8138922: StubCodeDesc constructor publishes partially-constructed objects on StubCodeDesc::_list

Reviewed-by: kvn, coleenp, dholmes

hotspot/src/share/vm/code/codeBlob.cpp

@@ -291,6 +291,9 @@ MethodHandlesAdapterBlob* MethodHandlesAdapterBlob::create(int buffer_size) {
   {
     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
     blob = new (size) MethodHandlesAdapterBlob(size);
+    if (blob == NULL) {
+      vm_exit_out_of_memory(size, OOM_MALLOC_ERROR, "CodeCache: no room for method handle adapter blob");
+    }
   }
   // Track memory usage statistic after releasing CodeCache_lock
   MemoryService::track_code_cache_memory_usage();

hotspot/src/share/vm/prims/methodHandles.cpp

@@ -63,30 +63,21 @@
 bool MethodHandles::_enabled = false; // set true after successful native linkage
 MethodHandlesAdapterBlob* MethodHandles::_adapter_code = NULL;
 
-
 /**
  * Generates method handle adapters. Returns 'false' if memory allocation
  * failed and true otherwise.
  */
-bool MethodHandles::generate_adapters() {
-  if (SystemDictionary::MethodHandle_klass() == NULL) {
-    return true;
-  }
-
+void MethodHandles::generate_adapters() {
+  assert(SystemDictionary::MethodHandle_klass() != NULL, "should be present");
   assert(_adapter_code == NULL, "generate only once");
 
   ResourceMark rm;
   TraceTime timer("MethodHandles adapters generation", TraceStartupTime);
   _adapter_code = MethodHandlesAdapterBlob::create(adapter_code_size);
-  if (_adapter_code == NULL) {
-     return false;
-  }
-
   CodeBuffer code(_adapter_code);
   MethodHandlesAdapterGenerator g(&code);
   g.generate();
   code.log_section_sizes("MethodHandlesAdapterBlob");
-  return true;
 }
 
 //------------------------------------------------------------------------------
@@ -1435,54 +1426,32 @@ static JNINativeMethod MH_methods[] = {
   {CC "invokeExact",               CC "([" OBJ ")" OBJ,                       FN_PTR(MH_invokeExact_UOE)}
 };
 
-/**
- * Helper method to register native methods.
- */
-static bool register_natives(JNIEnv* env, jclass clazz, const JNINativeMethod* methods, jint nMethods) {
-  int status = env->RegisterNatives(clazz, methods, nMethods);
-  if (status != JNI_OK || env->ExceptionOccurred()) {
-    warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
-    env->ExceptionClear();
-    return false;
-  }
-  return true;
-}
-
 /**
  * This one function is exported, used by NativeLookup.
  */
 JVM_ENTRY(void, JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass MHN_class)) {
   assert(!MethodHandles::enabled(), "must not be enabled");
-  bool enable_MH = true;
+  assert(SystemDictionary::MethodHandle_klass() != NULL, "should be present");
 
-  jclass MH_class = NULL;
-  if (SystemDictionary::MethodHandle_klass() == NULL) {
-    enable_MH = false;
-  } else {
-    oop mirror = SystemDictionary::MethodHandle_klass()->java_mirror();
-    MH_class = (jclass) JNIHandles::make_local(env, mirror);
-  }
+  oop mirror = SystemDictionary::MethodHandle_klass()->java_mirror();
+  jclass MH_class = (jclass) JNIHandles::make_local(env, mirror);
 
-  if (enable_MH) {
+  {
     ThreadToNativeFromVM ttnfv(thread);
 
-    if (enable_MH) {
-      enable_MH = register_natives(env, MHN_class, MHN_methods, sizeof(MHN_methods)/sizeof(JNINativeMethod));
-    }
-    if (enable_MH) {
-      enable_MH = register_natives(env, MH_class, MH_methods, sizeof(MH_methods)/sizeof(JNINativeMethod));
-    }
+    int status = env->RegisterNatives(MHN_class, MHN_methods, sizeof(MHN_methods)/sizeof(JNINativeMethod));
+    guarantee(status == JNI_OK && !env->ExceptionOccurred(),
+              "register java.lang.invoke.MethodHandleNative natives");
+
+    status = env->RegisterNatives(MH_class, MH_methods, sizeof(MH_methods)/sizeof(JNINativeMethod));
+    guarantee(status == JNI_OK && !env->ExceptionOccurred(),
+              "register java.lang.invoke.MethodHandle natives");
   }
 
   if (TraceInvokeDynamic) {
     tty->print_cr("MethodHandle support loaded (using LambdaForms)");
   }
 
-  if (enable_MH) {
-    if (MethodHandles::generate_adapters() == false) {
-      THROW_MSG(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for method handle adapters");
-    }
-    MethodHandles::set_enabled(true);
-  }
+  MethodHandles::set_enabled(true);
 }
 JVM_END

hotspot/src/share/vm/prims/methodHandles.hpp

@@ -81,7 +81,7 @@ class MethodHandles: AllStatic {
   static void flush_dependent_nmethods(Handle call_site, Handle target);
 
