external_commit_helper.hpp
2.25 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
////////////////////////////////////////////////////////////////////////////
//
// Copyright 2015 Realm Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////
#include <future>
namespace realm {
class Realm;
namespace _impl {
class RealmCoordinator;
class ExternalCommitHelper {
public:
ExternalCommitHelper(RealmCoordinator& parent);
~ExternalCommitHelper();
void notify_others();
private:
// A RAII holder for a file descriptor which automatically closes the wrapped
// fd when it's deallocated
class FdHolder {
public:
FdHolder() = default;
~FdHolder() { close(); }
operator int() const { return m_fd; }
FdHolder& operator=(int newFd) {
close();
m_fd = newFd;
return *this;
}
private:
int m_fd = -1;
void close();
FdHolder& operator=(FdHolder const&) = delete;
FdHolder(FdHolder const&) = delete;
};
void listen();
RealmCoordinator& m_parent;
// The listener thread
std::future<void> m_thread;
// Pipe which is waited on for changes and written to when there is a new
// commit to notify others of. When using a named pipe m_notify_fd is
// read-write and m_notify_fd_write is unused; when using an anonymous pipe
// (on tvOS) m_notify_fd is read-only and m_notify_fd_write is write-only.
FdHolder m_notify_fd;
FdHolder m_notify_fd_write;
// File descriptor for the kqueue
FdHolder m_kq;
// The two ends of an anonymous pipe used to notify the kqueue() thread that
// it should be shut down.
FdHolder m_shutdown_read_fd;
FdHolder m_shutdown_write_fd;
};
} // namespace _impl
} // namespace realm