conncache: fix several lock issues

If the lock is released before the dealings with the bundle is over, it may
have changed by another thread in the mean time.

Fixes #2132
Fixes #2151
Closes #2139

1 files changed, 7 insertions, 3 deletions

diff --git a/lib/urldata.h b/lib/urldata.h
index ed6bbb4f0..19cb6cafd 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -775,9 +775,10 @@ struct connectdata {
   void *closesocket_client;
 
   bool inuse; /* This is a marker for the connection cache logic. If this is
-                 TRUE this handle is being used by an easy handle and cannot
-                 be used by any other easy handle without careful
-                 consideration (== only for pipelining). */
+                 TRUE this handle is being used by one or more easy handles
+                 and can only used by any other easy handle without careful
+                 consideration (== only for pipelining/multiplexing) and it
+                 cannot be used by another multi handle! */
 
   /**** Fields set when inited and not modified again */
   long connection_id; /* Contains a unique number to make it easier to
@@ -1325,6 +1326,9 @@ struct UrlState {
   struct Curl_easy *stream_depends_on;
   bool stream_depends_e; /* set or don't set the Exclusive bit */
   int stream_weight;
+#ifdef CURLDEBUG
+  bool conncache_lock;
+#endif
 };