Merge the Merlin heap tracing to top-of-trunk.

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 INCLUDE_DART_API_H_
 #define INCLUDE_DART_API_H_
 
 /** \mainpage Dart Embedding API Reference
  *
  * Dart is a class-based programming language for creating structured
@@ skipping 516 matching lines @@
  *
  * \return Success if the callback was removed.  Otherwise, returns an
  *   error handle.
  */
 DART_EXPORT Dart_Handle Dart_RemoveGcEpilogueCallback(
     Dart_GcEpilogueCallback callback);
 
 // --- Heap Profiler ---
 
 /**
- * A callback invoked by the heap profiler during profiling to write
- * data.
+ * A callback invoked by the VM to write to a specified stream.
+ * Used by the heap profiler and gc trace.
  */
-typedef void (*Dart_HeapProfileWriteCallback)(const void* data,
-                                              intptr_t length,
-                                              void* stream);
+typedef void (*Dart_FileWriteCallback)(const void* data,
+                                       intptr_t length,
+                                       void* stream);
+
+typedef void* (*Dart_FileOpenCallback)(const char* name);
+
+typedef void (*Dart_FileCloseCallback)(void* stream);
+
 
 /**
  * Generates a heap profile.
  *
  * \param callback A function pointer that will be repeatedly invoked
  *   with heap profile data.
  * \param stream A pointer that will be passed to the callback.  This
  *   is a convenient way to provide an open stream to the callback.
  *
  * \return Success if the heap profile is successful.
  */
-DART_EXPORT Dart_Handle Dart_HeapProfile(Dart_HeapProfileWriteCallback callback,
+DART_EXPORT Dart_Handle Dart_HeapProfile(Dart_FileWriteCallback callback,
                                          void* stream);
 
 // --- Initialization and Globals ---
 
 /**
  * Gets the version string for the Dart VM.
  *
  * The version of the Dart VM can be accessed without initializing the VM.
  *
  * \return The version string for the embedded Dart VM.
@@ skipping 2168 matching lines @@
  * \param library A library.
  * \param resolver A native entry resolver.
  *
  * \return A valid handle if the native resolver was set successfully.
  */
 DART_EXPORT Dart_Handle Dart_SetNativeResolver(
     Dart_Handle library,
     Dart_NativeEntryResolver resolver);
 // TODO(turnidge): Rename to Dart_LibrarySetNativeResolver?
 
-// --- Profiling support ----
+// --- Profiling support ---
 
 // External pprof support for gathering and dumping symbolic
 // information that can be used for better profile reports for
 // dynamically generated code.
 DART_EXPORT void Dart_InitPprofSupport();
 DART_EXPORT void Dart_GetPprofSymbolInfo(void** buffer, int* buffer_size);
 
 typedef void (*Dart_FileWriterFunction)(const char* buffer, int64_t num_bytes);
 
 // Support for generating symbol maps for use by the Linux perf tool.
 DART_EXPORT void Dart_InitPerfEventsSupport(Dart_FileWriterFunction function);
 
+// --- Heap tracing support ---
+
+DART_EXPORT void Dart_InitHeapTrace(Dart_FileOpenCallback open_function,

[Ivan Posva, 2012/12/04 16:32:52]

Shouldn't we just register a general open, write and close callback? And then
init heap trace or the other operations with a name?

[cshapiro, 2012/12/04 21:13:33]

Sure, I can do that.  I would like the streams for the heap trace to do I/O
asynchronously.  This might be okay for other kinds of I/O but I am not entirely
certain.

+                                    Dart_FileWriteCallback write_function,
+                                    Dart_FileCloseCallback close_function,
+                                    const char* prefix);
+
 // --- Peers ---
 
 /**
  * The peer field is a lazily allocated field intendend for storage of
  * an uncommonly used values.  Most instances types can have a peer
  * field allocated.  The exceptions are subtypes of Null, num, and
  * bool.
  */
 
 /**
@@ skipping 14 matching lines @@
  *
  * \param object An object.
  * \param peer A value to store in the peer field.
  *
  * \return Returns an error if 'object' is a subtype of Null, num, or
  *   bool.
  */
 DART_EXPORT Dart_Handle Dart_SetPeer(Dart_Handle object, void* peer);
 
 #endif  // INCLUDE_DART_API_H_