blob: 592c2ffabffebda8200caf7cec4d6aa507264fe0 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
|
/*
* Copyright 2023 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#ifndef OSSL_QUIC_THREAD_ASSIST_H
# define OSSL_QUIC_THREAD_ASSIST_H
# include <openssl/ssl.h>
# include "internal/thread.h"
# include "internal/time.h"
# if defined(OPENSSL_NO_QUIC) || defined(OPENSSL_NO_THREAD_POOL)
# define OPENSSL_NO_QUIC_THREAD_ASSIST
# endif
# ifndef OPENSSL_NO_QUIC_THREAD_ASSIST
/*
* QUIC Thread Assisted Functionality
* ==================================
*
* Where OS threading support is available, QUIC can optionally support a thread
* assisted mode of operation. The purpose of this mode of operation is to
* ensure that assorted timeout events which QUIC expects to be handled in a
* timely manner can be handled without the application needing to ensure that
* SSL_tick() is called on time. This is not needed if the application always
* has a call blocking to SSL_read() or SSL_write() (or another I/O function) on
* a QUIC SSL object, but if the application goes for long periods of time
* without making any such call to a QUIC SSL object, libssl cannot ordinarily
* guarantee that QUIC timeout events will be serviced in a timely fashion.
* Thread assisted mode is therefore of use to applications which do not always
* have an ongoing call to an I/O function on a QUIC SSL object but also do not
* want to have to arrange periodic ticking.
*
* A consequence of this is that the intrusiveness of thread assisted mode upon
* the general architecture of our QUIC engine is actually fairly limited and
* amounts to an automatic ticking of the QUIC engine when timeouts expire,
* synchronised correctly with an application's own threads using locking.
*/
typedef struct quic_thread_assist_st {
QUIC_CHANNEL *ch;
CRYPTO_CONDVAR *cv;
CRYPTO_THREAD *t;
int teardown, joined;
OSSL_TIME (*now_cb)(void *arg);
void *now_cb_arg;
} QUIC_THREAD_ASSIST;
/*
* Initialise the thread assist object. The channel must have a valid mutex
* configured on it which will be retrieved automatically. It is assumed that
* the mutex is currently held when this function is called. This function does
* not affect the state of the mutex.
*/
int ossl_quic_thread_assist_init_start(QUIC_THREAD_ASSIST *qta,
QUIC_CHANNEL *ch,
OSSL_TIME (*now_cb)(void *arg),
void *now_cb_arg);
/*
* Request the thread assist helper to begin stopping the assist thread. This
* returns before the teardown is complete. Idempotent; multiple calls to this
* function are inconsequential.
*
* Precondition: channel mutex must be held (unchecked)
*/
int ossl_quic_thread_assist_stop_async(QUIC_THREAD_ASSIST *qta);
/*
* Wait until the thread assist helper is torn down. This automatically implies
* the effects of ossl_quic_thread_assist_stop_async(). Returns immediately
* if the teardown has already completed.
*
* Precondition: channel mutex must be held (unchecked)
*/
int ossl_quic_thread_assist_wait_stopped(QUIC_THREAD_ASSIST *qta);
/*
* Deallocates state associated with the thread assist helper.
* ossl_quic_thread_assist_wait_stopped() must have returned successfully before
* calling this. It does not matter whether the channel mutex is held or not.
*
* Precondition: ossl_quic_thread_assist_wait_stopped() has returned 1
* (asserted)
*/
int ossl_quic_thread_assist_cleanup(QUIC_THREAD_ASSIST *qta);
/*
* Must be called to notify the assist thread if the channel deadline changes.
*
* Precondition: channel mutex must be held (unchecked)
*/
int ossl_quic_thread_assist_notify_deadline_changed(QUIC_THREAD_ASSIST *qta);
# endif
#endif
|
