docs/libcurl: expand multi documentation

curl_multi_init - mention the caches held by the handle

curl_multi_cleanup - mention that the socket callback might be invoked
by this function

Closes #15109

diff --git a/docs/libcurl/curl_multi_cleanup.md b/docs/libcurl/curl_multi_cleanup.md
index fb56e6468f5a9c1363b459377d8c5e868bc148b9..21661ea8a1471b39571e0d8b65c29ca4b8cab88d 100644 (file)
--- a/docs/libcurl/curl_multi_cleanup.md
+++ b/docs/libcurl/curl_multi_cleanup.md
@@ -41,6 +41,10 @@ handle is no longer connected to the multi handle
 3 - curl_multi_cleanup(3) should be called when all easy handles are
 removed
 
+When this function is called, remaining entries in the connection pool held by
+the multi handle are shut down, which might trigger calls to the
+CURLMOPT_SOCKETFUNCTION(3) callback.
+
 Passing in a NULL pointer in *multi_handle* makes this function return
 CURLM_BAD_HANDLE immediately with no other action.
 

diff --git a/docs/libcurl/curl_multi_init.md b/docs/libcurl/curl_multi_init.md
index 7c3dac8431c76fbd486518c925e29e7414444ebc..28c3d69c6b5e47ed49907e736a9fb77bc22773ed 100644 (file)
--- a/docs/libcurl/curl_multi_init.md
+++ b/docs/libcurl/curl_multi_init.md
@@ -34,6 +34,10 @@ all the other multi-functions, sometimes referred to as a multi handle in some
 places in the documentation. This init call MUST have a corresponding call to
 curl_multi_cleanup(3) when the operation is complete.
 
+By default, several caches are stored in and held by the multi handle: DNS
+cache, connection pool, TLS session ID cache and the TLS CA cert cache. All
+transfers using the same multi handle share these caches.
+
 # %PROTOCOLS%
 
 # EXAMPLE