h3_socket.h¶

Structs¶

	Name
struct	h3_wakeup

Types¶

	Name
typedef struct h3_wakeup	h3_wakeup

Functions¶

	Name
apr_status_t	h3_socket_open(apr_port_t port, apr_size_t buffer_size, apr_pool_t * pool, int * out_fd)
void	h3_socket_close(int fd)
apr_status_t	h3_wakeup_create(apr_pool_t * pool, h3_wakeup * w)
void	h3_wakeup_signal(h3_wakeup * w)
void	h3_wakeup_drain(h3_wakeup * w)

Types Documentation¶

typedef h3_wakeup¶

typedef struct h3_wakeup h3_wakeup;

A way to interrupt the event thread's poll from another thread.

Loopback UDP rather than a pipe: Windows can only poll sockets.

Functions Documentation¶

function h3_socket_open¶

apr_status_t h3_socket_open(
    apr_port_t port,
    apr_size_t buffer_size,
    apr_pool_t * pool,
    int * out_fd
)

Parameters:

port Port to bind; 0 lets the OS pick.
buffer_size Bytes requested for SO_RCVBUF and SO_SNDBUF; 0 keeps the OS default.
pool Pool used for the underlying apr_socket_t lifetime.
out_fd Out parameter: the resulting OS-level fd (suitable for SSL_set_fd on OpenSSL QUIC).

Return: APR_SUCCESS, APR_EAGAIN if the port is already bound, or another APR error code.

Open a non-blocking IPv6 dual-stack UDP socket and bind it to the given port. Sets SO_REUSEADDR; on non-Windows also tries SO_REUSEPORT so multiple children can share the port. Also asks for buffer_size on the send and receive buffers, which the OS may cap; a refused or capped buffer is logged, never fatal.

function h3_socket_close¶

void h3_socket_close(
    int fd
)

Parameters:

fd The OS-level fd to close.

Close a UDP socket previously returned by h3_socket_open. Safe to call with a negative fd (no-op).

function h3_wakeup_create¶

apr_status_t h3_wakeup_create(
    apr_pool_t * pool,
    h3_wakeup * w
)

Parameters:

pool Pool owning both sockets.
w Out: the initialized pair; reset to reader_fd -1 on failure.

Return: APR_SUCCESS or an APR error code.

Create a wakeup pair on loopback. Both sockets are non-blocking.

function h3_wakeup_signal¶

void h3_wakeup_signal(
    h3_wakeup * w
)

Parameters:

w The pair to signal; NULL or uncreated is ignored.

Wake the event thread. Safe from any thread; a blocked send is dropped.

function h3_wakeup_drain¶

void h3_wakeup_drain(
    h3_wakeup * w
)

Parameters:

w The pair to drain; NULL or uncreated is ignored.

Discard everything queued on the reader, after poll reports it readable.

Source code¶

/*
 * Copyright (c) 2026 The mod_http3 Project Authors. All rights reserved.
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef H3_SOCKET_H
#define H3_SOCKET_H

#include <httpd.h>

#include <apr_network_io.h>
#include <apr_portable.h>

apr_status_t h3_socket_open(apr_port_t port, apr_size_t buffer_size, apr_pool_t* pool, int* out_fd);

void h3_socket_close(int fd);

typedef struct h3_wakeup
{
    apr_socket_t* reader;
    apr_socket_t* writer;
    apr_os_sock_t reader_fd; 
} h3_wakeup;

apr_status_t h3_wakeup_create(apr_pool_t* pool, h3_wakeup* w);

void h3_wakeup_signal(h3_wakeup* w);

void h3_wakeup_drain(h3_wakeup* w);

#endif /* H3_SOCKET_H */