Cancellable


Object Hierarchy:

Object hierarchy for Cancellable

Description:

public class Cancellable : Object

GCancellable is a thread-safe operation cancellation stack used throughout GIO to allow for cancellation of synchronous and asynchronous operations.

Example: Socket listener, async:

Note:

Use telnet localhost 1024 or telnet localhost 1025 to create connections

Note:

Send "shutdown" to close the server.

public class Server : Object {
private Cancellable cancellable;

private class Source : Object {
public uint16 port { private set; get; }

public Source (uint16 port) {
this.port = port;
}
}

private async void worker_func (SocketConnection connection, Source source) {
try {
DataInputStream istream = new DataInputStream (connection.input_stream);
DataOutputStream ostream = new DataOutputStream (connection.output_stream);

// Get the received message:
string message = yield istream.read_line_async (Priority.DEFAULT, this.cancellable);
message._strip ();
print ("Received: %s\n", message);

// Response:
ostream.put_string (message, this.cancellable);
ostream.put_byte ('\n', this.cancellable);

if (message == "shutdown") {
this.cancellable.cancel ();
}
} catch (Error e) {
print ("Error: %s\n", e.message);
}
}

public async void listen (Cancellable cancellable) {
this.cancellable = cancellable;

try {
// Listen on port 1024 and 1025.
// Source is used as source-identifier.
SocketListener listener = new SocketListener ();
listener.add_inet_port (1024, new Source (1024));
listener.add_inet_port (1025, new Source (1025));

// Wait for connections:
while (true) {
// Get the connection:
Object source_obj;
SocketConnection connection = yield listener.accept_async (this.cancellable, out source_obj);

// Identify the source:
Source source = source_obj as Source;
assert (source != null);

print ("Accepted! (Source: %d)\n", source.port);

// Register a worker:
worker_func.begin (connection, source);
}
} catch (Error e) {
print ("Error: %s\n", e.message);
}
}

public static int main (string[] args) {
MainLoop loop = new MainLoop ();

// Used to shutdown the program:
Cancellable cancellable = new Cancellable ();
cancellable.cancelled.connect (() => {
loop.quit ();
});

new Server ().listen.begin (cancellable);
loop.run ();
return 0;
}
}

valac --pkg gio-2.0 GLib.SocketListener.accept_async.vala


Namespace: GLib
Package: gio-2.0

Content:

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