multi: introduce sh_getentry() for looking up sockets in the sockhash

Simplify the code by using a single entry that looks for a socket in the
socket hash. As indicated in #712, the code looked for CURL_SOCKET_BAD
at some point and that is ineffective/wrong and this makes it easier to
avoid that.

1 files changed, 20 insertions, 22 deletions

diff --git a/lib/multi.c b/lib/multi.c
index 068ac48a1..f7624dd26 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -172,13 +172,22 @@ struct Curl_sh_entry {
 #define SH_READ  1
 #define SH_WRITE 2
 
+/* look up a given socket in the socket hash, skip invalid sockets */
+static struct Curl_sh_entry *sh_getentry(struct curl_hash *sh,
+                                         curl_socket_t s)
+{
+  if(s != CURL_SOCKET_BAD)
+    /* only look for proper sockets */
+    return Curl_hash_pick(sh, (char *)&s, sizeof(curl_socket_t));
+  return NULL;
+}
+
 /* make sure this socket is present in the hash for this handle */
 static struct Curl_sh_entry *sh_addentry(struct curl_hash *sh,
                                          curl_socket_t s,
                                          struct SessionHandle *data)
 {
-  struct Curl_sh_entry *there =
-    Curl_hash_pick(sh, (char *)&s, sizeof(curl_socket_t));
+  struct Curl_sh_entry *there = sh_getentry(sh, s);
   struct Curl_sh_entry *check;
 
   if(there)
@@ -206,15 +215,9 @@ static struct Curl_sh_entry *sh_addentry(struct curl_hash *sh,
 /* delete the given socket + handle from the hash */
 static void sh_delentry(struct curl_hash *sh, curl_socket_t s)
 {
-  struct Curl_sh_entry *there =
-    Curl_hash_pick(sh, (char *)&s, sizeof(curl_socket_t));
-
-  if(there) {
-    /* this socket is in the hash */
-    /* We remove the hash entry. (This'll end up in a call to
-       sh_freeentry().) */
-    Curl_hash_delete(sh, (char *)&s, sizeof(curl_socket_t));
-  }
+  /* We remove the hash entry. This will end up in a call to
+     sh_freeentry(). */
+  Curl_hash_delete(sh, (char *)&s, sizeof(curl_socket_t));
 }
 
 /*
@@ -2019,7 +2022,7 @@ static void singlesocket(struct Curl_multi *multi,
     s = socks[i];
 
     /* get it from the hash */
-    entry = Curl_hash_pick(&multi->sockhash, (char *)&s, sizeof(s));
+    entry = sh_getentry(&multi->sockhash, s);
 
     if(curraction & GETSOCK_READSOCK(i))
       action |= CURL_POLL_IN;
@@ -2070,7 +2073,7 @@ static void singlesocket(struct Curl_multi *multi,
       /* this socket has been removed. Tell the app to remove it */
       remove_sock_from_hash = TRUE;
 
-      entry = Curl_hash_pick(&multi->sockhash, (char *)&s, sizeof(s));
+      entry = sh_getentry(&multi->sockhash, s);
       if(entry) {
         /* check if the socket to be removed serves a connection which has
            other easy-s in a pipeline. In this case the socket should not be
@@ -2151,8 +2154,7 @@ void Curl_multi_closed(struct connectdata *conn, curl_socket_t s)
   if(multi) {
     /* this is set if this connection is part of a handle that is added to
        a multi handle, and only then this is necessary */
-    struct Curl_sh_entry *entry =
-      Curl_hash_pick(&multi->sockhash, (char *)&s, sizeof(s));
+    struct Curl_sh_entry *entry = sh_getentry(&multi->sockhash, s);
 
     if(entry) {
       if(multi->socket_cb)
@@ -2253,8 +2255,7 @@ static CURLMcode multi_socket(struct Curl_multi *multi,
   }
   else if(s != CURL_SOCKET_TIMEOUT) {
 
-    struct Curl_sh_entry *entry =
-      Curl_hash_pick(&multi->sockhash, (char *)&s, sizeof(s));
+    struct Curl_sh_entry *entry = sh_getentry(&multi->sockhash, s);
 
     if(!entry)
       /* Unmatched socket, we can't act on it but we ignore this fact.  In
@@ -2741,9 +2742,7 @@ CURLMcode curl_multi_assign(CURLM *multi_handle,
   struct Curl_sh_entry *there = NULL;
   struct Curl_multi *multi = (struct Curl_multi *)multi_handle;
 
-  if(s != CURL_SOCKET_BAD)
-    there = Curl_hash_pick(&multi->sockhash, (char *)&s,
-                           sizeof(curl_socket_t));
+  there = sh_getentry(&multi->sockhash, s);
 
   if(!there)
     return CURLM_BAD_SOCKET;
@@ -2821,8 +2820,7 @@ void Curl_multi_dump(const struct Curl_multi *multi_handle)
               statename[data->mstate], data->numsocks);
       for(i=0; i < data->numsocks; i++) {
         curl_socket_t s = data->sockets[i];
-        struct Curl_sh_entry *entry =
-          Curl_hash_pick(&multi->sockhash, (char *)&s, sizeof(s));
+        struct Curl_sh_entry *entry = sh_getentry(&multi->sockhash, s);
 
         fprintf(stderr, "%d ", (int)s);
         if(!entry) {