dbus/file_descriptor.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 <algorithm>
   6
   7 #include "base/bind.h"
   8 #include "base/files/file.h"
   9 #include "base/location.h"
  10 #include "base/logging.h"
  11 #include "base/threading/worker_pool.h"
  12 #include "dbus/file_descriptor.h"
  13
  14 using std::swap;
  15
  16 namespace dbus {
  17
  18 void CHROME_DBUS_EXPORT FileDescriptor::Deleter::operator()(
  19     FileDescriptor* fd) {
  20   base::WorkerPool::PostTask(
  21       FROM_HERE, base::Bind(&base::DeletePointer<FileDescriptor>, fd), false);
  22 }
  23
  24 FileDescriptor::FileDescriptor(RValue other)
  25     : value_(-1), owner_(false), valid_(false) {
  26   Swap(other.object);
  27 }
  28
  29 FileDescriptor::~FileDescriptor() {
  30   if (owner_)
  31     base::File auto_closer(value_);
  32 }
  33
  34 FileDescriptor& FileDescriptor::operator=(RValue other) {
  35   Swap(other.object);
  36   return *this;
  37 }
  38
  39 int FileDescriptor::value() const {
  40   CHECK(valid_);
  41   return value_;
  42 }
  43
  44 int FileDescriptor::TakeValue() {
  45   CHECK(valid_);  // NB: check first so owner_ is unchanged if this triggers
  46   owner_ = false;
  47   return value_;
  48 }
  49
  50 void FileDescriptor::CheckValidity() {
  51   base::File file(value_);
  52   if (!file.IsValid()) {
  53     valid_ = false;
  54     return;
  55   }
  56
  57   base::File::Info info;
  58   bool ok = file.GetInfo(&info);
  59   file.TakePlatformFile();  // Prevent |value_| from being closed by |file|.
  60   valid_ = (ok && !info.is_directory);
  61 }
  62
  63 void FileDescriptor::Swap(FileDescriptor* other) {
  64   swap(value_, other->value_);
  65   swap(owner_, other->owner_);
  66   swap(valid_, other->valid_);
  67 }
  68
  69 }  // namespace dbus