Mercurial > hg > nginx-quic
annotate src/core/ngx_crc.h @ 6536:f7849bfb6d21
Improved EPOLLRDHUP handling.
When it's known that the kernel supports EPOLLRDHUP, there is no need in
additional recv() call to get EOF or error when the flag is absent in the
event generated by the kernel. A special runtime test is done at startup
to detect if EPOLLRDHUP is actually supported by the kernel because
epoll_ctl() silently ignores unknown flags.
With this knowledge it's now possible to drop the "ready" flag for partial
read. Previously, the "ready" flag was kept until the recv() returned EOF
or error. In particular, this change allows the lingering close heuristics
(which relies on the "ready" flag state) to actually work on Linux, and not
wait for more data in most cases.
The "available" flag is now used in the read event with the semantics similar
to the corresponding counter in kqueue.
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Fri, 13 May 2016 17:19:23 +0300 |
parents | d620f497c50f |
children |
rev | line source |
---|---|
441
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
208
diff
changeset
|
1 |
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
208
diff
changeset
|
2 /* |
444
42d11f017717
nginx-0.1.0-2004-09-29-20:00:49 import; remove years from copyright
Igor Sysoev <igor@sysoev.ru>
parents:
441
diff
changeset
|
3 * Copyright (C) Igor Sysoev |
4412 | 4 * Copyright (C) Nginx, Inc. |
441
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
208
diff
changeset
|
5 */ |
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
208
diff
changeset
|
6 |
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
208
diff
changeset
|
7 |
201
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
8 #ifndef _NGX_CRC_H_INCLUDED_ |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
9 #define _NGX_CRC_H_INCLUDED_ |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
10 |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
11 |
792 | 12 #include <ngx_config.h> |
13 #include <ngx_core.h> | |
14 | |
15 | |
201
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
16 /* 32-bit crc16 */ |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
17 |
776 | 18 static ngx_inline uint32_t |
789 | 19 ngx_crc(u_char *data, size_t len) |
201
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
20 { |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
21 uint32_t sum; |
208
0b67be7d4489
nginx-0.0.1-2003-12-08-23:48:12 import
Igor Sysoev <igor@sysoev.ru>
parents:
201
diff
changeset
|
22 |
201
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
23 for (sum = 0; len; len--) { |
441
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
208
diff
changeset
|
24 |
201
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
25 /* |
776 | 26 * gcc 2.95.2 x86 and icc 7.1.006 compile |
27 * that operator into the single "rol" opcode, | |
201
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
28 * msvc 6.0sp2 compiles it into four opcodes. |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
29 */ |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
30 sum = sum >> 1 | sum << 31; |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
31 |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
32 sum += *data++; |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
33 } |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
34 |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
35 return sum; |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
36 } |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
37 |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
38 |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
39 #endif /* _NGX_CRC_H_INCLUDED_ */ |