Allow embedders to provide custom message delivery for an isolate.

runtime/vm/port.h

Index: runtime/vm/port.h
===================================================================
--- runtime/vm/port.h	(revision 513)
+++ runtime/vm/port.h	(working copy)
@@ -5,88 +5,37 @@
 #ifndef VM_PORT_H_
 #define VM_PORT_H_
 
+#include "include/dart_api.h"
 #include "vm/allocation.h"
 #include "vm/globals.h"
-#include "vm/growable_array.h"
-#include "vm/isolate.h"
-#include "vm/thread.h"
 
 namespace dart {
 
-class PortMessage {
- public:
-  // A new message to be sent between two isolates. The data handed to this
-  // message will be disposed by calling free() once the message object is
-  // being destructed (after delivery or when the receiving port is closed).
-  PortMessage(intptr_t dest_id, intptr_t reply_id, void* data)
-      : next_(NULL),
-        dest_id_(dest_id),
-        reply_id_(reply_id),
-        data_(data) {}
-  ~PortMessage() {
-    free(data_);
-  }
+class Isolate;
+class Mutex;
 
-  intptr_t dest_id() const { return dest_id_; }
-  intptr_t reply_id() const { return reply_id_; }
-  void* data() const { return data_; }
-
-  void Handle();
-
- private:
-  PortMessage* next_;
-  intptr_t dest_id_;
-  intptr_t reply_id_;
-  void* data_;
-
-  friend class MessageQueue;
-
-  DISALLOW_COPY_AND_ASSIGN(PortMessage);
-};
-
-
-// There is a message queue per isolate. Access to the message queue should be
-// protected by the isolate monitor.
-class MessageQueue {
- public:
-  MessageQueue() : head_(NULL), tail_(NULL) {}
-  ~MessageQueue();
-
-  void Enqueue(PortMessage* msg);
-  PortMessage* Dequeue();
-
-  void Flush(intptr_t id);
-  void FlushAll();
-
- private:
-  PortMessage* head_;
-  PortMessage* tail_;
-
-  DISALLOW_COPY_AND_ASSIGN(MessageQueue);
-};
-
-
 class PortMap: public AllStatic {
  public:
   // Allocate a port in the current isolate and return its VM-global id.
-  static intptr_t CreatePort();
+  static Dart_Port CreatePort();
 
   // Close the port with id. All pending messages will be dropped.
-  static void ClosePort(intptr_t id);
+  static void ClosePort(Dart_Port id);
 
   // Close all the ports of the current isolate.
   static void ClosePorts();
 
-  static bool IsActivePort(intptr_t id);
+  static bool IsActivePort(Dart_Port id);
 
   // Enqueues the message in the port with id. Returns false if the port is not
   // active any longer.
-  static bool PostMessage(PortMessage* msg);
+  //
+  // Claims ownership of the memory pointed to by 'message' and will
+  // ensure that free(message) is called.
+  static bool PostMessage(Dart_Port dest_port,
+                          Dart_Port reply_port,
+                          Dart_Message message);
 
-  // Dequeue the next message pending for this isolate. Returns null if timeout
-  // was reached before a message was posted.
-  static PortMessage* ReceiveMessage(int64_t millis);
-
   static void InitOnce();
 
  private:
@@ -94,14 +43,14 @@
   // Free entries have id == 0 and isolate == NULL. Deleted entries have id == 0
   // and isolate == deleted_entry_.
   typedef struct {
-    intptr_t id;
+    Dart_Port port;
     Isolate* isolate;
   } Entry;
 
-  // Allocate a new unique port id.
-  static intptr_t AllocateId();
+  // Allocate a new unique port.
+  static Dart_Port AllocatePort();
 
-  static intptr_t FindId(intptr_t id);
+  static intptr_t FindPort(Dart_Port port);
   static void Rehash(intptr_t new_capacity);
 
   static void MaintainInvariants();
@@ -116,7 +65,7 @@
   static intptr_t used_;
   static intptr_t deleted_;
 
-  static intptr_t next_id_;
+  static Dart_Port next_port_;
 };
 
 }  // namespace dart