傳回借用的資料。 • 適用 Rust 一般借用規則：可以由一個執行緒以可變方式借用，或者由任意數量的執行緒以不可變 方式借用。 309 第 59 部分 通道 Rust 通道分為兩個部分：Sender 和 Receiver。這兩個部分透過通道相連，但你只能看到端 點。 use std::sync::mpsc; fn main() { let (tx, rx) = mpsc::channel(); {:?}", rx.recv()); } • mpsc 代表多重生產者、唯一消費者。Sender 和 SyncSender 會實作 Clone (用於製作多重生 產者)，但 Receiver 不會。 • send() 和 recv() 會傳回 Result。如果傳回的是 Err，表示對應的 Sender 或 Receiver 已 釋放，且通道已關閉。 59.1 無界限的通道 你可以使用 mpsc::channel() Send + Sync，一般型別通常就會是 Send + Sync。 Send + !Sync 以下型別可以轉移到其他執行緒，但不會防護執行緒安全。原因通常在於內部可變性： • mpsc::Sender • mpsc::Receiver • Cell • RefCell !Send + Sync 以下型別會防護執行緒安全，但無法轉移至其他執行緒： • MutexGuard：使用

transmit data over UDP multicast, simply send to the socket. Notice that it is not necessary for a sender to join the multicast group. using Sockets group = ip"228.5.6.7" socket = Sockets.UDPSocket() ket, group) println(String(recv(socket))) leave_multicast_group(socket, group) close(socket) Sender: using Sockets group = Sockets.IPv6("ff05::5:6:7") socket = Sockets.UDPSocket() send(socket,

transmit data over UDP multicast, simply send to the socket. Notice that it is not necessary for a sender to join the multicast group. using Sockets group = ip"228.5.6.7" socket = Sockets.UDPSocket() ket, group) println(String(recv(socket))) leave_multicast_group(socket, group) close(socket) Sender: using Sockets group = Sockets.IPv6("ff05::5:6:7") socket = Sockets.UDPSocket() send(socket,

transmit data over UDP multicast, simply send to the socket. Notice that it is not necessary for a sender to join the multicast group. using Sockets group = ip"228.5.6.7" socket = Sockets.UDPSocket()CHAPTER ket, group) println(String(recv(socket))) leave_multicast_group(socket, group) close(socket) Sender: using Sockets group = Sockets.IPv6("ff05::5:6:7") socket = Sockets.UDPSocket() send(socket,

transmit data over UDP multicast, simply send to the socket. Notice that it is not necessary for a sender to join the multicast group. using Sockets group = ip"228.5.6.7" socket = Sockets.UDPSocket()CHAPTER ket, group) println(String(recv(socket))) leave_multicast_group(socket, group) close(socket) Sender: using Sockets group = Sockets.IPv6("ff05::5:6:7") socket = Sockets.UDPSocket() send(socket,

transmit data over UDP multicast, simply send to the socket. Notice that it is not necessary for a sender to join the multicast group. using Sockets group = ip"228.5.6.7" socket = Sockets.UDPSocket()CHAPTER ket, group) println(String(recv(socket))) leave_multicast_group(socket, group) close(socket) Sender: using Sockets group = Sockets.IPv6("ff05::5:6:7") socket = Sockets.UDPSocket() send(socket,

transmit data over UDP multicast, simply send to the socket. Notice that it is not necessary for a sender to join the multicast group. using Sockets group = ip"228.5.6.7" socket = Sockets.UDPSocket()CHAPTER ket, group) println(String(recv(socket))) leave_multicast_group(socket, group) close(socket) Sender: using Sockets group = Sockets.IPv6("ff05::5:6:7") socket = Sockets.UDPSocket() send(socket,

transmit data over UDP multicast, simply send to the socket. Notice that it is not necessary for a sender to join the multicast group. using Sockets group = ip"228.5.6.7" socket = Sockets.UDPSocket()CHAPTER ket, group) println(String(recv(socket))) leave_multicast_group(socket, group) close(socket) Sender: using Sockets group = Sockets.IPv6("ff05::5:6:7") socket = Sockets.UDPSocket() send(socket,

transmit data over UDP multicast, simply send to the socket. Notice that it is not necessary for a sender to join the multicast group. using Sockets group = ip"228.5.6.7" socket = Sockets.UDPSocket()CHAPTER ket, group) println(String(recv(socket))) leave_multicast_group(socket, group) close(socket) Sender: using Sockets group = Sockets.IPv6("ff05::5:6:7") socket = Sockets.UDPSocket() send(socket,

transmit data over UDP multicast, simply send to the socket. Notice that it is not necessary for a sender to join the multicast group. using Sockets group = ip"228.5.6.7" socket = Sockets.UDPSocket()CHAPTER ket, group) println(String(recv(socket))) leave_multicast_group(socket, group) close(socket) Sender: using Sockets group = Sockets.IPv6("ff05::5:6:7") socket = Sockets.UDPSocket() send(socket,