   // Generate MethodHandles adapters.
-  static bool generate_adapters();
+  static void generate_adapters();
 
   // Called from MethodHandlesAdapterGenerator.
   static address generate_method_handle_interpreter_entry(MacroAssembler* _masm, vmIntrinsics::ID iid);

hotspot/src/share/vm/runtime/init.cpp

@@ -145,6 +145,7 @@ jint init_globals() {
   }
   javaClasses_init();   // must happen after vtable initialization
   stubRoutines_init2(); // note: StubRoutines need 2-phase init
+  MethodHandles::generate_adapters();
   CodeCacheExtensions::complete_step(CodeCacheExtensionsSteps::StubRoutines2);
 
 #if INCLUDE_NMT

hotspot/src/share/vm/runtime/stubCodeGenerator.cpp

@@ -37,7 +37,7 @@
 
 StubCodeDesc* StubCodeDesc::_list = NULL;
 int           StubCodeDesc::_count = 0;
-
+bool          StubCodeDesc::_frozen = false;
 
 StubCodeDesc* StubCodeDesc::desc_for(address pc) {
   StubCodeDesc* p = _list;
@@ -46,20 +46,23 @@ StubCodeDesc* StubCodeDesc::desc_for(address pc) {
   return p;
 }
 
-
 StubCodeDesc* StubCodeDesc::desc_for_index(int index) {
   StubCodeDesc* p = _list;
   while (p != NULL && p->index() != index) p = p->_next;
   return p;
 }
 
-
 const char* StubCodeDesc::name_for(address pc) {
   StubCodeDesc* p = desc_for(pc);
   return p == NULL ? NULL : p->name();
 }
 
 
+void StubCodeDesc::freeze() {
+  assert(!_frozen, "repeated freeze operation");
+  _frozen = true;
+}
+
 void StubCodeDesc::print_on(outputStream* st) const {
   st->print("%s", group());
   st->print("::");
@@ -110,12 +113,10 @@ StubCodeGenerator::~StubCodeGenerator() {
   }
 }
 
-
 void StubCodeGenerator::stub_prolog(StubCodeDesc* cdesc) {
   // default implementation - do nothing
 }
 
-
 void StubCodeGenerator::stub_epilog(StubCodeDesc* cdesc) {
   // default implementation - record the cdesc
   if (_first_stub == NULL)  _first_stub = cdesc;

hotspot/src/share/vm/runtime/stubCodeGenerator.hpp

@@ -28,7 +28,7 @@
 #include "asm/assembler.hpp"
 #include "memory/allocation.hpp"
 
-// All the basic framework for stubcode generation/debugging/printing.
+// All the basic framework for stub code generation/debugging/printing.
 
 
 // A StubCodeDesc describes a piece of generated code (usually stubs).
@@ -37,9 +37,10 @@
 // this may have to change if searching becomes too slow.
 
 class StubCodeDesc: public CHeapObj<mtCode> {
- protected:
+ private:
   static StubCodeDesc* _list;                  // the list of all descriptors
   static int           _count;                 // length of list
+  static bool          _frozen;                // determines whether _list modifications are allowed
 
   StubCodeDesc*        _next;                  // the next element in the linked list
   const char*          _group;                 // the group to which the stub code belongs
@@ -68,6 +69,7 @@ class StubCodeDesc: public CHeapObj<mtCode> {
   static const char*   name_for(address pc);     // returns the name of the code containing pc or NULL
 
   StubCodeDesc(const char* group, const char* name, address begin, address end = NULL) {
+    assert(!_frozen, "no modifications allowed");
     assert(name != NULL, "no name specified");
     _next           = _list;
     _group          = group;
@@ -78,6 +80,8 @@ class StubCodeDesc: public CHeapObj<mtCode> {
     _list           = this;
   };
 
+  static void freeze();
+
   const char* group() const                      { return _group; }
   const char* name() const                       { return _name; }
   int         index() const                      { return _index; }
@@ -117,7 +121,7 @@ class StubCodeGenerator: public StackObj {
 // later via an address pointing into it.
 
 class StubCodeMark: public StackObj {
- protected:
+ private:
   StubCodeGenerator* _cgen;
   StubCodeDesc*      _cdesc;
 

hotspot/src/share/vm/runtime/thread.cpp

@@ -3600,6 +3600,9 @@ jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
     vm_exit_during_initialization("Failed to initialize tracing backend");
   }
 
+  // No more stub generation allowed after that point.
+  StubCodeDesc::freeze();
+
   // Set flag that basic initialization has completed. Used by exceptions and various
   // debug stuff, that does not work until all basic classes have been initialized.
   set_init_completed();