multi: cleanup the socket hash when destroying itbagder/sockhash-destroy

Since each socket hash entry may themselves have a hash table in them,
the destroying of the socket hash needs to make sure all the subhashes
are also correctly destroyed to avoid leaking memory.

Fixes #8129
Closes #8131

1 files changed, 27 insertions, 6 deletions

diff --git a/lib/multi.c b/lib/multi.c
index c34780f73..2bda97223 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -243,6 +243,26 @@ static void trhash_dtor(void *nada)
   (void)nada;
 }
 
+/*
+ * The sockhash has its own separate subhash in each entry that need to be
+ * safely destroyed first.
+ */
+static void sockhash_destroy(struct Curl_hash *h)
+{
+  struct Curl_hash_iterator iter;
+  struct Curl_hash_element *he;
+
+  DEBUGASSERT(h);
+  Curl_hash_start_iterate(h, &iter);
+  he = Curl_hash_next_element(&iter);
+  while(he) {
+    struct Curl_sh_entry *sh = (struct Curl_sh_entry *)he->ptr;
+    Curl_hash_destroy(&sh->transfers);
+    he = Curl_hash_next_element(&iter);
+  }
+  Curl_hash_destroy(h);
+}
+
 
 /* make sure this socket is present in the hash for this handle */
 static struct Curl_sh_entry *sh_addentry(struct Curl_hash *sh,
@@ -405,7 +425,7 @@ struct Curl_multi *Curl_multi_handle(int hashsize, /* socket hash */
 
   error:
 
-  Curl_hash_destroy(&multi->sockhash);
+  sockhash_destroy(&multi->sockhash);
   Curl_hash_destroy(&multi->hostcache);
   Curl_conncache_destroy(&multi->conn_cache);
   Curl_llist_destroy(&multi->msglist, NULL);
@@ -554,7 +574,7 @@ CURLMcode curl_multi_add_handle(struct Curl_multi *multi,
 #if 0
 /* Debug-function, used like this:
  *
- * Curl_hash_print(multi->sockhash, debug_print_sock_hash);
+ * Curl_hash_print(&multi->sockhash, debug_print_sock_hash);
  *
  * Enable the hash print function first by editing hash.c
  */
@@ -562,8 +582,8 @@ static void debug_print_sock_hash(void *p)
 {
   struct Curl_sh_entry *sh = (struct Curl_sh_entry *)p;
 
-  fprintf(stderr, " [easy %p/magic %x/socket %d]",
-          (void *)sh->data, sh->data->magic, (int)sh->socket);
+  fprintf(stderr, " [readers %u][writers %u]",
+          sh->readers, sh->writers);
 }
 #endif
 
@@ -576,7 +596,8 @@ static CURLcode multi_done(struct Curl_easy *data,
   struct connectdata *conn = data->conn;
   unsigned int i;
 
-  DEBUGF(infof(data, "multi_done"));
+  DEBUGF(infof(data, "multi_done: status: %d prem: %d done: %d",
+               (int)status, (int)premature, data->state.done));
 
   if(data->state.done)
     /* Stop if multi_done() has already been called */
@@ -2694,7 +2715,7 @@ CURLMcode curl_multi_cleanup(struct Curl_multi *multi)
     /* Close all the connections in the connection cache */
     Curl_conncache_close_all_connections(&multi->conn_cache);
 
-    Curl_hash_destroy(&multi->sockhash);
+    sockhash_destroy(&multi->sockhash);
     Curl_conncache_destroy(&multi->conn_cache);
     Curl_llist_destroy(&multi->msglist, NULL);
     Curl_llist_destroy(&multi->pending, NULL);