Provide stdout and stderr output in the Observatory debugger.

runtime/vm/service.cc

Index: runtime/vm/service.cc
diff --git a/runtime/vm/service.cc b/runtime/vm/service.cc
index 4cbc5ddba46f142d49aa4c71cb4551b87d1c3ebb..0590c1589f84d62858bda9f3b93d029612ebad69 100644
--- a/runtime/vm/service.cc
+++ b/runtime/vm/service.cc
@@ -5,6 +5,7 @@
 #include "vm/service.h"
 
 #include "include/dart_api.h"
+#include "include/dart_native_api.h"
 #include "platform/globals.h"
 
 #include "vm/compiler.h"
@@ -74,32 +75,50 @@ EmbedderServiceHandler* Service::root_service_handler_head_ = NULL;
 struct ServiceMethodDescriptor;
 ServiceMethodDescriptor* FindMethod(const char* method_name);
 
-// TODO(turnidge): Build a general framework later.  For now, we have
-// a small set of well-known streams.
+
+// These are the set of streams known to the core VM.
+const char* const Service::kIsolateStreamId = "Isolate";
+const char* const Service::kDebugStreamId = "Debug";
+const char* const Service::kGCStreamId = "GC";
+const char* const Service::kEchoStreamId = "_Echo";
+const char* const Service::kGraphStreamId = "_Graph";

[Cutch, 2015/07/13 14:10:29]

Would be nice if we had an array of streams (with the name and the "needs
events" flag being in a  structure together. Then, ListenStream and CancelStream
could be refactored to just loop over data.

[turnidge, 2015/07/13 22:50:36]

Done.

+
+
 bool Service::needs_isolate_events_ = false;
 bool Service::needs_debug_events_ = false;
 bool Service::needs_gc_events_ = false;
 bool Service::needs_echo_events_ = false;
 bool Service::needs_graph_events_ = false;
 
-void Service::ListenStream(const char* stream_id) {
+// Support for streams defined in embedders.
+Dart_ServiceStreamListenCallback Service::stream_listen_callback_ = NULL;
+Dart_ServiceStreamCancelCallback Service::stream_cancel_callback_ = NULL;
+
+
+bool Service::ListenStream(const char* stream_id) {
   if (FLAG_trace_service) {
     OS::Print("vm-service: starting stream '%s'\n",
               stream_id);
   }
-  if (strcmp(stream_id, "Isolate") == 0) {
+  if (strcmp(stream_id, kIsolateStreamId) == 0) {
     needs_isolate_events_ = true;
-  } else if (strcmp(stream_id, "Debug") == 0) {
+    return true;
+  } else if (strcmp(stream_id, kDebugStreamId) == 0) {
     needs_debug_events_ = true;
-  } else if (strcmp(stream_id, "GC") == 0) {
+    return true;
+  } else if (strcmp(stream_id, kGCStreamId) == 0) {
     needs_gc_events_ = true;
-  } else if (strcmp(stream_id, "_Echo") == 0) {
+    return true;
+  } else if (strcmp(stream_id, kEchoStreamId) == 0) {
     needs_echo_events_ = true;
-  } else if (strcmp(stream_id, "_Graph") == 0) {
+    return true;
+  } else if (strcmp(stream_id, kGraphStreamId) == 0) {
     needs_graph_events_ = true;
-  } else {
-    UNREACHABLE();
+    return true;
+  } else if (stream_listen_callback_) {
+    return (*stream_listen_callback_)(stream_id);
   }
+  return false;
 }
 
 void Service::CancelStream(const char* stream_id) {
@@ -107,18 +126,18 @@ void Service::CancelStream(const char* stream_id) {
     OS::Print("vm-service: stopping stream '%s'\n",
               stream_id);
   }
-  if (strcmp(stream_id, "Isolate") == 0) {
+  if (strcmp(stream_id, kIsolateStreamId) == 0) {
     needs_isolate_events_ = false;
-  } else if (strcmp(stream_id, "Debug") == 0) {
+  } else if (strcmp(stream_id, kDebugStreamId) == 0) {
     needs_debug_events_ = false;
-  } else if (strcmp(stream_id, "GC") == 0) {
+  } else if (strcmp(stream_id, kGCStreamId) == 0) {
     needs_gc_events_ = false;
-  } else if (strcmp(stream_id, "_Echo") == 0) {
+  } else if (strcmp(stream_id, kEchoStreamId) == 0) {
     needs_echo_events_ = false;
-  } else if (strcmp(stream_id, "_Graph") == 0) {
+  } else if (strcmp(stream_id, kGraphStreamId) == 0) {
     needs_graph_events_ = false;
-  } else {
-    UNREACHABLE();
+  } else if (stream_cancel_callback_) {
+    return (*stream_cancel_callback_)(stream_id);
   }
 }
 
