base/win/scoped_process_information.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/win/scoped_process_information.h"
   6
   7 #include "base/logging.h"
   8 #include "base/win/scoped_handle.h"
   9
  10 namespace base {
  11 namespace win {
  12
  13 namespace {
  14
  15 // Closes the provided handle if it is not NULL.
  16 void CheckAndCloseHandle(HANDLE handle) {
  17   if (!handle)
  18     return;
  19   if (::CloseHandle(handle))
  20     return;
  21   CHECK(false);
  22 }
  23
  24 // Duplicates source into target, returning true upon success. |target| is
  25 // guaranteed to be untouched in case of failure. Succeeds with no side-effects
  26 // if source is NULL.
  27 bool CheckAndDuplicateHandle(HANDLE source, HANDLE* target) {
  28   if (!source)
  29     return true;
  30
  31   HANDLE temp = NULL;
  32   if (!::DuplicateHandle(::GetCurrentProcess(), source,
  33                          ::GetCurrentProcess(), &temp, 0, FALSE,
  34                          DUPLICATE_SAME_ACCESS)) {
  35     DPLOG(ERROR) << "Failed to duplicate a handle.";
  36     return false;
  37   }
  38   *target = temp;
  39   return true;
  40 }
  41
  42 }  // namespace
  43
  44 ScopedProcessInformation::ScopedProcessInformation()
  45     : process_information_() {
  46 }
  47
  48 ScopedProcessInformation::~ScopedProcessInformation() {
  49   Close();
  50 }
  51
  52 PROCESS_INFORMATION* ScopedProcessInformation::Receive() {
  53   DCHECK(!IsValid()) << "process_information_ must be NULL";
  54   return &process_information_;
  55 }
  56
  57 bool ScopedProcessInformation::IsValid() const {
  58   return process_information_.hThread || process_information_.hProcess ||
  59     process_information_.dwProcessId || process_information_.dwThreadId;
  60 }
  61
  62
  63 void ScopedProcessInformation::Close() {
  64   CheckAndCloseHandle(process_information_.hThread);
  65   CheckAndCloseHandle(process_information_.hProcess);
  66   Reset();
  67 }
  68
  69 void ScopedProcessInformation::Swap(ScopedProcessInformation* other) {
  70   DCHECK(other);
  71   PROCESS_INFORMATION temp = other->process_information_;
  72   other->process_information_ = process_information_;
  73   process_information_ = temp;
  74 }
  75
  76 bool ScopedProcessInformation::DuplicateFrom(
  77     const ScopedProcessInformation& other) {
  78   DCHECK(!IsValid()) << "target ScopedProcessInformation must be NULL";
  79   DCHECK(other.IsValid()) << "source ScopedProcessInformation must be valid";
  80
  81   ScopedHandle duplicate_process;
  82   ScopedHandle duplicate_thread;
  83
  84   if (CheckAndDuplicateHandle(other.process_handle(),
  85                               duplicate_process.Receive()) &&
  86       CheckAndDuplicateHandle(other.thread_handle(),
  87                               duplicate_thread.Receive())) {
  88     process_information_.dwProcessId = other.process_id();
  89     process_information_.dwThreadId = other.thread_id();
  90     process_information_.hProcess = duplicate_process.Take();
  91     process_information_.hThread = duplicate_thread.Take();
  92     return true;
  93   }
  94
  95   return false;
  96 }
  97
  98 PROCESS_INFORMATION ScopedProcessInformation::Take() {
  99   PROCESS_INFORMATION process_information = process_information_;
 100   Reset();
 101   return process_information;
 102 }
 103
 104 HANDLE ScopedProcessInformation::TakeProcessHandle() {
 105   HANDLE process = process_information_.hProcess;
 106   process_information_.hProcess = NULL;
 107   process_information_.dwProcessId = 0;
 108   return process;
 109 }
 110
 111 HANDLE ScopedProcessInformation::TakeThreadHandle() {
 112   HANDLE thread = process_information_.hThread;
 113   process_information_.hThread = NULL;
 114   process_information_.dwThreadId = 0;
 115   return thread;
 116 }
 117
 118 void ScopedProcessInformation::Reset() {
 119   process_information_.hThread = NULL;
 120   process_information_.hProcess = NULL;
 121   process_information_.dwProcessId = 0;
 122   process_information_.dwThreadId = 0;
 123 }
 124
 125 }  // namespace win
 126 }  // namespace base