Heartbeat implementation of dart:mirrors.

runtime/vm/code_generator.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/code_generator.h"
 
 #include "vm/code_index_table.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
 #include "vm/exceptions.h"
 #include "vm/ic_data.h"
 #include "vm/object_store.h"
+#include "vm/message.h"
 #include "vm/resolver.h"
 #include "vm/runtime_entry.h"
 #include "vm/stack_frame.h"
 #include "vm/verifier.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, inline_cache, true, "enable inline caches");
 DEFINE_FLAG(bool, trace_deopt, false, "Trace deoptimization");
 DEFINE_FLAG(bool, trace_ic, false, "trace IC handling");
@@ skipping 843 matching lines @@
 
 
 DEFINE_RUNTIME_ENTRY(ClosureArgumentMismatch, 0) {
   ASSERT(arguments.Count() ==
          kClosureArgumentMismatchRuntimeEntry.argument_count());
   GrowableArray<const Object*> args;
   Exceptions::ThrowByType(Exceptions::kClosureArgumentMismatch, args);
 }
 
 
+static RawInstance* DeserializeMessage(void* data) {
+  // Create a snapshot object using the buffer.
+  const Snapshot* snapshot = Snapshot::SetupFromBuffer(data);
+  ASSERT(snapshot->IsMessageSnapshot());
+
+  // Read object back from the snapshot.
+  SnapshotReader reader(snapshot, Isolate::Current());
+  Instance& instance = Instance::Handle();
+  instance ^= reader.ReadObject();

[siva, 2012/02/18 01:25:55]

Ditto comment about any object being send in these OOB messages.

+  return instance.raw();
+}

[siva, 2012/02/18 01:25:55]

This function is there in dart_api_impl.cc as well probably needs to be
refactored into snapshot.h or something.

[turnidge, 2012/03/07 20:00:14]

Agreed.  As the next part of the ThreadPool stuff I am working on, I intend to
consolidate the duplicated message handling code.  Not sure if it makes sense to
do it beforehand, since it will all move anyways.

+
+
+
 DEFINE_RUNTIME_ENTRY(StackOverflow, 0) {
   ASSERT(arguments.Count() ==
          kStackOverflowRuntimeEntry.argument_count());
   uword stack_pos = reinterpret_cast<uword>(&arguments);
 
   // If an interrupt happens at the same time as a stack overflow, we
   // process the stack overflow first.
   if (stack_pos < isolate->saved_stack_limit()) {
     // Use the preallocated stack overflow exception to avoid calling
     // into dart code.
     const Instance& exception =
         Instance::Handle(isolate->object_store()->stack_overflow());
     Exceptions::Throw(exception);
     UNREACHABLE();
   }
 
   uword interrupt_bits = isolate->GetAndClearInterrupts();
   if (interrupt_bits & Isolate::kMessageInterrupt) {
-    // UNIMPLEMENTED();
+    while (true) {
+      Message* message =
+          isolate->message_handler()->queue()->DequeueNoWaitWithPriority(
+              Message::kOOBPriority);

[siva, 2012/02/18 01:25:55]

Can one do a DNS style attack here just bombarding the isolate with OOB
messages?

[turnidge, 2012/03/07 20:00:14]

You can only send OOB messages when you can already send normal messages.  So we
might argue that a hostile isolate can already cause some troubles.  Now the
fact that these are OOB maybe makes things worse though.

What do you think?

+      if (message == NULL) {
+        // No more OOB messages to handle.
+        break;
+      }
+      const Instance& msg =
+          Instance::Handle(DeserializeMessage(message->data()));
+      // For now the only OOB messages are Mirrors messages.
+      const Object& result = Object::Handle(
+          DartLibraryCalls::HandleMirrorsMessage(
+              message->dest_port(), message->reply_port(), msg));
+      delete message;
+      if (result.IsError()) {
+        // TODO(turnidge): Propagating the error is probably wrong here.
+        Exceptions::PropagateError(result);
+      }
+      ASSERT(result.IsNull());
+    }
   }
   if (interrupt_bits & Isolate::kApiInterrupt) {
     Dart_IsolateInterruptCallback callback = isolate->InterruptCallback();
     if (callback) {
       if ((*callback)()) {
         return;
       } else {
         // TODO(turnidge): Unwind the stack.
         UNIMPLEMENTED();
       }
@@ skipping 217 matching lines @@
       }
     }
   }
   // The cache is null terminated, therefore the loop above should never
   // terminate by itself.
   UNREACHABLE();
   return Code::null();
 }
 
 }  // namespace dart