generic-library/curl
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

resolve: cache lookup for async resolvers

Browse Source 
While waiting for a host resolve, check if the host cache may have
gotten the name already (by someone else), for when the same name is
resolved by several simultanoues requests.

The resolver thread occasionally gets stuck in getaddrinfo() when the
DNS or anything else is crappy or slow, so when a host is found in the
DNS cache, leave the thread alone and let itself cleanup the mess.
This commit is contained in:
Michael Wallner
2014-08-20 23:31:53 +02:00
committed by Daniel Stenberg
parent 2434a4e88d
commit 09b5a99816
4 changed files with 139 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
lib/multi.c
View File

@@ -30,6 +30,7 @@
#include "connect.h"
#include "progress.h"
#include "easyif.h"
#include "share.h"
#include "multiif.h"
#include "sendf.h"
#include "timeval.h"
@@ -1084,9 +1085,32 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi,
/* awaiting an asynch name resolve to complete */
{
struct Curl_dns_entry *dns = NULL;
struct connectdata *conn = data->easy_conn;
int stale;
/* check if we have the name resolved by now */
data->result = Curl_resolver_is_resolved(data->easy_conn, &dns);
if(data->share)
Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
dns = Curl_fetch_addr(conn, conn->host.name, (int)conn->port, &stale);
if(dns) {
dns->inuse++; /* we use it! */
#ifdef CURLRES_ASYNCH
conn->async.dns = dns;
conn->async.done = TRUE;
#endif
data->result = CURLRESOLV_RESOLVED;
infof(data, "Hostname was found in DNS cache\n");
}
if(stale)
infof(data, "Hostname in DNS cache was stale, zapped\n");
if(data->share)
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
if(!dns)
data->result = Curl_resolver_is_resolved(data->easy_conn, &dns);
/* Update sockets here, because the socket(s) may have been
closed and the application thus needs to be told, even if it