[futex] Allow debugger to break in the middle of a futexWait

src/debug/debug.cc

Index: src/debug/debug.cc
diff --git a/src/debug/debug.cc b/src/debug/debug.cc
index 99036d71e7e7c6df559e192591ff1d36598e35ef..50b7afc4131d90632e576aeb2b7254e1162e3773 100644
--- a/src/debug/debug.cc
+++ b/src/debug/debug.cc
@@ -2276,9 +2276,17 @@ void Debug::HandleDebugBreak() {
     DCHECK(!it.done());
     Object* fun = it.frame()->function();
     if (fun && fun->IsJSFunction()) {
+      HandleScope scope(isolate_);
       // Don't stop in builtin functions.
-      if (!JSFunction::cast(fun)->IsSubjectToDebugging()) return;
-      GlobalObject* global = JSFunction::cast(fun)->context()->global_object();
+      Handle<JSFunction> jsfun(JSFunction::cast(fun));

[Yang, 2015/08/27 06:27:25]

I think it might be cleaner to just pass in an optional parameter from
FutexEmulation::Wait through Execution::HandleInterrupts to here, stating that
the interrupt comes from futex wait.

[binji, 2015/08/31 21:25:18]

Done.

+      if (!jsfun->IsSubjectToDebugging()) {
+        // Make an exception for futexWait.
+        Handle<String> name(String::cast(jsfun->shared()->name()));
+        if (!String::Equals(name, isolate_->factory()->futexWait_string())) {
+          return;
+        }
+      }
+      GlobalObject* global = jsfun->context()->global_object();
       // Don't stop in debugger functions.
       if (IsDebugGlobal(global)) return;
     }