Mercurial > hg > nginx-quic
view auto/cc/ccc @ 8896:aa28c802409f
Resolver: make TCP write timer event cancelable.
Similar to 70e65bf8dfd7, the change is made to ensure that the ability to
cancel resolver tasks is fully controlled by the caller. As mentioned in the
referenced commit, it is safe to make this timer cancelable because resolve
tasks can have their own timeouts that are not cancelable.
The scenario where this may become a problem is a periodic background resolve
task (not tied to a specific request or a client connection), which receives a
response with short TTL, large enough to warrant fallback to a TCP query.
With each event loop wakeup, we either have a previously set write timer
instance or schedule a new one. The non-cancelable write timer can delay or
block graceful shutdown of a worker even if the ngx_resolver_ctx_t->cancelable
flag is set by the API user, and there are no other tasks or connections.
We use the resolver API in this way to maintain the list of upstream server
addresses specified with the 'resolve' parameter, and there could be third-party
modules implementing similar logic.
author | Aleksei Bavshin <a.bavshin@f5.com> |
---|---|
date | Wed, 01 Jun 2022 20:17:23 -0700 |
parents | d620f497c50f |
children |
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# Copyright (C) Igor Sysoev # Copyright (C) Nginx, Inc. # Compaq C V6.5-207 ngx_include_opt="-I" # warnings CFLAGS="$CFLAGS -msg_enable level6 -msg_fatal level6" CFLAGS="$CFLAGS -msg_disable unknownmacro" CFLAGS="$CFLAGS -msg_disable unusedincl" CFLAGS="$CFLAGS -msg_disable unnecincl" CFLAGS="$CFLAGS -msg_disable nestincl" CFLAGS="$CFLAGS -msg_disable strctpadding" CFLAGS="$CFLAGS -msg_disable ansialiascast" CFLAGS="$CFLAGS -msg_disable inlinestoclsmod" CFLAGS="$CFLAGS -msg_disable cxxkeyword" CFLAGS="$CFLAGS -msg_disable longlongsufx" CFLAGS="$CFLAGS -msg_disable valuepres" # STUB CFLAGS="$CFLAGS -msg_disable truncintcast" CFLAGS="$CFLAGS -msg_disable trunclongcast" CFLAGS="$CFLAGS -msg_disable truncintasn" CFLAGS="$CFLAGS -msg_disable trunclongint" CFLAGS="$CFLAGS -msg_disable intconcastsgn" CFLAGS="$CFLAGS -msg_disable intconstsign" CFLAGS="$CFLAGS -msg_disable switchlong" CFLAGS="$CFLAGS -msg_disable subscrbounds2" CFLAGS="$CFLAGS -msg_disable hexoctunsign" CFLAGS="$CFLAGS -msg_disable ignorecallval" CFLAGS="$CFLAGS -msg_disable nonstandcast" CFLAGS="$CFLAGS -msg_disable embedcomment" CFLAGS="$CFLAGS -msg_disable unreachcode" CFLAGS="$CFLAGS -msg_disable questcompare2" CFLAGS="$CFLAGS -msg_disable unusedtop" CFLAGS="$CFLAGS -msg_disable unrefdecl" CFLAGS="$CFLAGS -msg_disable bitnotint"