sync/TcpAcceptor Reference

Listening TCP acceptor wrapper for incoming connections.

Handle and result model
Methods
Accept semantics
Examples
Example: accept one connection and print the remote address
See also

Handle and result model

Default construction creates an invalid acceptor handle.
Successful creation helpers return a valid acceptor on success.
valid? reports only whether the wrapper holds one non-invalid listening handle.
accept returns one connection wrapper, one host-order IPv4 address, and one result string.
The empty result string means success.
A non-empty result string means cancellation or failure and leaves the returned connection invalid.
The returned address is a success result only when the result string is empty.
A valid TcpAcceptor owns one listening socket. Destroying it closes that socket.

valid? (-- valid) Reports whether the handle refers to one listening acceptor.

accept (-- connection address result) Waits for one incoming connection and returns one connection wrapper, the remote IPv4 address as one host-order Nat32, and one result string.

Preconditions

The handle is valid.

Accept semantics

accept is one blocking sync-level wait.
accept returns when one connection is accepted, cancellation is observed, or an error is produced.
"canceled" means cancellation was observed before a successful accept completed.
Any other non-empty result string is an error description.
A successful accept leaves the acceptor valid for later accepts until it is destroyed.
The returned address is one host-order IPv4 Nat32 value.

Examples

Accept one connection and print the remote address

"sync/sync" use
"String" use
"control" use

{} Int32 {} [
  server: [
    result: String;
    acceptor: 0x7F000001n32 6612n16 listenTcp !result;
    [result.size 0 =] "listenTcp failed" ensure
    connection: address: acceptor.accept !result;;
    [result.size 0 =] "accept failed" ensure
    address ipv4ToString print
    LF print
  ];

  client: [
    result: String;
    connection: 0x7F000001n32 6612n16 connectTcp !result;
    [result.size 0 =] "connectTcp failed" ensure
  ];

  serverContext: @server () spawn;
  clientContext: @client () spawn;
  @serverContext.wait
  @clientContext.wait
  0
] "main" exportFunction

Expected Output

127.0.0.1