disconnect: separate connections and easy handles better

Do not assume/store assocation between a given easy handle and the
connection if it can be avoided.

Long-term, the 'conn->data' pointer should probably be removed as it is a
little too error-prone. Still used very widely though.

Backported patch details:
https://github.com/curl/curl/pull/3400/commits/fb445a1e18d12f577964c9347bc5bca74b37cd08

Change-Id: I18aa2cb7097b8598c90ddf8c8c68a9fecd86e295
Signed-off-by: Niraj Kumar Goit <niraj.g@samsung.com>

diff --git a/lib/conncache.c b/lib/conncache.c
index 6fbf3b1d270b02867ef749737bc9fde9882721e5..d93119bed7235904952c963215b6ebe97fd94eaf 100644 (file)
--- a/lib/conncache.c
+++ b/lib/conncache.c
@@ -302,9 +302,14 @@ CURLcode Curl_conncache_add_conn(struct conncache *connc,
   return result;
 }
 
   return result;
 }
 

-void Curl_conncache_remove_conn(struct connectdata *conn, bool lock)
+/*
+ * Removes the connectdata object from the connection cache *and* clears the
+ * ->data pointer association. Pass TRUE/FALSE in the 'lock' argument
+ * depending on if the parent function already holds the lock or not.
+ */
+void Curl_conncache_remove_conn(struct Curl_easy *data,
+                                struct connectdata *conn, bool lock)

 {
 {

-  struct Curl_easy *data = conn->data;

   struct connectbundle *bundle = conn->bundle;
   struct conncache *connc = data->state.conn_cache;
 
   struct connectbundle *bundle = conn->bundle;
   struct conncache *connc = data->state.conn_cache;
 


@@ -323,6 +328,7 @@ void Curl_conncache_remove_conn(struct connectdata *conn, bool lock)
       DEBUGF(infof(data, "The cache now contains %zu members\n",
                    connc->num_conn));
     }
       DEBUGF(infof(data, "The cache now contains %zu members\n",
                    connc->num_conn));
     }

+    conn->data = NULL; /* clear the association */

     if(lock) {
       CONN_UNLOCK(data);
     }
     if(lock) {
       CONN_UNLOCK(data);
     }

diff --git a/lib/conncache.h b/lib/conncache.h
index eedd7a800ef8a730028b3020f2bbb9db75684db8..81566dcd345b41834645baab687f8a125b0b5992 100644 (file)
--- a/lib/conncache.h
+++ b/lib/conncache.h
@@ -64,7 +64,8 @@ size_t Curl_conncache_bundle_size(struct connectdata *conn);
 bool Curl_conncache_return_conn(struct connectdata *conn);
 CURLcode Curl_conncache_add_conn(struct conncache *connc,
                                  struct connectdata *conn) WARN_UNUSED_RESULT;
 bool Curl_conncache_return_conn(struct connectdata *conn);
 CURLcode Curl_conncache_add_conn(struct conncache *connc,
                                  struct connectdata *conn) WARN_UNUSED_RESULT;

-void Curl_conncache_remove_conn(struct connectdata *conn,
+void Curl_conncache_remove_conn(struct Curl_easy *data,
+                                struct connectdata *conn,

                                 bool lock);
 bool Curl_conncache_foreach(struct Curl_easy *data,
                             struct conncache *connc,
                                 bool lock);
 bool Curl_conncache_foreach(struct Curl_easy *data,
                             struct conncache *connc,

diff --git a/lib/multi.c b/lib/multi.c
index 7a2c1c3507835f63856bb54b358b6be69016c5b7..bd61824fcb3199ea29ec7b36eed0bf368660f417 100644 (file)
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -757,10 +757,8 @@ CURLMcode curl_multi_remove_handle(struct Curl_multi *multi,
                                 vanish with this handle */
 
   /* Remove the association between the connection and the handle */
                                 vanish with this handle */
 
   /* Remove the association between the connection and the handle */

-  if(data->easy_conn) {
-    data->easy_conn->data = NULL;
+  if(data->easy_conn)

     data->easy_conn = NULL;
     data->easy_conn = NULL;

-  }

 
 #ifdef USE_LIBPSL
   /* Remove the PSL association. */
 
 #ifdef USE_LIBPSL
   /* Remove the PSL association. */

diff --git a/lib/url.c b/lib/url.c
index bf1eb63f817aea3a04d317ca43a5c8e02d85598d..f50a99b0ff5fc19e3a0175c5fe8bb4ee6ae2d91e 100644 (file)
--- a/lib/url.c
+++ b/lib/url.c
@@ -773,7 +773,6 @@ CURLcode Curl_disconnect(struct Curl_easy *data,
     return CURLE_OK;
   }
 
     return CURLE_OK;
   }
 

-  conn->data = data;

   if(conn->dns_entry != NULL) {
     Curl_resolv_unlock(data, conn->dns_entry);
     conn->dns_entry = NULL;
   if(conn->dns_entry != NULL) {
     Curl_resolv_unlock(data, conn->dns_entry);
     conn->dns_entry = NULL;


@@ -792,14 +791,13 @@ CURLcode Curl_disconnect(struct Curl_easy *data,
 
     /* unlink ourselves! */
   infof(data, "Closing connection %ld\n", conn->connection_id);
 
     /* unlink ourselves! */
   infof(data, "Closing connection %ld\n", conn->connection_id);

-  Curl_conncache_remove_conn(conn, TRUE);
+  Curl_conncache_remove_conn(data, conn, TRUE);

 
   free_fixed_hostname(&conn->host);
   free_fixed_hostname(&conn->conn_to_host);
   free_fixed_hostname(&conn->http_proxy.host);
   free_fixed_hostname(&conn->socks_proxy.host);
 
 
   free_fixed_hostname(&conn->host);
   free_fixed_hostname(&conn->conn_to_host);
   free_fixed_hostname(&conn->http_proxy.host);
   free_fixed_hostname(&conn->socks_proxy.host);
 

-  DEBUGASSERT(conn->data == data);

   /* this assumes that the pointer is still there after the connection was
      detected from the cache */
   Curl_ssl_close(conn, FIRSTSOCKET);
   /* this assumes that the pointer is still there after the connection was
      detected from the cache */
   Curl_ssl_close(conn, FIRSTSOCKET);


@@ -964,8 +962,6 @@ static bool extract_if_dead(struct connectdata *conn,
        handles in pipeline and the connection isn't already marked in
        use */
     bool dead;
        handles in pipeline and the connection isn't already marked in
        use */
     bool dead;

-
-    conn->data = data;

     if(conn->handler->connection_check) {
       /* The protocol has a special method for checking the state of the
          connection. Use it to check if the connection is dead. */
     if(conn->handler->connection_check) {
       /* The protocol has a special method for checking the state of the
          connection. Use it to check if the connection is dead. */


@@ -981,8 +977,7 @@ static bool extract_if_dead(struct connectdata *conn,
 
     if(dead) {
       infof(data, "Connection %ld seems to be dead!\n", conn->connection_id);
 
     if(dead) {
       infof(data, "Connection %ld seems to be dead!\n", conn->connection_id);

-      Curl_conncache_remove_conn(conn, FALSE);
-      conn->data = NULL; /* detach */
+      Curl_conncache_remove_conn(data, conn, FALSE);

       return TRUE;
     }
   }
       return TRUE;
     }
   }