Mercurial > hg > nginx-quic
view auto/cc/acc @ 8746:84c60a3cd12a stable-1.20
Changed ngx_chain_update_chains() to test tag first (ticket #2248).
Without this change, aio used with HTTP/2 can result in connection hang,
as observed with "aio threads; aio_write on;" and proxying (ticket #2248).
The problem is that HTTP/2 updates buffers outside of the output filters
(notably, marks them as sent), and then posts a write event to call
output filters. If a filter does not call the next one for some reason
(for example, because of an AIO operation in progress), this might
result in a state when the owner of a buffer already called
ngx_chain_update_chains() and can reuse the buffer, while the same buffer
is still sitting in the busy chain of some other filter.
In the particular case a buffer was sitting in output chain's ctx->busy,
and was reused by event pipe. Output chain's ctx->busy was permanently
blocked by it, and this resulted in connection hang.
Fix is to change ngx_chain_update_chains() to skip buffers from other
modules unconditionally, without trying to wait for these buffers to
become empty.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Sat, 30 Oct 2021 02:39:19 +0300 |
parents | 9eefb38f0005 |
children |
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# Copyright (C) Igor Sysoev # Copyright (C) Nginx, Inc. # aCC: HP ANSI C++ B3910B A.03.55.02 # C89 mode CFLAGS="$CFLAGS -Ae" CC_TEST_FLAGS="-Ae" PCRE_OPT="$PCRE_OPT -Ae" ZLIB_OPT="$ZLIB_OPT -Ae"