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

runtime/include/dart_debugger_api.h

Index: runtime/include/dart_debugger_api.h
===================================================================
--- runtime/include/dart_debugger_api.h	(revision 18152)
+++ runtime/include/dart_debugger_api.h	(working copy)
@@ -578,4 +578,53 @@
 */
 DART_EXPORT Dart_Isolate Dart_GetIsolate(Dart_IsolateId isolate_id);
 
+
+/**
+ * Returns VM status information. VM status is implemented using a
+ * different status plug-in for each type of status; for example, there
+ * might be an "isolate" plug-in that returns information about the
+ * current isolates.
+ *
+ * To get a list of status types, this function is called with a
+ * status_type parameter of "statustypes". This list is useful when
+ * building a status dashboard.
+ *
+ * \param request A REST-like string, which uses '/' to separate
+ *     parameters. The first parameter is always the status type.
+ *
+ * \return The requested status as a JSON formatted string, with the
+ *     contents defined by the status plug-in. The caller is responsible
+ *     for freeing this string.
+ */
+DART_EXPORT char* Dart_GetVmStatus(const char* request);
+
+
+/**
+ * A VM status callback. Status plug-ins implement and register this
+ * function using Dart_RegisterStatusPlugin. When Dart_GetVMStatus is
+ * called with the plug-in's status type, the callback is invoked to
+ * provide the requested information.
+ *
+ * Note: status requests execute outside of an isolate (which is why
+ * handles aren't used).
+ *
+ * \param parameters an optional string that defines REST-like parameters
+ *     to define what information is requested.
+ *
+ * \return Returns a valid JSON string, allocated from C heap. The caller
+ *     is responsible for releasing this string.
+ */
+typedef char* (*Dart_VmStatusCallback)(const char* parameters);
+
+
+/**
+ * Register a VM status plug-in. The specified status type must not already
+ * have a registered plug-in.
+ *
+ * \return True if the plug-in was registered, or an error describing the
+ *     failure.
+ */
+DART_EXPORT Dart_Handle Dart_RegisterVmStatusPlugin(
+    const char* status_type, Dart_VmStatusCallback callback);

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

I guess I am not clear about why external entities need to register their status
plugins with the VM. Can't this be filtered out in the webserver loop that you
have.

The VM needs to deal only with the stuff that it can provide.

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

It's so other libraries like io can add status. Is there a better place for
these?

+
 #endif  // INCLUDE_DART_DEBUGGER_API_H_