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 "net/dns/notify_watcher_mac.h"
6
7 #include <notify.h>
8
9 #include "base/logging.h"
10 #include "base/posix/eintr_wrapper.h"
11
12 namespace net {
13
NotifyWatcherMac()14 NotifyWatcherMac::NotifyWatcherMac() : notify_fd_(-1), notify_token_(-1) {}
15
~NotifyWatcherMac()16 NotifyWatcherMac::~NotifyWatcherMac() {
17 Cancel();
18 }
19
Watch(const char * key,const CallbackType & callback)20 bool NotifyWatcherMac::Watch(const char* key, const CallbackType& callback) {
21 DCHECK(key);
22 DCHECK(!callback.is_null());
23 Cancel();
24 uint32_t status = notify_register_file_descriptor(
25 key, ¬ify_fd_, 0, ¬ify_token_);
26 if (status != NOTIFY_STATUS_OK)
27 return false;
28 DCHECK_GE(notify_fd_, 0);
29 if (!base::MessageLoopForIO::current()->WatchFileDescriptor(
30 notify_fd_,
31 true,
32 base::MessageLoopForIO::WATCH_READ,
33 &watcher_,
34 this)) {
35 Cancel();
36 return false;
37 }
38 callback_ = callback;
39 return true;
40 }
41
Cancel()42 void NotifyWatcherMac::Cancel() {
43 if (notify_fd_ >= 0) {
44 notify_cancel(notify_token_); // Also closes |notify_fd_|.
45 notify_fd_ = -1;
46 callback_.Reset();
47 watcher_.StopWatchingFileDescriptor();
48 }
49 }
50
OnFileCanReadWithoutBlocking(int fd)51 void NotifyWatcherMac::OnFileCanReadWithoutBlocking(int fd) {
52 int token;
53 int status = HANDLE_EINTR(read(notify_fd_, &token, sizeof(token)));
54 if (status != sizeof(token)) {
55 Cancel();
56 callback_.Run(false);
57 return;
58 }
59 // Ignoring |token| value to avoid possible endianness mismatch:
60 // http://openradar.appspot.com/8821081
61 callback_.Run(true);
62 }
63
64 } // namespace net
65