blob: 8feebe00ae677e5cbb50d703051e1cfa4d4c952c (
plain)
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
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
|
// Copyright 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "platform/impl/socket_handle_waiter.h"
#include <algorithm>
#include <atomic>
#include "absl/algorithm/container.h"
#include "util/logging.h"
namespace openscreen {
void SocketHandleWaiter::Subscribe(Subscriber* subscriber,
SocketHandleRef handle) {
std::lock_guard<std::mutex> lock(mutex_);
if (handle_mappings_.find(handle) == handle_mappings_.end()) {
handle_mappings_.emplace(handle, subscriber);
}
}
void SocketHandleWaiter::Unsubscribe(Subscriber* subscriber,
SocketHandleRef handle) {
std::lock_guard<std::mutex> lock(mutex_);
auto iterator = handle_mappings_.find(handle);
if (handle_mappings_.find(handle) != handle_mappings_.end()) {
handle_mappings_.erase(iterator);
}
}
void SocketHandleWaiter::UnsubscribeAll(Subscriber* subscriber) {
std::lock_guard<std::mutex> lock(mutex_);
for (auto it = handle_mappings_.begin(); it != handle_mappings_.end();) {
if (it->second == subscriber) {
it = handle_mappings_.erase(it);
} else {
it++;
}
}
}
void SocketHandleWaiter::OnHandleDeletion(Subscriber* subscriber,
SocketHandleRef handle,
bool disable_locking_for_testing) {
std::unique_lock<std::mutex> lock(mutex_);
auto it = handle_mappings_.find(handle);
if (it != handle_mappings_.end()) {
handle_mappings_.erase(it);
if (!disable_locking_for_testing) {
handles_being_deleted_.push_back(handle);
// This code will allow us to block completion of the socket destructor
// (and subsequent invalidation of pointers to this socket) until we no
// longer are waiting on a SELECT(...) call to it, since we only signal
// this condition variable's wait(...) to proceed outside of SELECT(...).
handle_deletion_block_.wait(lock, [this, handle]() {
return std::find(handles_being_deleted_.begin(),
handles_being_deleted_.end(),
handle) == handles_being_deleted_.end();
});
}
}
}
void SocketHandleWaiter::ProcessReadyHandles(
const std::vector<SocketHandleRef>& handles) {
std::lock_guard<std::mutex> lock(mutex_);
for (const SocketHandleRef& handle : handles) {
auto iterator = handle_mappings_.find(handle);
if (iterator == handle_mappings_.end()) {
// This is OK: SocketHandle was deleted in the meantime.
continue;
}
iterator->second->ProcessReadyHandle(handle);
}
}
Error SocketHandleWaiter::ProcessHandles(Clock::duration timeout) {
std::vector<SocketHandleRef> handles;
{
std::lock_guard<std::mutex> lock(mutex_);
handles_being_deleted_.clear();
handle_deletion_block_.notify_all();
handles.reserve(handle_mappings_.size());
for (const auto& pair : handle_mappings_) {
handles.push_back(pair.first);
}
}
ErrorOr<std::vector<SocketHandleRef>> changed_handles =
AwaitSocketsReadable(handles, timeout);
{
std::lock_guard<std::mutex> lock(mutex_);
handles_being_deleted_.clear();
handle_deletion_block_.notify_all();
}
if (changed_handles.is_error()) {
return changed_handles.error();
}
ProcessReadyHandles(changed_handles.value());
return Error::None();
}
} // namespace openscreen
|
