websocket_async.c File Reference

Reactor-driven, callback-shaped non-blocking WebSocket path (C1M mode). More...

#include <cwist/net/websocket/websocket_async.h>
#include <cwist/core/mem/alloc.h>
#include <cwist/net/http/writer_fast.h>
#include <cwist/sys/io/reactor.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <pthread.h>
#include <stdatomic.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

Include dependency graph for websocket_async.c:

Go to the source code of this file.

Macros
#define	_GNU_SOURCE
#define	WS_ASYNC_MAX_PAYLOAD_BYTES   ((uint64_t)(16u * 1024u * 1024u))
#define	WS_ASYNC_MAX_MESSAGE_BYTES   ((size_t)(64u * 1024u * 1024u))
#define	WS_ASYNC_PARK_DEADLINE_SEC   30u
#define	WS_ASYNC_READ_CHUNK   16384u
#define	WS_ASYNC_SWEEP_SLICE_MS   100u

Typedefs
typedef struct ws_async_sweep	ws_async_sweep_t

Functions
int	cwist_websocket_async_send (cwist_websocket_async *ws, cwist_ws_opcode_t opcode, const uint8_t *data, size_t len)
	Send one complete WebSocket message frame on an async connection.
void	cwist_websocket_async_close (cwist_websocket_async *ws)
	Initiate the WebSocket close handshake with an empty CLOSE frame.
void	cwist_websocket_async_close_code (cwist_websocket_async *ws, uint16_t code)
	Initiate the WebSocket close handshake with a CLOSE frame carrying a status code.
cwist_websocket_async *	cwist_websocket_async_attach_ex (int fd, cwist_reactor_t *reactor, cwist_ws_on_message_t on_message, cwist_ws_on_close_t on_close, void *user_data, const uint8_t *initial, size_t initial_len)
	Attach an upgraded, HTTP-connection-owned fd to the reactor as an async WebSocket connection.
bool	cwist_websocket_async_attach (int fd, cwist_reactor_t *reactor, cwist_ws_on_message_t on_message, void *user_data, const uint8_t *initial, size_t initial_len)
	Attach an upgraded fd to the reactor as an async WebSocket connection (no on_close callback variant).

Detailed Description

Reactor-driven, callback-shaped non-blocking WebSocket path (C1M mode).

Issue #181: on the C1M path the route handler runs on the reactor thread, so the blocking recv() loop of cwist_websocket_receive() would park the entire worker. This module instead registers the upgraded fd with the reactor, drains it with non-blocking recv() calls, parses frames incrementally from a grow-by-doubling stash buffer (same model as the HTTP async connection rbuf), and delivers each complete message through the route's on_message callback.

Frame validation mirrors cwist_websocket_receive() rule-for-rule so both paths enforce identical RFC 6455 semantics (issues #145-#164).

Definition in file websocket_async.c.

Macro Definition Documentation

_GNU_SOURCE

#define _GNU_SOURCE

Definition at line 2 of file websocket_async.c.

WS_ASYNC_MAX_MESSAGE_BYTES

#define WS_ASYNC_MAX_MESSAGE_BYTES   ((size_t)(64u * 1024u * 1024u))

Definition at line 38 of file websocket_async.c.

WS_ASYNC_MAX_PAYLOAD_BYTES

#define WS_ASYNC_MAX_PAYLOAD_BYTES   ((uint64_t)(16u * 1024u * 1024u))

Definition at line 37 of file websocket_async.c.

WS_ASYNC_PARK_DEADLINE_SEC

#define WS_ASYNC_PARK_DEADLINE_SEC   30u

Definition at line 42 of file websocket_async.c.

WS_ASYNC_READ_CHUNK

#define WS_ASYNC_READ_CHUNK   16384u

Definition at line 44 of file websocket_async.c.

WS_ASYNC_SWEEP_SLICE_MS

#define WS_ASYNC_SWEEP_SLICE_MS   100u

Definition at line 410 of file websocket_async.c.

Typedef Documentation

ws_async_sweep_t

typedef struct ws_async_sweep ws_async_sweep_t

Definition at line 54 of file websocket_async.c.

Function Documentation

cwist_websocket_async_attach()

bool cwist_websocket_async_attach	(	int	fd,
		cwist_reactor_t *	reactor,
		cwist_ws_on_message_t	on_message,
		void *	user_data,
		const uint8_t *	initial,
		size_t	initial_len
	)

Attach an upgraded fd to the reactor as an async WebSocket connection (no on_close callback variant).

