ScopedProcessInformation protects against process/thread handle leaks from CreateProcess calls.

base/win/scoped_handle.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 BASE_WIN_SCOPED_HANDLE_H_
 #define BASE_WIN_SCOPED_HANDLE_H_
 #pragma once
 
 #include <windows.h>
 
@@ skipping 10 matching lines @@
 //     and INVALID_HANDLE_VALUE (-1) for Win32 handles.
 //   - Receive() method allows to receive a handle value from a function that
 //     takes a raw handle pointer only.
 template <class Traits>
 class GenericScopedHandle {
  public:
   typedef typename Traits::Handle Handle;
 
   GenericScopedHandle() : handle_(Traits::NullHandle()) {}
 
   explicit GenericScopedHandle(Handle handle) : handle_(Traits::NullHandle()) {

[alexeypa (please no reviews), 2012/03/15 16:38:27]

const Handle& handle

[erikwright (departed), 2012/03/15 18:02:44]

Done.

     Set(handle);
   }
 
   ~GenericScopedHandle() {
     Close();
   }
 
   bool IsValid() const {
     return Traits::IsHandleValid(handle_);
   }
 
   void Set(Handle handle) {

[alexeypa (please no reviews), 2012/03/15 16:38:27]

const Handle& handle

[erikwright (departed), 2012/03/15 18:02:44]

Done.

-    if (handle_ != handle) {
+    if (!Traits::IsSame(handle_, handle)) {
       Close();
 
       if (Traits::IsHandleValid(handle)) {
         handle_ = handle;
       }
     }
   }
 
   Handle Get() const {

[alexeypa (please no reviews), 2012/03/15 16:38:27]

Now that Handle is not a simple value this should return "const Handle&".

[erikwright (departed), 2012/03/15 18:02:44]

Done.

     return handle_;
   }
 
   operator Handle() const {
     return handle_;
   }
 
   Handle* Receive() {
     DCHECK(!Traits::IsHandleValid(handle_)) << "Handle must be NULL";
     return &handle_;
@@ skipping 30 matching lines @@
   // Closes the handle.
   static bool CloseHandle(HANDLE handle) {
     return ::CloseHandle(handle) != FALSE;
   }
 
   // Returns true if the handle value is valid.
   static bool IsHandleValid(HANDLE handle) {
     return handle != NULL && handle != INVALID_HANDLE_VALUE;
   }
 
+  // Returns true if the handle values are the same.
+  static bool IsSame(HANDLE lhs, HANDLE rhs) {
+    return lhs == rhs;
+  }
+
   // Returns NULL handle value.
   static HANDLE NullHandle() {
     return NULL;
   }
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(HandleTraits);
 };
 
 typedef GenericScopedHandle<HandleTraits> ScopedHandle;
 
 }  // namespace win
 }  // namespace base
 
 #endif  // BASE_SCOPED_HANDLE_WIN_H_