autorelease message pumps

base/scoped_nsautorelease_pool.h

+// Copyright (c) 2008 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_SCOPED_NSAUTORELEASE_POOL_H_
+#define BASE_SCOPED_NSAUTORELEASE_POOL_H_
+
+#include "base/basictypes.h"
+
+#if defined(OS_MACOSX)
+#if defined(__OBJC__)
+@class NSAutoreleasePool;
+#else  // __OBJC__
+class NSAutoreleasePool;
+#endif  // __OBJC__
+#endif  // OS_MACOSX
+
+namespace base {
+
+// On the Mac, ScopedNSAutoreleasePool allocates an NSAutoreleasePool when
+// instantiated and sends it a -drain message when destroyed.  This allows an
+// autorelease pool to be maintained in ordinary C++ code without bringing in
+// any direct Objective-C dependency.
+//
+// On other platforms, ScopedNSAutoreleasePool is an empty object with no
+// effects.  This allows it to be used directly in cross-platform code without
+// ugly #ifdefs.
+class ScopedNSAutoreleasePool {
+#if defined(OS_MACOSX)
+ public:
+  ScopedNSAutoreleasePool();
+  ~ScopedNSAutoreleasePool();
+
+ private:
+  NSAutoreleasePool* autorelease_pool_;
+#endif  // OS_MACOSX
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ScopedNSAutoreleasePool);
+};
+
+}  // namespace base
+
+#endif  // BASE_SCOPED_NSAUTORELEASE_POOL_H_