components/browser_watcher/exit_code_watcher_win.cc

   1 // Copyright (c) 2014 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 "components/browser_watcher/exit_code_watcher_win.h"
   6
   7 #include "base/logging.h"
   8 #include "base/process/kill.h"
   9 #include "base/strings/stringprintf.h"
  10 #include "base/win/registry.h"
  11
  12 namespace browser_watcher {
  13
  14 namespace {
  15
  16 base::string16 GetValueName(const base::Time creation_time,
  17                             base::ProcessId pid) {
  18   // Convert the PID and creation time to a string value unique to this
  19   // process instance.
  20   return base::StringPrintf(L"%d-%lld", pid, creation_time.ToInternalValue());
  21 }
  22
  23 }  // namespace
  24
  25 ExitCodeWatcher::ExitCodeWatcher(const base::char16* registry_path) :
  26     registry_path_(registry_path), exit_code_(STILL_ACTIVE) {
  27 }
  28
  29 ExitCodeWatcher::~ExitCodeWatcher() {
  30 }
  31
  32 bool ExitCodeWatcher::Initialize(base::Process process) {
  33   if (!process.IsValid()) {
  34     LOG(ERROR) << "Invalid parent handle, can't get parent process ID.";
  35     return false;
  36   }
  37
  38   DWORD process_pid = process.Pid();
  39   if (process_pid == 0) {
  40     LOG(ERROR) << "Invalid parent handle, can't get parent process ID.";
  41     return false;
  42   }
  43
  44   FILETIME creation_time = {};
  45   FILETIME dummy = {};
  46   if (!::GetProcessTimes(process.Handle(), &creation_time, &dummy, &dummy,
  47                          &dummy)) {
  48     PLOG(ERROR) << "Invalid parent handle, can't get parent process times.";
  49     return false;
  50   }
  51
  52   // Success, take ownership of the process.
  53   process_ = process.Pass();
  54   process_creation_time_ = base::Time::FromFileTime(creation_time);
  55
  56   // Start by writing the value STILL_ACTIVE to registry, to allow detection
  57   // of the case where the watcher itself is somehow terminated before it can
  58   // write the process' actual exit code.
  59   return WriteProcessExitCode(STILL_ACTIVE);
  60 }
  61
  62 void ExitCodeWatcher::WaitForExit() {
  63   if (!process_.WaitForExit(&exit_code_)) {
  64     LOG(ERROR) << "Failed to wait for process.";
  65     return;
  66   }
  67
  68   WriteProcessExitCode(exit_code_);
  69 }
  70
  71 bool ExitCodeWatcher::WriteProcessExitCode(int exit_code) {
  72   base::win::RegKey key(HKEY_CURRENT_USER,
  73                         registry_path_.c_str(),
  74                         KEY_WRITE);
  75   base::string16 value_name(
  76       GetValueName(process_creation_time_, process_.Pid()));
  77
  78   ULONG result = key.WriteValue(value_name.c_str(), exit_code);
  79   if (result != ERROR_SUCCESS) {
  80     LOG(ERROR) << "Unable to write to registry, error " << result;
  81     return false;
  82   }
  83
  84   return true;
  85 }
  86
  87 }  // namespace browser_watcher