Change #262287

Comments

async-thrdd: use thread queue for resolving

Use a thread queue and pool for asnyc threaded DNS resolves.
Add pytest test_21_* for verification.

Add `CURLMOPT_RESOLVE_THREADS_MAX` to allow applications to
resize the thread pool used.

Add `CURLMOPT_QUICK_EXIT` to allow applications to skip thread
joins when cleaning up a multi handle. Multi handles in
`curl_easy_perform()` inherit this from `CURLOPT_QUICK_EXIT`.

Add several debug environment variables for testing.

Closes #20936

Changed files

• docs/libcurl/curl_multi_setopt.md
• docs/libcurl/libcurl-env-dbg.md
• docs/libcurl/opts/CURLMOPT_QUICK_EXIT.md
• docs/libcurl/opts/CURLMOPT_RESOLVE_THREADS_MAX.md
• docs/libcurl/opts/Makefile.inc
• docs/libcurl/symbols-in-versions
• include/curl/multi.h
• lib/asyn-thrdd.c
• lib/asyn.h
• lib/cf-socket.c
• lib/cfilters.c
• lib/cfilters.h
• lib/easy.c
• lib/ftp.c
• lib/hostip.c
• lib/hostip.h
• lib/hostip4.c
• lib/hostip6.c
• lib/multi.c
• lib/multihandle.h
• lib/socks.c
• lib/thrdpool.c
• lib/thrdpool.h
• lib/thrdqueue.c
• lib/thrdqueue.h
• lib/url.c
• src/tool_operate.c
• tests/data/test2500
• tests/http/Makefile.am
• tests/http/test_21_resolve.py
• tests/http/testenv/curl.py