SH-3690 SH-4505 Cleanup pass through code.

Start using DNS cache in legacy LLCurl code.  Go to 15 seconds
particularly as we're using threaded resolver at this point.
Documentation cleanup.  Add libcurl status checking and logging
for curl_easy_setopt() operations that fail.  Shouldn't happen
and we'll just continue anyway but there's info in the logs to
track these down now.  Cleaned up logic around FASTTIMER enable
defines used to evaluate pipeline stalls in main thread.
Removed long-standing thread race around caps strings and
URL construction.  Not a significant risk but refactoring the
code to get rid of them removed one huge eyesore.  It can be
made even slicker if desired (see notes).

1 files changed, 7 insertions, 4 deletions

diff --git a/indra/llmessage/llcurl.cpp b/indra/llmessage/llcurl.cpp
index f2a3e059ef..5193799ade 100755
--- a/indra/llmessage/llcurl.cpp
+++ b/indra/llmessage/llcurl.cpp
@@ -6,7 +6,7 @@
  *
  * $LicenseInfo:firstyear=2006&license=viewerlgpl$
  * Second Life Viewer Source Code
- * Copyright (C) 2010, Linden Research, Inc.
+ * Copyright (C) 2010-2013, Linden Research, Inc.
  * 
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -293,9 +293,12 @@ LLCurl::Easy* LLCurl::Easy::getEasy()
 		return NULL;
 	}
 	
-	// set no DNS caching as default for all easy handles. This prevents them adopting a
-	// multi handles cache if they are added to one.
-	CURLcode result = curl_easy_setopt(easy->mCurlEasyHandle, CURLOPT_DNS_CACHE_TIMEOUT, 0);
+	// Enable a brief cache period for now.  This was zero for the longest time
+	// which caused some routers grief and generated unneeded traffic.  For the
+	// threded resolver, we're using system resolution libraries and non-zero values
+	// are preferred.  The c-ares resolver is another matter and it might not
+	// track server changes as well.
+	CURLcode result = curl_easy_setopt(easy->mCurlEasyHandle, CURLOPT_DNS_CACHE_TIMEOUT, 15);
 	check_curl_code(result);
 	result = curl_easy_setopt(easy->mCurlEasyHandle, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);
 	check_curl_code(result);