Take ownership of a connected, upgraded fd and drive it reactively.

Thin boolean wrapper around cwist_websocket_async_attach_ex().

Parameters

fd	Upgraded socket fd (owned by the new connection on success).
reactor	Reactor to register the fd with.
on_message	Callback invoked per complete message. Must not be NULL.
user_data	Opaque pointer passed back to the callback.
initial	Bytes already read past the upgrade request; may be NULL.
initial_len	Number of bytes in initial.

Return values

true	The connection was attached and the read slot armed.
false	Invalid arguments or failure (fd is closed).

Definition at line 1211 of file websocket_async.c.

References cap, and cwist_websocket_async_attach_ex().

cwist_websocket_async_attach_ex()

cwist_websocket_async * cwist_websocket_async_attach_ex	(	int	fd,
		cwist_reactor_t *	reactor,
		cwist_ws_on_message_t	on_message,
		cwist_ws_on_close_t	on_close,
		void *	user_data,
		const uint8_t *	initial,
		size_t	initial_len
	)

Attach an upgraded, HTTP-connection-owned fd to the reactor as an async WebSocket connection.

Attach variant that reports the connection handle and teardown.

Sets the fd non-blocking, feeds any bytes already read past the upgrade request through the parser (delivery can happen inline here, including a close from the on_message callback), arms the one-shot read slot, and joins the reactor's idle sweep. On any failure the fd is closed and all state is freed; on_close does not fire because the attach itself failed.

Parameters

fd	Upgraded socket fd (owned by the new connection on success).
reactor	Reactor to register the fd with.
on_message	Callback invoked per complete message; takes ownership of the delivered frame. Must not be NULL.
on_close	Optional callback invoked exactly once during teardown.
user_data	Opaque pointer passed back to both callbacks.
initial	Bytes already read past the upgrade request; may be NULL.
initial_len	Number of bytes in initial.

Returns

The new async connection, or NULL on invalid arguments or failure (fd is closed in the latter case).

Definition at line 1116 of file websocket_async.c.

References cap, cwist_alloc(), cwist_fast_monotonic_sec(), cwist_free(), cwist_reactor_add(), and CWIST_WS_FRAME_CONTINUATION.

Referenced by cwist_graphql_ws_attach(), and cwist_websocket_async_attach().

cwist_websocket_async_close()

void cwist_websocket_async_close

(

cwist_websocket_async *

ws

)

Initiate the WebSocket close handshake with an empty CLOSE frame.

Initiate the close handshake without blocking.

Idempotent: calling again on a connection already closing is a no-op. The connection is torn down once the CLOSE frame has drained or, on queueing failure, via a deferred termination.

Parameters

ws	Async connection to close. Safe to call with NULL.

Definition at line 725 of file websocket_async.c.

References cap, and CWIST_WS_FRAME_CLOSE.

cwist_websocket_async_close_code()

void cwist_websocket_async_close_code	(	cwist_websocket_async *	ws,
		uint16_t	code
	)

Initiate the WebSocket close handshake with a CLOSE frame carrying a status code.

The 2-byte big-endian status code is echoed to the peer. Idempotent: calling again on a connection already closing is a no-op. The connection is torn down once the CLOSE frame has drained or, on queueing failure, via a deferred termination.

Parameters

ws	Async connection to close. Safe to call with NULL.
code	RFC 6455 close status code (big-endian on the wire).

Definition at line 754 of file websocket_async.c.

References cap, and CWIST_WS_FRAME_CLOSE.

cwist_websocket_async_send()

int cwist_websocket_async_send	(	cwist_websocket_async *	ws,
		cwist_ws_opcode_t	opcode,
		const uint8_t *	data,
		size_t	len
	)

Send one complete WebSocket message frame on an async connection.

Serialize and send one FIN-terminated frame without blocking.

May be called from the reactor thread (e.g. inside the on_message callback); partial writes are parked and resumed by a POLLOUT slot.

Parameters

ws	Async connection.
opcode	Frame opcode (text, binary, PING, ...).
data	Payload bytes; may be NULL when len is 0.
len	Payload length in bytes.

Return values

0	The frame was sent or parked.
-1	Invalid arguments, the connection is already closing/closed, or queueing failed (the connection is torn down).

Definition at line 710 of file websocket_async.c.