[NaCl SDK] nacl_io: Add initial implementations of kill and signal

native_client_sdk/src/libraries/nacl_io/kernel_object.h

 // Copyright (c) 2012 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 LIBRARIES_NACL_IO_KERNEL_OBJECT_H_
 #define LIBRARIES_NACL_IO_KERNEL_OBJECT_H_
 
 #include <pthread.h>
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "nacl_io/error.h"
+#include "nacl_io/event_emitter.h"
 #include "nacl_io/kernel_handle.h"
 #include "nacl_io/mount.h"
 #include "nacl_io/mount_node.h"
 #include "nacl_io/path.h"
 
 #include "sdk_util/simple_lock.h"
 
 namespace nacl_io {
 
 // KernelObject provides basic functionality for threadsafe access to kernel
 // objects such as the CWD, mount points, file descriptors and file handles.
 // All Kernel locks are private to ensure the lock order.
 //
 // All calls are assumed to be a relative path.
-class KernelObject {
+class KernelObject : public EventEmitter {
  public:
   typedef std::vector<ScopedKernelHandle> HandleMap_t;
   typedef std::map<std::string, ScopedMount> MountMap_t;
 
   KernelObject();
   virtual ~KernelObject();
 
   // Attach the given Mount object at the specified path.
   Error AttachMountAtPath(const ScopedMount& mnt, const std::string& path);
 
@@ skipping 28 matching lines @@
   void FreeAndReassignFD(int fd, const ScopedKernelHandle& handle);
   void FreeFD(int fd);
 
   // Returns or sets CWD
   std::string GetCWD();
   Error SetCWD(const std::string& path);
 
   // Returns parts of the absolute path for the given relative path
   Path GetAbsParts(const std::string& path);
 
+  // From EventEmitter.  The KernelObject emitters events in order
+  // to inturrupt anything waiting in select()/poll() when kill()
+  // is called.  It has no readable or wriable state and also no
+  // meaningful type.
+  uint32_t GetEventStatus() { return 0; }
+  int GetType() {
+    // For lack of a better type, report socket to signify it can be in an
+    // used to signal.
+    return S_IFSOCK;
+  }
 private:
   std::string cwd_;
   std::vector<int> free_fds_;
   HandleMap_t handle_map_;
   MountMap_t mounts_;
 
   // Lock to protect free_fds_ and handle_map_.
   sdk_util::SimpleLock handle_lock_;
 
   // Lock to protect handle_map_.
   sdk_util::SimpleLock mount_lock_;
 
   // Lock to protect cwd_.
   sdk_util::SimpleLock cwd_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(KernelObject);
 };
 
+typedef sdk_util::ScopedRef<KernelObject> ScopedKernelObject;
+
+
 }  // namespace nacl_io
 
 #endif  // LIBRARIES_NACL_IO_KERNEL_OBJECT_H_