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

runtime/vm/debugger.cc

Index: runtime/vm/debugger.cc
===================================================================
--- runtime/vm/debugger.cc	(revision 18152)
+++ runtime/vm/debugger.cc	(working copy)
@@ -4,14 +4,18 @@
 
 #include "vm/debugger.h"
 
+#include <string>
+
 #include "include/dart_api.h"
 
 #include "vm/code_generator.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
+#include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
 #include "vm/flags.h"
 #include "vm/globals.h"
+#include "vm/isolate.h"
 #include "vm/longjump.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
@@ -1734,4 +1738,56 @@
   code_breakpoints_ = bpt;
 }
 
+
+// Global static pointer used to ensure a single instance of the class.
+VmStatusService* VmStatusService::instance_ = NULL;
+
+
+void VmStatusService::InitOnce() {
+  VmStatusService::instance_ = new VmStatusService();
+
+  // Register built-in status plug-ins. RegisterPlugin is not used because
+  // this isn't called within an isolate, and because parameter checking
+  // isn't necessary.
+  VmStatusService::instance_->service_map_["isolate"] = &Isolate::GetStatus;
+
+  // TODO(tball): dynamically load any additional plug-ins.
+}
+
+
+Dart_Handle VmStatusService::RegisterPlugin(
+    const char* status_type, Dart_VmStatusCallback callback) {

[siva, 2013/02/11 19:14:55]

Do you expect multiple threads to register plugins? If yes then this needs to be
thread safe.

+  if (status_type == NULL) {
+    return Api::NewError("status_type not specified");
+  }
+  if (callback == NULL) {
+    return Api::NewError("callback not specified");
+  }
+  VmStatusService::instance_->service_map_[status_type] = callback;
+  return Api::True(Isolate::Current());
+}
+
+
+char* VmStatusService::Dart_GetVmStatus(const char* request) {
+  // Extract service type from beginning of string.
+  char* start = const_cast<char*>(request);
+  if (*start == '/') {
+    start++;
+  }
+  size_t n = 0;
+  while (*(start + n) != '\0' && *(start + n) != '/') {
+    n++;
+  }
+  ASSERT(n != 0);
+  char* status_type = strndup(start, n);
+  ServiceMap* map = &VmStatusService::instance_->service_map_;
+  ServiceMap::iterator itr = map->find(status_type);
+  if (itr == map->end()) {
+    return strdup("");  // No status available for this status type.
+  }
+  Dart_VmStatusCallback callback = itr->second;
+  free(status_type);
+  return (callback)(request);
+}
+
 }  // namespace dart