| // 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_ |
| |
| #include "base/win/windows_types.h" |
| |
| #include "base/gtest_prod_util.h" |
| #include "base/logging.h" |
| #include "base/macros.h" |
| |
| // TODO(rvargas): remove this with the rest of the verifier. |
| #if defined(COMPILER_MSVC) |
| #include <intrin.h> |
| #define BASE_WIN_GET_CALLER _ReturnAddress() |
| #elif defined(COMPILER_GCC) |
| #define BASE_WIN_GET_CALLER \ |
| __builtin_extract_return_addr(\ __builtin_return_address(0)) |
| #endif |
| |
| namespace base { |
| namespace win { |
| |
| // Generic wrapper for raw handles that takes care of closing handles |
| // automatically. The class interface follows the style of |
| // the ScopedFILE class with two additions: |
| // - IsValid() method can tolerate multiple invalid handle values such as NULL |
| // and INVALID_HANDLE_VALUE (-1) for Win32 handles. |
| // - Set() (and the constructors and assignment operators that call it) |
| // preserve the Windows LastError code. This ensures that GetLastError() can |
| // be called after stashing a handle in a GenericScopedHandle object. Doing |
| // this explicitly is necessary because of bug 528394 and VC++ 2015. |
| template <class Traits, class Verifier> |
| class GenericScopedHandle { |
| public: |
| typedef typename Traits::Handle Handle; |
| |
| GenericScopedHandle() : handle_(Traits::NullHandle()) {} |
| |
| explicit GenericScopedHandle(Handle handle) : handle_(Traits::NullHandle()) { |
| Set(handle); |
| } |
| |
| GenericScopedHandle(GenericScopedHandle&& other) |
| : handle_(Traits::NullHandle()) { |
| Set(other.Take()); |
| } |
| |
| ~GenericScopedHandle() { Close(); } |
| |
| bool IsValid() const { return Traits::IsHandleValid(handle_); } |
| |
| GenericScopedHandle& operator=(GenericScopedHandle&& other) { |
| DCHECK_NE(this, &other); |
| Set(other.Take()); |
| return *this; |
| } |
| |
| void Set(Handle handle) { |
| if (handle_ != handle) { |
| // Preserve old LastError to avoid bug 528394. |
| auto last_error = ::GetLastError(); |
| Close(); |
| |
| if (Traits::IsHandleValid(handle)) { |
| handle_ = handle; |
| } |
| ::SetLastError(last_error); |
| } |
| } |
| |
| Handle Get() const { return handle_; } |
| |
| // Transfers ownership away from this object. |
| Handle Take() { |
| Handle temp = handle_; |
| handle_ = Traits::NullHandle(); |
| return temp; |
| } |
| |
| // Explicitly closes the owned handle. |
| void Close() { |
| if (Traits::IsHandleValid(handle_)) { |
| Traits::CloseHandle(handle_); |
| handle_ = Traits::NullHandle(); |
| } |
| } |
| |
| private: |
| FRIEND_TEST_ALL_PREFIXES(ScopedHandleTest, ActiveVerifierWrongOwner); |
| FRIEND_TEST_ALL_PREFIXES(ScopedHandleTest, ActiveVerifierUntrackedHandle); |
| Handle handle_; |
| |
| DISALLOW_COPY_AND_ASSIGN(GenericScopedHandle); |
| }; |
| |
| #undef BASE_WIN_GET_CALLER |
| |
| // The traits class for Win32 handles that can be closed via CloseHandle() API. |
| class HandleTraits { |
| public: |
| typedef HANDLE Handle; |
| |
| // Closes the handle. |
| static bool CloseHandle(HANDLE handle); |
| |
| // Returns true if the handle value is valid. |
| static bool IsHandleValid(HANDLE handle) { |
| return handle != NULL && handle != INVALID_HANDLE_VALUE; |
| } |
| |
| // Returns NULL handle value. |
| static HANDLE NullHandle() { return NULL; } |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(HandleTraits); |
| }; |
| |
| // Do-nothing verifier. |
| class DummyVerifierTraits { |
| public: |
| typedef HANDLE Handle; |
| |
| static void StartTracking(HANDLE handle, |
| const void* owner, |
| const void* pc1, |
| const void* pc2) {} |
| static void StopTracking(HANDLE handle, |
| const void* owner, |
| const void* pc1, |
| const void* pc2) {} |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(DummyVerifierTraits); |
| }; |
| |
| // Performs actual run-time tracking. |
| class VerifierTraits { |
| public: |
| typedef HANDLE Handle; |
| |
| static void StartTracking(HANDLE handle, |
| const void* owner, |
| const void* pc1, |
| const void* pc2); |
| static void StopTracking(HANDLE handle, |
| const void* owner, |
| const void* pc1, |
| const void* pc2); |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(VerifierTraits); |
| }; |
| |
| typedef GenericScopedHandle<HandleTraits, VerifierTraits> ScopedHandle; |
| |
| // This function may be called by the embedder to disable the use of |
| // VerifierTraits at runtime. It has no effect if DummyVerifierTraits is used |
| // for ScopedHandle. |
| void DisableHandleVerifier(); |
| |
| // This should be called whenever the OS is closing a handle, if extended |
| // verification of improper handle closing is desired. If |handle| is being |
| // tracked by the handle verifier and ScopedHandle is not the one closing it, |
| // a CHECK is generated. |
| void OnHandleBeingClosed(HANDLE handle); |
| } // namespace win |
| } // namespace base |
| |
| #endif // BASE_WIN_SCOPED_HANDLE_H_ |