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