Provide an iOS message pump for IO implementation.

base/mac/scoped_cffiledescriptorref.h

+// Copyright 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 BASE_MAC_SCOPED_CFFILEDESCRIPTORREF_H_
+#define BASE_MAC_SCOPED_CFFILEDESCRIPTORREF_H_
+
+#include <CoreFoundation/CoreFoundation.h>
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+
+namespace base {
+namespace mac {
+
+// ScopedCFFileDescriptorRef is designed after ScopedCFTypeRef<>. On
+// destruction, it will invalidate the file descriptor.
+// ScopedCFFileDescriptorRef (unlike ScopedCFTypeRef<>) does not support RETAIN
+// semantics, copying, or assignment, as doing so would increase the chances
+// that a file descriptor is invalidated while still in use.
+class ScopedCFFileDescriptorRef {
+ public:
+  explicit ScopedCFFileDescriptorRef(CFFileDescriptorRef fdref = NULL)
+      : fdref_(fdref) {
+  }
+
+  ~ScopedCFFileDescriptorRef() {
+    if (fdref_) {
+      CFFileDescriptorInvalidate(fdref_);
+      CFRelease(fdref_);
+    }
+  }
+
+  void reset(CFFileDescriptorRef fdref = NULL) {
+    if (fdref_ == fdref)
+      return;
+    if (fdref_) {
+      CFFileDescriptorInvalidate(fdref_);
+      CFRelease(fdref_);
+    }
+    fdref_ = fdref;
+  }
+
+  bool operator==(CFFileDescriptorRef that) const {
+    return fdref_ == that;
+  }
+
+  bool operator!=(CFFileDescriptorRef that) const {
+    return fdref_ != that;
+  }
+
+  operator CFFileDescriptorRef() const {
+    return fdref_;
+  }
+
+  CFFileDescriptorRef get() const {
+    return fdref_;
+  }
+
+  CFFileDescriptorRef release() WARN_UNUSED_RESULT {
+    CFFileDescriptorRef temp = fdref_;
+    fdref_ = NULL;
+    return temp;
+  }
+
+ private:
+  CFFileDescriptorRef fdref_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedCFFileDescriptorRef);
+};
+
+}  // namespace mac
+}  // namespace base
+
+#endif  // BASE_MAC_SCOPED_CFFILEDESCRIPTORREF_H_