base/process_win.cc

   1 // Copyright (c) 2011 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/process.h"
   6 #include "base/logging.h"
   7 #include "base/memory/scoped_ptr.h"
   8 #include "base/process_util.h"
   9 #include "base/win/windows_version.h"
  10
  11 namespace base {
  12
  13 void Process::Close() {
  14   if (!process_)
  15     return;
  16
  17   // Don't call CloseHandle on a pseudo-handle.
  18   if (process_ != ::GetCurrentProcess())
  19     ::CloseHandle(process_);
  20
  21   process_ = NULL;
  22 }
  23
  24 void Process::Terminate(int result_code) {
  25   if (!process_)
  26     return;
  27
  28   // Call NtTerminateProcess directly, without going through the import table,
  29   // which might have been hooked with a buggy replacement by third party
  30   // software. http://crbug.com/81449.
  31   HMODULE module = GetModuleHandle(L"ntdll.dll");
  32   typedef UINT (WINAPI *TerminateProcessPtr)(HANDLE handle, UINT code);
  33   TerminateProcessPtr terminate_process = reinterpret_cast<TerminateProcessPtr>(
  34       GetProcAddress(module, "NtTerminateProcess"));
  35   terminate_process(process_, result_code);
  36 }
  37
  38 bool Process::IsProcessBackgrounded() const {
  39   if (!process_)
  40     return false;  // Failure case.
  41   DWORD priority = GetPriority();
  42   if (priority == 0)
  43     return false;  // Failure case.
  44   return ((priority == BELOW_NORMAL_PRIORITY_CLASS) ||
  45           (priority == IDLE_PRIORITY_CLASS));
  46 }
  47
  48 bool Process::SetProcessBackgrounded(bool value) {
  49   if (!process_)
  50     return false;
  51   // Vista and above introduce a real background mode, which not only
  52   // sets the priority class on the threads but also on the IO generated
  53   // by it. Unfortunately it can only be set for the calling process.
  54   DWORD priority;
  55   if ((base::win::GetVersion() >= base::win::VERSION_VISTA) &&
  56       (process_ == ::GetCurrentProcess())) {
  57     priority = value ? PROCESS_MODE_BACKGROUND_BEGIN :
  58                        PROCESS_MODE_BACKGROUND_END;
  59   } else {
  60     priority = value ? BELOW_NORMAL_PRIORITY_CLASS : NORMAL_PRIORITY_CLASS;
  61   }
  62
  63   return (::SetPriorityClass(process_, priority) != 0);
  64 }
  65
  66 ProcessId Process::pid() const {
  67   if (process_ == 0)
  68     return 0;
  69
  70   return GetProcId(process_);
  71 }
  72
  73 bool Process::is_current() const {
  74   return process_ == GetCurrentProcess();
  75 }
  76
  77 // static
  78 Process Process::Current() {
  79   return Process(::GetCurrentProcess());
  80 }
  81
  82 // static
  83 bool Process::CanBackgroundProcesses() {
  84   return true;
  85 }
  86
  87 int Process::GetPriority() const {
  88   DCHECK(process_);
  89   return ::GetPriorityClass(process_);
  90 }
  91
  92 }  // namespace base