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
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
const std = @import("../index.zig");
const builtin = @import("builtin");
const assert = std.debug.assert;
const event = std.event;
const mem = std.mem;
const posix = std.os.posix;
const windows = std.os.windows;
const Loop = std.event.Loop;
pub const Server = struct {
handleRequestFn: async<*mem.Allocator> fn (*Server, *const std.net.Address, *const std.os.File) void,
loop: *Loop,
sockfd: ?i32,
accept_coro: ?promise,
listen_address: std.net.Address,
waiting_for_emfile_node: PromiseNode,
listen_resume_node: event.Loop.ResumeNode,
const PromiseNode = std.LinkedList(promise).Node;
pub fn init(loop: *Loop) Server {
// TODO can't initialize handler coroutine here because we need well defined copy elision
return Server{
.loop = loop,
.sockfd = null,
.accept_coro = null,
.handleRequestFn = undefined,
.waiting_for_emfile_node = undefined,
.listen_address = undefined,
.listen_resume_node = event.Loop.ResumeNode{
.id = event.Loop.ResumeNode.Id.Basic,
.handle = undefined,
.overlapped = event.Loop.ResumeNode.overlapped_init,
},
};
}
pub fn listen(
self: *Server,
address: *const std.net.Address,
handleRequestFn: async<*mem.Allocator> fn (*Server, *const std.net.Address, *const std.os.File) void,
) !void {
self.handleRequestFn = handleRequestFn;
const sockfd = try std.os.posixSocket(posix.AF_INET, posix.SOCK_STREAM | posix.SOCK_CLOEXEC | posix.SOCK_NONBLOCK, posix.PROTO_tcp);
errdefer std.os.close(sockfd);
self.sockfd = sockfd;
try std.os.posixBind(sockfd, &address.os_addr);
try std.os.posixListen(sockfd, posix.SOMAXCONN);
self.listen_address = std.net.Address.initPosix(try std.os.posixGetSockName(sockfd));
self.accept_coro = try async<self.loop.allocator> Server.handler(self);
errdefer cancel self.accept_coro.?;
self.listen_resume_node.handle = self.accept_coro.?;
try self.loop.linuxAddFd(sockfd, &self.listen_resume_node, posix.EPOLLIN | posix.EPOLLOUT | posix.EPOLLET);
errdefer self.loop.removeFd(sockfd);
}
/// Stop listening
pub fn close(self: *Server) void {
self.loop.linuxRemoveFd(self.sockfd.?);
std.os.close(self.sockfd.?);
}
pub fn deinit(self: *Server) void {
if (self.accept_coro) |accept_coro| cancel accept_coro;
if (self.sockfd) |sockfd| std.os.close(sockfd);
}
pub async fn handler(self: *Server) void {
while (true) {
var accepted_addr: std.net.Address = undefined;
if (std.os.posixAccept(self.sockfd.?, &accepted_addr.os_addr, posix.SOCK_NONBLOCK | posix.SOCK_CLOEXEC)) |accepted_fd| {
var socket = std.os.File.openHandle(accepted_fd);
_ = async<self.loop.allocator> self.handleRequestFn(self, accepted_addr, socket) catch |err| switch (err) {
error.OutOfMemory => {
socket.close();
continue;
},
};
} else |err| switch (err) {
error.WouldBlock => {
suspend; // we will get resumed by epoll_wait in the event loop
continue;
},
error.ProcessFdQuotaExceeded => {
errdefer std.os.emfile_promise_queue.remove(&self.waiting_for_emfile_node);
suspend {
self.waiting_for_emfile_node = PromiseNode.init(@handle());
std.os.emfile_promise_queue.append(&self.waiting_for_emfile_node);
}
continue;
},
error.ConnectionAborted, error.FileDescriptorClosed => continue,
error.PageFault => unreachable,
error.InvalidSyscall => unreachable,
error.FileDescriptorNotASocket => unreachable,
error.OperationNotSupported => unreachable,
error.SystemFdQuotaExceeded, error.SystemResources, error.ProtocolFailure, error.BlockedByFirewall, error.Unexpected => {
@panic("TODO handle this error");
},
}
}
}
};
pub async fn connect(loop: *Loop, _address: *const std.net.Address) !std.os.File {
var address = _address.*; // TODO https://github.com/ziglang/zig/issues/733
const sockfd = try std.os.posixSocket(posix.AF_INET, posix.SOCK_STREAM | posix.SOCK_CLOEXEC | posix.SOCK_NONBLOCK, posix.PROTO_tcp);
errdefer std.os.close(sockfd);
try std.os.posixConnectAsync(sockfd, &address.os_addr);
try await try async loop.linuxWaitFd(sockfd, posix.EPOLLIN | posix.EPOLLOUT | posix.EPOLLET);
try std.os.posixGetSockOptConnectError(sockfd);
return std.os.File.openHandle(sockfd);
}
test "listen on a port, send bytes, receive bytes" {
if (builtin.os != builtin.Os.linux) {
// TODO build abstractions for other operating systems
return error.SkipZigTest;
}
const MyServer = struct {
tcp_server: Server,
const Self = @This();
async<*mem.Allocator> fn handler(tcp_server: *Server, _addr: *const std.net.Address, _socket: *const std.os.File) void {
const self = @fieldParentPtr(Self, "tcp_server", tcp_server);
var socket = _socket.*; // TODO https://github.com/ziglang/zig/issues/733
defer socket.close();
// TODO guarantee elision of this allocation
const next_handler = async errorableHandler(self, _addr, socket) catch unreachable;
(await next_handler) catch |err| {
std.debug.panic("unable to handle connection: {}\n", err);
};
suspend {
cancel @handle();
}
}
async fn errorableHandler(self: *Self, _addr: *const std.net.Address, _socket: std.os.File) !void {
const addr = _addr.*; // TODO https://github.com/ziglang/zig/issues/733
var socket = _socket; // TODO https://github.com/ziglang/zig/issues/733
var adapter = std.io.FileOutStream.init(socket);
var stream = &adapter.stream;
try stream.print("hello from server\n");
}
};
const ip4addr = std.net.parseIp4("127.0.0.1") catch unreachable;
const addr = std.net.Address.initIp4(ip4addr, 0);
var loop: Loop = undefined;
try loop.initSingleThreaded(std.debug.global_allocator);
var server = MyServer{ .tcp_server = Server.init(&loop) };
defer server.tcp_server.deinit();
try server.tcp_server.listen(addr, MyServer.handler);
const p = try async<std.debug.global_allocator> doAsyncTest(&loop, server.tcp_server.listen_address, &server.tcp_server);
defer cancel p;
loop.run();
}
async fn doAsyncTest(loop: *Loop, address: *const std.net.Address, server: *Server) void {
errdefer @panic("test failure");
var socket_file = try await try async connect(loop, address);
defer socket_file.close();
var buf: [512]u8 = undefined;
const amt_read = try socket_file.read(buf[0..]);
const msg = buf[0..amt_read];
assert(mem.eql(u8, msg, "hello from server\n"));
server.close();
}
|