@@ -578,6 +597,7 @@ void Service::SendEvent(const char* stream_id,
 }
 
 
+// TODO(turnidge): Rewrite this method to use Post_CObject instead.
 void Service::SendEventWithData(const char* stream_id,
                                 const char* event_type,
                                 const String& meta,
@@ -613,6 +633,9 @@ void Service::HandleEvent(ServiceEvent* event) {
   if (ServiceIsolate::IsServiceIsolateDescendant(event->isolate())) {
     return;
   }
+  if (!ServiceIsolate::IsRunning()) {
+    return;
+  }
   JSONStream js;
   const char* stream_id = event->stream_id();
   ASSERT(stream_id != NULL);
@@ -621,9 +644,35 @@ void Service::HandleEvent(ServiceEvent* event) {
     jsobj.AddProperty("event", event);
     jsobj.AddProperty("streamId", stream_id);
   }
-  const String& message = String::Handle(String::New(js.ToCString()));
-  SendEvent(stream_id, ServiceEvent::EventTypeToCString(event->type()),
-            message);
+
+  // Message is of the format [<stream id>, <json string>].
+  //
+  // Build the event message in the C heap to avoid dart heap
+  // allocation.  This method can be called while we have acquired a
+  // direct pointer to typed data, so we can't allocate here.
+  Dart_CObject list_cobj;
+  Dart_CObject* list_values[2];
+  list_cobj.type = Dart_CObject_kArray;
+  list_cobj.value.as_array.length = 2;
+  list_cobj.value.as_array.values = list_values;
+
+  Dart_CObject stream_id_cobj;
+  stream_id_cobj.type = Dart_CObject_kString;
+  stream_id_cobj.value.as_string = const_cast<char*>(stream_id);
+  list_values[0] = &stream_id_cobj;
+
+  Dart_CObject json_cobj;
+  json_cobj.type = Dart_CObject_kString;
+  json_cobj.value.as_string = const_cast<char*>(js.ToCString());
+  list_values[1] = &json_cobj;
+
+  if (FLAG_trace_service) {
+    OS::Print(
+        "vm-service: Pushing event of type %s to stream %s\n",
+        event->KindAsCString(), stream_id);
+  }
+
+  Dart_PostCObject(ServiceIsolate::Port(), &list_cobj);
 }
 
 
@@ -747,6 +796,14 @@ void Service::RegisterRootEmbedderCallback(
 }
 
 
+void Service::SetEmbedderStreamCallbacks(
+    Dart_ServiceStreamListenCallback listen_callback,
+    Dart_ServiceStreamCancelCallback cancel_callback) {
+  stream_listen_callback_ = listen_callback;
+  stream_cancel_callback_ = cancel_callback;
+}
+
+
 EmbedderServiceHandler* Service::FindRootEmbedderHandler(
     const char* name) {
   EmbedderServiceHandler* current = root_service_handler_head_;
@@ -830,11 +887,11 @@ void Service::SendEchoEvent(Isolate* isolate, const char* text) {
         event.AddProperty("text", text);
       }
     }
-    jsobj.AddProperty("streamId", "_Echo");
+    jsobj.AddProperty("streamId", kEchoStreamId);
   }
   const String& message = String::Handle(String::New(js.ToCString()));
   uint8_t data[] = {0, 128, 255};
-  SendEventWithData("_Echo", "_Echo", message, data, sizeof(data));
+  SendEventWithData(kEchoStreamId, "_Echo", message, data, sizeof(data));
 }
 
 
@@ -2349,7 +2406,7 @@ void Service::SendGraphEvent(Isolate* isolate) {
         event.AddProperty("chunkCount", num_chunks);
         event.AddProperty("nodeCount", node_count);
       }
-      jsobj.AddProperty("streamId", "_Graph");
+      jsobj.AddProperty("streamId", kGraphStreamId);
     }
 
     const String& message = String::Handle(String::New(js.ToCString()));
@@ -2359,7 +2416,8 @@ void Service::SendGraphEvent(Isolate* isolate) {
         ? stream.bytes_written() - (i * kChunkSize)
         : kChunkSize;
 
-    SendEventWithData("_Graph", "_Graph", message, chunk_start, chunk_size);
+    SendEventWithData(kGraphStreamId, "_Graph", message,
+                      chunk_start, chunk_size);
   }
 }
 
@@ -2374,6 +2432,22 @@ void Service::SendInspectEvent(Isolate* isolate, const Object& inspectee) {
 }
 
 
+void Service::SendEmbedderEvent(Isolate* isolate,
+                                const char* stream_id,
+                                const char* event_kind,
+                                const uint8_t* bytes,
+                                intptr_t bytes_len) {
+  if (!Service::NeedsDebugEvents()) {
+    return;
+  }
+  ServiceEvent event(isolate, ServiceEvent::kEmbedder);
+  event.set_embedder_kind(event_kind);
+  event.set_embedder_stream_id(stream_id);
+  event.set_bytes(bytes, bytes_len);
+  Service::HandleEvent(&event);
+}
+
+
 class ContainsAddressVisitor : public FindObjectVisitor {
  public:
   ContainsAddressVisitor(Isolate* isolate, uword addr)