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

runtime/bin/main.cc

Index: runtime/bin/main.cc
===================================================================
--- runtime/bin/main.cc	(revision 18477)
+++ runtime/bin/main.cc	(working copy)
@@ -20,6 +20,7 @@
 #include "bin/log.h"
 #include "bin/platform.h"
 #include "bin/process.h"
+#include "bin/vmstats_impl.h"
 #include "platform/globals.h"
 
 // snapshot_buffer points to a snapshot if we link in a snapshot otherwise
@@ -47,6 +48,9 @@
 static const char* debug_ip = DEFAULT_DEBUG_IP;
 static int debug_port = 0;
 
+// Global state that defines the VmStats web server port and root directory.
+static int vmstats_port = 0;
+static const char* vmstats_root = NULL;
 
 // Value of the --package-root flag.
 // (This pointer points into an argv buffer and does not need to be
@@ -164,6 +168,31 @@
 }
 
 
+static bool ProcessVmStatsOption(const char* port) {
+  ASSERT(port != NULL);
+  if (*port == '\0') {
+    vmstats_port = -1;  // Dynamically assigned port number.
+  } else {
+    if ((*port == '=') || (*port == ':')) {
+      vmstats_port = atoi(port + 1);
+    }
+  }
+  if (vmstats_port == 0) {
+    Log::PrintErr("unrecognized --stats option syntax. "
+                    "Use --stats[:<port number>]\n");
+    return false;
+  }
+  return true;
+}
+
+
+static bool ProcessVmStatsRootOption(const char* arg) {
+  ASSERT(arg != NULL);
+  vmstats_root = arg;
+  return true;
+}
+
+
 static bool ProcessGenScriptSnapshotOption(const char* filename) {
   if (filename != NULL && strlen(filename) != 0) {
     // Ensure that are already running using a full snapshot.
@@ -207,6 +236,8 @@
   { "--debug", ProcessDebugOption },
   { "--use-script-snapshot=", ProcessUseScriptSnapshotOption },
   { "--generate-script-snapshot=", ProcessGenScriptSnapshotOption },
+  { "--stats-root=", ProcessVmStatsRootOption },
+  { "--stats", ProcessVmStatsOption },
   { NULL, NULL }
 };
 
@@ -488,6 +519,7 @@
     return false;
   }
   Dart_ExitScope();
+  dart::VmStats::AddIsolate(reinterpret_cast<IsolateData*>(data), isolate);
   return true;
 }
 
@@ -550,6 +582,10 @@
 "--generate-script-snapshot=<file_name>\n"
 "  loads Dart script and generates a snapshot in the specified file\n"
 "\n"
+"--stats[:<port number>]\n"
+"  enables VM stats service and listens on specified port for HTTP requests\n"
+"  (default port number is dynamically assigned)\n"
+"\n"

[siva, 2013/02/15 05:59:10]

Should we also list help for the '--stats-root' option here.

[Tom Ball, 2013/02/16 00:57:19]

Done.

 "The following options are only used for VM development and may\n"
 "be changed in any future version:\n");
     const char* print_flags = "--print_flags";
@@ -627,6 +663,7 @@
 
 static void ShutdownIsolate(void* callback_data) {
   IsolateData* isolate_data = reinterpret_cast<IsolateData*>(callback_data);
+  dart::VmStats::RemoveIsolate(isolate_data);
   EventHandler* handler = isolate_data->event_handler;
   if (handler != NULL) handler->Shutdown();
   delete isolate_data;
@@ -713,6 +750,10 @@
 
   Dart_EnterScope();
 
+  if (vmstats_port > 0) {

[siva, 2013/02/15 05:59:10]

What about the case when vmstats_port is -1 ?

[Tom Ball, 2013/02/16 00:57:19]

Good catch. It turns out 0 is the official dynamic port, not -1 (Linux will take
either, but it's probably not cross-platform). I changed it so -1 indicates "no
port specified", and 0 means dynamic port, and updated this test.

+    dart::VmStats::Start(vmstats_port, vmstats_root);
+  }
+
   if (generate_script_snapshot) {
     // First create a snapshot.
     Dart_Handle result;
@@ -773,6 +814,7 @@
   }
 
   Dart_ExitScope();
+  dart::VmStats::Stop();
   // Shutdown the isolate.
   Dart_ShutdownIsolate();
   // Terminate process exit-code handler.