michael@0: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #ifndef BASE_WIN_SCOPED_PROCESS_INFORMATION_H_
michael@0: #define BASE_WIN_SCOPED_PROCESS_INFORMATION_H_
michael@0: 
michael@0: #include <windows.h>
michael@0: 
michael@0: #include "base/basictypes.h"
michael@0: #include "base/base_export.h"
michael@0: #include "base/win/scoped_handle.h"
michael@0: 
michael@0: namespace base {
michael@0: namespace win {
michael@0: 
michael@0: // Manages the closing of process and thread handles from PROCESS_INFORMATION
michael@0: // structures. Allows clients to take ownership of either handle independently.
michael@0: class BASE_EXPORT ScopedProcessInformation {
michael@0:  public:
michael@0:   // Helper object to contain the effect of Receive() to the funtion that needs
michael@0:   // a pointer.
michael@0:   class Receiver {
michael@0:    public:
michael@0:     explicit Receiver(ScopedProcessInformation* owner)
michael@0:         : info_(),
michael@0:           owner_(owner) {}
michael@0:     ~Receiver() { owner_->Set(info_); }
michael@0: 
michael@0:     operator PROCESS_INFORMATION*() { return &info_; }
michael@0: 
michael@0:    private:
michael@0:     PROCESS_INFORMATION info_;
michael@0:     ScopedProcessInformation* owner_;
michael@0:   };
michael@0: 
michael@0:   ScopedProcessInformation();
michael@0:   ~ScopedProcessInformation();
michael@0: 
michael@0:   // Returns an object that may be passed to API calls such as CreateProcess.
michael@0:   // DCHECKs that the object is not currently holding any handles.
michael@0:   // HANDLEs stored in the returned PROCESS_INFORMATION will be owned by this
michael@0:   // instance.
michael@0:   // The intended use case is something like this:
michael@0:   //   if (::CreateProcess(..., startup_info, scoped_proces_info.Receive()))
michael@0:   Receiver Receive();
michael@0: 
michael@0:   // Returns true iff this instance is holding a thread and/or process handle.
michael@0:   bool IsValid() const;
michael@0: 
michael@0:   // Closes the held thread and process handles, if any.
michael@0:   void Close();
michael@0: 
michael@0:   // Populates this instance with the provided |process_info|.
michael@0:   void Set(const PROCESS_INFORMATION& process_info);
michael@0: 
michael@0:   // Populates this instance with duplicate handles and the thread/process IDs
michael@0:   // from |other|. Returns false in case of failure, in which case this instance
michael@0:   // will be completely unpopulated.
michael@0:   bool DuplicateFrom(const ScopedProcessInformation& other);
michael@0: 
michael@0:   // Transfers ownership of the held PROCESS_INFORMATION, if any, away from this
michael@0:   // instance.
michael@0:   PROCESS_INFORMATION Take();
michael@0: 
michael@0:   // Transfers ownership of the held process handle, if any, away from this
michael@0:   // instance. Note that the related process_id will also be cleared.
michael@0:   HANDLE TakeProcessHandle();
michael@0: 
michael@0:   // Transfers ownership of the held thread handle, if any, away from this
michael@0:   // instance. Note that the related thread_id will also be cleared.
michael@0:   HANDLE TakeThreadHandle();
michael@0: 
michael@0:   // Returns the held process handle, if any, while retaining ownership.
michael@0:   HANDLE process_handle() const {
michael@0:     return process_handle_.Get();
michael@0:   }
michael@0: 
michael@0:   // Returns the held thread handle, if any, while retaining ownership.
michael@0:   HANDLE thread_handle() const {
michael@0:     return thread_handle_.Get();
michael@0:   }
michael@0: 
michael@0:   // Returns the held process id, if any.
michael@0:   DWORD process_id() const {
michael@0:     return process_id_;
michael@0:   }
michael@0: 
michael@0:   // Returns the held thread id, if any.
michael@0:   DWORD thread_id() const {
michael@0:     return thread_id_;
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   ScopedHandle process_handle_;
michael@0:   ScopedHandle thread_handle_;
michael@0:   DWORD process_id_;
michael@0:   DWORD thread_id_;
michael@0: 
michael@0:   DISALLOW_COPY_AND_ASSIGN(ScopedProcessInformation);
michael@0: };
michael@0: 
michael@0: }  // namespace win
michael@0: }  // namespace base
michael@0: 
michael@0: #endif  // BASE_WIN_SCOPED_PROCESS_INFORMATION_H_