Initial prototype of vmstats support, based on Dart VM Stats draft design doc.

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
===================================================================
--- runtime/vm/isolate.cc	(revision 18152)
+++ runtime/vm/isolate.cc	(working copy)
@@ -4,6 +4,8 @@
 
 #include "vm/isolate.h"
 
+#include <sstream>
+
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "lib/mirrors.h"
@@ -627,4 +629,40 @@
   }
 }
 
+
+char* Isolate::GetStatus(const char* request) {
+  char* p = const_cast<char*>(request);
+  const char* service_type = "/isolate/";
+  ASSERT(strncmp(p, service_type, strlen(service_type)) == 0);
+  p += strlen(service_type);
+
+  // Extract isolate handle.
+  int64_t addr;
+  OS::StringToInt64(p, &addr);
+  Isolate* isolate = reinterpret_cast<Isolate*>(addr);
+  Heap* heap = isolate->heap();
+
+  std::ostringstream stream;
+  stream << '{' << std::endl;
+  stream << "  \"name\": \"" << isolate->name() << "\"," << std::endl;
+  stream << "  \"port\": " << isolate->main_port() << ',' << std::endl;
+  stream << "  \"starttime\": " << (isolate->start_time() / 1000)
+      << ',' << std::endl;
+  stream << "  \"stacklimit\": " << isolate->saved_stack_limit()
+      << ',' << std::endl;
+  stream << "  \"newspace\": {" << std::endl;
+  stream << "    \"used\": " <<
+      heap->Used(Heap::kNew) / KB << ',' << std::endl;
+  stream << "    \"capacity\": " <<
+      heap->Capacity(Heap::kNew) / KB << std::endl;
+  stream << "  }," << std::endl;
+  stream << "  \"oldspace\": {" << std::endl;
+  stream << "    \"used\": " <<
+      heap->Used(Heap::kOld) / KB << ',' << std::endl;
+  stream << "    \"capacity\": " <<
+      heap->Capacity(Heap::kOld) / KB << std::endl;
+  stream << "  }" << std::endl << "}";

[siva, 2013/02/09 01:00:57]

Can this whole sequence be constructed using OS::SNPrint instead of this C++
sstream stuff. We have tried to avoid this sstream stuff in the VM also (trying
to minimize porting surprises).

[Tom Ball, 2013/02/14 23:45:16]

Done.

+  return strdup(stream.str().c_str());
+}
+
 }  // namespace dart