Reapply "Save and restore feedback from JIT."

runtime/include/dart_api.h

 /*
  * Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
  * for details. All rights reserved. Use of this source code is governed by a
  * BSD-style license that can be found in the LICENSE file.
  */
 
 #ifndef RUNTIME_INCLUDE_DART_API_H_
 #define RUNTIME_INCLUDE_DART_API_H_
 
 /** \mainpage Dart Embedding API Reference
@@ skipping 3167 matching lines @@
  */
 DART_EXPORT Dart_Port Dart_ServiceWaitForLoadPort();
 
 
 /*
  * ==============
  * Precompilation
  * ==============
  */
 
+/**
+ * Saves a serialized version of the information collected for use by the
+ * optimizing compiler, such as type feedback and usage counters. When this
+ * information is passed to Dart_Precompile, the AOT compiler may use it to
+ * produce faster and smaller code. The feedback is only used if the JIT that
+ * created it and the AOT compiler consuming it
+ *   - are running the same Dart program
+ *   - are built from the same version of the VM
+ *   - agree on whether type checks and assertions are enabled
+ *
+ * \return Returns an error handler if the VM was built in a mode that does not
+ * support saving JIT feedback.
+ */
+DART_EXPORT Dart_Handle Dart_SaveJITFeedback(uint8_t** buffer,
+                                             intptr_t* buffer_length);
+
 
 typedef struct {
   const char* library_uri;
   const char* class_name;
   const char* function_name;
 } Dart_QualifiedFunctionName;
 
 
 /**
  * Compiles all functions reachable from the provided entry points and marks
  * the isolate to disallow future compilation.
  *
  * \param entry_points A list of functions that may be invoked through the
  * embedding API, e.g. Dart_Invoke/GetField/SetField/New/InvokeClosure.
  *
  * \param reset_fields Controls whether static fields are reset. Fields without
  * an initializer will be set to null, and fields with an initializer will have
  * their initializer run the next time they are accessed.
  *
  * reset_fields is true when we are about to create a precompilated snapshot.
  * Some fields are already been initialized as part of the loading logic, and
  * we want them to be reinitialized in the new process that will load the
  * snapshot. reset_fields is false for --noopt, which will continue running in
  * the same process.
  *
  * \return An error handle if a compilation error or runtime error running const
  * constructors was encountered.
  */
 DART_EXPORT Dart_Handle
-Dart_Precompile(Dart_QualifiedFunctionName entry_points[], bool reset_fields);
+Dart_Precompile(Dart_QualifiedFunctionName entry_points[],
+                bool reset_fields,
+                uint8_t* jit_feedback,
+                intptr_t jit_feedback_length);
 
 
 /**
  *  Creates a precompiled snapshot.
  *   - A root library must have been loaded.
  *   - Dart_Precompile must have been called.
  *
  *  Outputs a vm isolate snapshot, an isolate snapshot, and an assembly file
  *  defining the symbols kInstructionsSnapshot and kDataSnapshot. The assembly
  *  should be compiled as a static or shared library and linked or loaded by the
@@ skipping 74 matching lines @@
  */
 DART_EXPORT bool Dart_IsPrecompiledRuntime();
 
 
 /**
  *  Print a native stack trace. Used for crash handling.
  */
 DART_EXPORT void Dart_DumpNativeStackTrace(void* context);
 
 #endif /* INCLUDE_DART_API_H_ */ /* NOLINT */