backport 1748737b99f283f69b4be0910b6623a27d804e68

Author: GoeLin

src/hotspot/share/classfile/resolutionErrors.cpp

@@ -112,14 +112,12 @@ void ResolutionErrorEntry::set_cause_msg(const char* c) {
 
 // The incoming nest host error message is already in the C-Heap.
 void ResolutionErrorEntry::set_nest_host_error(const char* message) {
-  // If a message is already set, free it.
-  if (nest_host_error() != nullptr) {
-    FREE_C_HEAP_ARRAY(char, _nest_host_error);
-  }
+  assert(_nest_host_error == nullptr, "caller should have checked");
   init_nest_host_error(message);
 }
 
 void ResolutionErrorEntry::init_nest_host_error(const char* message) {
+   assert_lock_strong(SystemDictionary_lock);
   _nest_host_error = message;
 }
 

src/hotspot/share/classfile/systemDictionary.cpp

@@ -1889,7 +1889,7 @@ Symbol* SystemDictionary::find_resolution_error(const constantPoolHandle& pool,
 // be updated with the nest host error message.
 void SystemDictionary::add_nest_host_error(const constantPoolHandle& pool,
                                            int which,
-                                           const char* message) {
+                                           const stringStream& message) {
   unsigned int hash = resolution_errors()->compute_hash(pool, which);
   int index = resolution_errors()->hash_to_index(hash);
   {
@@ -1900,14 +1900,19 @@ void SystemDictionary::add_nest_host_error(const constantPoolHandle& pool,
       // constant pool index. In this case resolution succeeded but there's an error in this nest host
       // that we use the table to record.
       assert(pool->resolved_klass_at(which) != nullptr, "klass should be resolved if there is no entry");
-      resolution_errors()->add_entry(index, hash, pool, which, message);
+      resolution_errors()->add_entry(index, hash, pool, which, message.as_string(true /* on C-heap */));
     } else {
       // An existing entry means we had a true resolution failure (LinkageError) with our nest host, but we
       // still want to add the error message for the higher-level access checks to report. We should
       // only reach here under the same error condition, so we can ignore the potential race with setting
-      // the message, and set it again.
-      assert(entry->nest_host_error() == nullptr || strcmp(entry->nest_host_error(), message) == 0, "should be the same message");
-      entry->set_nest_host_error(message);
+      // the message.
+      const char* nhe = entry->nest_host_error();
+      if (nhe == nullptr) {
+        entry->set_nest_host_error(message.as_string(true /* on C-heap */));
+      } else {
+        DEBUG_ONLY(const char* msg = message.base();)
+        assert(strcmp(nhe, msg) == 0, "New message %s, differs from original %s", msg, nhe);
+      }
     }
   }
 }

src/hotspot/share/classfile/systemDictionary.hpp

@@ -289,7 +289,7 @@ class SystemDictionary : AllStatic {
 
   // Record a nest host resolution/validation error
   static void add_nest_host_error(const constantPoolHandle& pool, int which,
-                                  const char* message);
+                                  const stringStream& message);
   static const char* find_nest_host_error(const constantPoolHandle& pool, int which);
 
  private:

src/hotspot/share/oops/instanceKlass.cpp

@@ -280,12 +280,11 @@ InstanceKlass* InstanceKlass::nest_host(TRAPS) {
       ss.print("Nest host resolution of %s with host %s failed: ",
                this->external_name(), target_host_class);
       java_lang_Throwable::print(PENDING_EXCEPTION, &ss);
-      const char* msg = ss.as_string(true /* on C-heap */);
       constantPoolHandle cph(THREAD, constants());
-      SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
+      SystemDictionary::add_nest_host_error(cph, _nest_host_index, ss);
       CLEAR_PENDING_EXCEPTION;
 
-      log_trace(class, nestmates)("%s", msg);
+      log_trace(class, nestmates)("%s", ss.base());
     } else {
       // A valid nest-host is an instance class in the current package that lists this
       // class as a nest member. If any of these conditions are not met the class is
@@ -324,10 +323,9 @@ InstanceKlass* InstanceKlass::nest_host(TRAPS) {
                  k->external_name(),
                  k->class_loader_data()->loader_name_and_id(),
                  error);
-        const char* msg = ss.as_string(true /* on C-heap */);
         constantPoolHandle cph(THREAD, constants());
-        SystemDictionary::add_nest_host_error(cph, _nest_host_index, msg);
-        log_trace(class, nestmates)("%s", msg);
+        SystemDictionary::add_nest_host_error(cph, _nest_host_index, ss);
+        log_trace(class, nestmates)("%s", ss.base());
       }
     }
   } else {