaced

-:c82e388e17c5
+:5c343868d071
 constantPoolHandle old_cp(THREAD, the_class->constants());
 constantPoolHandle scratch_cp(THREAD, scratch_class->constants());
 // Constant pools are not easily reused so we allocate a new one
 // each time.
+// merge_cp is created unsafe for concurrent GC processing.  It
+// should be marked safe before discarding it because, even if
+// garbage.  If it crosses a card boundary, it may be scanned
+// in order to find the start of the first complete object on the card.
 constantPoolHandle merge_cp(THREAD,
-oopFactory::new_constantPool(merge_cp_length, THREAD));
+oopFactory::new_constantPool(merge_cp_length,
+methodOopDesc::IsUnsafeConc,
+THREAD));
 int orig_length = old_cp->orig_length();
 if (orig_length == 0) {
 // This old_cp is an actual original constant pool. We save
 // the original length in the merged constant pool so that
 // merge_constant_pools() can be more efficient. If a constant
 // constant pool has not gone through link resolution nor have
 // the new class bytecodes gone through constant pool cache
 // rewriting so we can't use the old constant pool with the new
 // class.
+merge_cp()->set_is_conc_safe(true);
 merge_cp = constantPoolHandle();  // toss the merged constant pool
 } else if (old_cp->length() < scratch_cp->length()) {
 // The old constant pool has fewer entries than the new constant
 // pool and the index map is empty. This means the new constant
 // pool is a superset of the old constant pool. However, the old
 // class bytecodes have already gone through constant pool cache
 // rewriting so we can't use the new constant pool with the old
 // class.
+merge_cp()->set_is_conc_safe(true);
 merge_cp = constantPoolHandle();  // toss the merged constant pool
 } else {
 // The old constant pool has more entries than the new constant
 // pool and the index map is empty. This means that both the old
 // and merged constant pools are supersets of the new constant
 // merged constant pool; the previous new constant pool will
 // get GCed.
 set_new_constant_pool(scratch_class, merge_cp, merge_cp_length, true,
 THREAD);
 // drop local ref to the merged constant pool
+merge_cp()->set_is_conc_safe(true);
 merge_cp = constantPoolHandle();
 }
 } else {
 if (RC_TRACE_ENABLED(0x00040000)) {
 // don't want to loop unless we are tracing
 // merged constant pool so now the rewritten bytecodes have
 // valid references; the previous new constant pool will get
 // GCed.
 set_new_constant_pool(scratch_class, merge_cp, merge_cp_length, true,
 THREAD);
-}
+merge_cp()->set_is_conc_safe(true);
+}
+assert(old_cp()->is_conc_safe(), "Just checking");
+assert(scratch_cp()->is_conc_safe(), "Just checking");
 return JVMTI_ERROR_NONE;
 } // end merge_cp_and_rewrite()
 if (shrink) {
 // scratch_cp is a merged constant pool and has enough space for a
 // worst case merge situation. We want to associate the minimum
 // sized constant pool with the klass to save space.
 constantPoolHandle smaller_cp(THREAD,
-oopFactory::new_constantPool(scratch_cp_length, THREAD));
+oopFactory::new_constantPool(scratch_cp_length,
+methodOopDesc::IsUnsafeConc,
+THREAD));
 // preserve orig_length() value in the smaller copy
 int orig_length = scratch_cp->orig_length();
 assert(orig_length != 0, "sanity check");
 smaller_cp->set_orig_length(orig_length);
 scratch_cp->copy_cp_to(1, scratch_cp_length - 1, smaller_cp, 1, THREAD);
 scratch_cp = smaller_cp;
+smaller_cp()->set_is_conc_safe(true);
 }
 // attach new constant pool to klass
 scratch_cp->set_pool_holder(scratch_class());
 } // end for each local variable table entry
 } // end if there are local variable table entries
 rewrite_cp_refs_in_stack_map_table(method, THREAD);
 } // end for each method
+assert(scratch_cp()->is_conc_safe(), "Just checking");
 } // end set_new_constant_pool()
 // Unevolving classes may point to methods of the_class directly
 // from their constant pool caches, itables, and/or vtables. We

changeset 1894	5c343868d071
parent 1	489c9b5090e2
child 2131	98f9cef66a34
child 2138	a88fa6fb3834
child 2105	347008ce7984