Give isolates names to be used during debugging.

runtime/bin/main.cc

Index: runtime/bin/main.cc
===================================================================
--- runtime/bin/main.cc	(revision 3366)
+++ runtime/bin/main.cc	(working copy)
@@ -260,8 +260,10 @@
 }
 
 
-static bool CreateIsolateAndSetup(void* data, char** error) {
-  Dart_Isolate isolate = Dart_CreateIsolate(snapshot_buffer, data, error);
+static bool CreateIsolateAndSetup(const char* name_prefix,
+                                  void* data, char** error) {
+  Dart_Isolate isolate =
+      Dart_CreateIsolate(name_prefix, snapshot_buffer, data, error);
   if (isolate == NULL) {
     return false;
   }
@@ -308,7 +310,7 @@
   Dart_Handle result;
 
   // First create an isolate and load up the specified script in it.
-  if (!CreateIsolateAndSetup(NULL, &error)) {
+  if (!CreateIsolateAndSetup(NULL, NULL, &error)) {
     fprintf(stderr, "%s\n", error);
     free(canonical_script_name);
     free(error);
@@ -359,6 +361,22 @@
 }
 
 
+char* BuildIsolateName(const char* script_name,
+                       const char* func_name) {
+  // Skip past any slashes in the script name.
+  const char* last_slash = strrchr(script_name, '/');
+  if (last_slash != NULL) {
+    script_name = last_slash + 1;
+  }

[siva, 2012/01/18 06:26:03]

Would skipping past slashes cause the name to be non unique?

[turnidge, 2012/01/18 21:29:21]

Yes and no.  If there are two dart scripts with the same file name but different
paths, then the name prefixes will be the same for both of them.  If we were to
include the full path of the script, it would make the name awkwardly long, so I
was trying to strike a balance of providing a prefix that would be usually
unique but still easy to read.

The name prefix here will get a number appended to it inside of isolate.cc, so
in the end then name will be unique regardless of the name prefix generated by
this code.

+
+  const char* kFormat = "%s/%s";
+  intptr_t len = strlen(script_name) + strlen(func_name) + 2;
+  char* buffer = new char[len];

[siva, 2012/01/18 06:26:03]

ASSERT(buffer != NULL);

[turnidge, 2012/01/18 21:29:21]

Done.

+  snprintf(buffer, len, kFormat, script_name, func_name);
+  return buffer;
+}
+
+
 int main(int argc, char** argv) {
   char* script_name;
   CommandLineOptions vm_options(argc);
@@ -405,15 +423,18 @@
   // Call CreateIsolateAndSetup which creates an isolate and loads up
   // the specified application script.
   char* error = NULL;
-  if (!CreateIsolateAndSetup(NULL, &error)) {
+  char* isolate_name = BuildIsolateName(canonical_script_name, "main");
+  if (!CreateIsolateAndSetup(isolate_name, NULL, &error)) {
     fprintf(stderr, "%s\n", error);
     free(canonical_script_name);
     free(error);
     free(script_snapshot_buffer);
+    delete [] isolate_name;
     return 255;  // Indicates we encountered an error.
   }
+  free(script_snapshot_buffer);  // Don't need it anymore.
+  delete [] isolate_name;
 
-  free(script_snapshot_buffer);  // Don't need it anymore.
   Dart_Isolate isolate = Dart_CurrentIsolate();
   ASSERT(isolate != NULL);
   Dart_Handle result;
@@ -440,7 +461,6 @@
     free(canonical_script_name);
     return 255;  // Indicates we encountered an error.
   }
-
   // Lookup the library of the main script.
   Dart_Handle script_url = Dart_NewString(canonical_script_name);
   Dart_Handle library = Dart_LookupLibrary(script_url);