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
|
// 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_posix.h"
#include <time.h>
#include <algorithm>
#include <vector>
#include "platform/base/error.h"
#include "platform/impl/socket_handle_posix.h"
#include "platform/impl/timeval_posix.h"
#include "platform/impl/udp_socket_posix.h"
#include "util/osp_logging.h"
namespace openscreen {
SocketHandleWaiterPosix::SocketHandleWaiterPosix(
ClockNowFunctionPtr now_function)
: SocketHandleWaiter(now_function) {}
SocketHandleWaiterPosix::~SocketHandleWaiterPosix() = default;
ErrorOr<std::vector<SocketHandleWaiterPosix::ReadyHandle>>
SocketHandleWaiterPosix::AwaitSocketsReadable(
const std::vector<SocketHandleRef>& socket_handles,
const Clock::duration& timeout) {
int max_fd = -1;
fd_set read_handles;
fd_set write_handles;
FD_ZERO(&read_handles);
FD_ZERO(&write_handles);
for (const SocketHandle& handle : socket_handles) {
FD_SET(handle.fd, &read_handles);
FD_SET(handle.fd, &write_handles);
max_fd = std::max(max_fd, handle.fd);
}
if (max_fd < 0) {
return Error::Code::kIOFailure;
}
struct timeval tv = ToTimeval(timeout);
// This value is set to 'max_fd + 1' by convention. Also, select() is
// level-triggered so incomplete reads/writes by the caller are fine and will
// be picked up again on the next select() call. For more information, see:
// http://man7.org/linux/man-pages/man2/select.2.html
int max_fd_to_watch = max_fd + 1;
const int rv =
select(max_fd_to_watch, &read_handles, &write_handles, nullptr, &tv);
if (rv == -1) {
// This is the case when an error condition is hit within the select(...)
// command.
return Error::Code::kIOFailure;
} else if (rv == 0) {
// This occurs when no sockets have a pending read.
return Error::Code::kAgain;
}
std::vector<ReadyHandle> changed_handles;
for (const SocketHandleRef& handle : socket_handles) {
uint32_t flags = 0;
if (FD_ISSET(handle.get().fd, &read_handles)) {
flags |= Flags::kReadable;
}
if (FD_ISSET(handle.get().fd, &write_handles)) {
flags |= Flags::kWriteable;
}
if (flags) {
changed_handles.push_back({handle, flags});
}
}
return changed_handles;
}
void SocketHandleWaiterPosix::RunUntilStopped() {
const bool was_running = is_running_.exchange(true);
OSP_CHECK(!was_running);
constexpr Clock::duration kHandleReadyTimeout = std::chrono::milliseconds(50);
while (is_running_) {
ProcessHandles(kHandleReadyTimeout);
}
}
void SocketHandleWaiterPosix::RequestStopSoon() {
is_running_.store(false);
}
} // namespace openscreen
|
