Mojo: Armed Watchers

mojo/edk/system/dispatcher.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_EDK_SYSTEM_DISPATCHER_H_
 #define MOJO_EDK_SYSTEM_DISPATCHER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 #include <ostream>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "mojo/edk/embedder/platform_handle.h"
 #include "mojo/edk/embedder/platform_shared_buffer.h"
 #include "mojo/edk/system/handle_signals_state.h"
 #include "mojo/edk/system/ports/name.h"
 #include "mojo/edk/system/system_impl_export.h"
-#include "mojo/edk/system/watcher.h"
+#include "mojo/edk/system/watch.h"
 #include "mojo/public/c/system/buffer.h"
 #include "mojo/public/c/system/data_pipe.h"
 #include "mojo/public/c/system/message_pipe.h"
 #include "mojo/public/c/system/types.h"
 
 namespace mojo {
 namespace edk {
 
 class Awakable;
 class Dispatcher;
@@ skipping 16 matching lines @@
     MojoHandle local_handle;
   };
 
   enum class Type {
     UNKNOWN = 0,
     MESSAGE_PIPE,
     DATA_PIPE_PRODUCER,
     DATA_PIPE_CONSUMER,
     SHARED_BUFFER,
     WAIT_SET,
+    WATCHER,
 
     // "Private" types (not exposed via the public interface):
     PLATFORM_HANDLE = -1,
   };
 
   // All Dispatchers must minimally implement these methods.
 
   virtual Type GetType() const = 0;
   virtual MojoResult Close() = 0;
 
-  ///////////// Watch API ////////////////////
+  ///////////// Watcher API ////////////////////
 
-  virtual MojoResult Watch(MojoHandleSignals signals,
-                           const Watcher::WatchCallback& callback,
-                           uintptr_t context);
-
+  virtual MojoResult WatchDispatcher(scoped_refptr<Dispatcher> dispatcher,
+                                     MojoHandleSignals signals,
+                                     uintptr_t context);
   virtual MojoResult CancelWatch(uintptr_t context);
+  virtual MojoResult Arm(uint32_t* num_ready_contexts,
+                         uintptr_t* ready_contexts,
+                         MojoResult* ready_results,
+                         MojoHandleSignalsState* ready_signals_states);
 
   ///////////// Message pipe API /////////////
 
   virtual MojoResult WriteMessage(std::unique_ptr<MessageForTransit> message,
                                   MojoWriteMessageFlags flags);
 
   virtual MojoResult ReadMessage(std::unique_ptr<MessageForTransit>* message,
                                  uint32_t* num_bytes,
                                  MojoHandle* handles,
                                  uint32_t* num_handles,
@@ skipping 64 matching lines @@
                                          uintptr_t* contexts);
 
   ///////////// General-purpose API for all handle types /////////
 
   // Gets the current handle signals state. (The default implementation simply
   // returns a default-constructed |HandleSignalsState|, i.e., no signals
   // satisfied or satisfiable.) Note: The state is subject to change from other
   // threads.
   virtual HandleSignalsState GetHandleSignalsState() const;
 
+  // Adds a WatcherDispatcher reference to this dispatcher, to be notified of
+  // all subsequent changes to handle state including signal changes or closure.
+  // The reference is associated with a |context| for disambiguation of
+  // removals.
+  virtual MojoResult AddWatcherRef(
+      const scoped_refptr<WatcherDispatcher>& watcher,
+      uintptr_t context);
+
+  // Removes a WatcherDispatcher reference from this dispatcher.
+  virtual MojoResult RemoveWatcherRef(WatcherDispatcher* watcher,
+                                      uintptr_t context);
+
   // Adds an awakable to this dispatcher, which will be woken up when this
   // object changes state to satisfy |signals| with context |context|. It will
   // also be woken up when it becomes impossible for the object to ever satisfy
   // |signals| with a suitable error status.
   //
   // If |signals_state| is non-null, on *failure* |*signals_state| will be set
   // to the current handle signals state (on success, it is left untouched).
   //
   // Returns:
   //  - |MOJO_RESULT_OK| if the awakable was added;
@@ skipping 78 matching lines @@
 // So logging macros and |DCHECK_EQ()|, etc. work.
 MOJO_SYSTEM_IMPL_EXPORT inline std::ostream& operator<<(std::ostream& out,
                                                         Dispatcher::Type type) {
   return out << static_cast<int>(type);
 }
 
 }  // namespace edk
 }  // namespace mojo
 
 #endif  // MOJO_EDK_SYSTEM_DISPATCHER_H_