diff options
| -rw-r--r-- | CHANGES | 20 | ||||
| -rw-r--r-- | RELEASE-NOTES | 4 | ||||
| -rw-r--r-- | lib/multi.c | 8 |
3 files changed, 28 insertions, 4 deletions
@@ -6,6 +6,26 @@ Changelog +Daniel Stenberg (1 June 2010) +- Igor Novoseltsev reported a problem with the multi socket API and using + timeouts and timers. It boiled down to a problem with libcurl's use of + GetTickCount() interally to figure out the current time, while Igor's own + application code used another function call. + + It made his app call the socket API timeout function a bit _before_ libcurl + would consider the timeout to trigger, and that could easily lead to + timeouts or stalls in the app. It seems GetTickCount() in general often has + no better resolution than 16ms and switching to the alternative function + QueryPerformanceCounter has its share of problems: + http://www.virtualdub.org/blog/pivot/entry.php?id=106 + + We address this problem by simply having libcurl treat timers that already + has occured or will occur within 40ms subject for treatment. I'm confident + that there are other implementations and operating systems with similarly in + accurate timer functions so it makes sense to have applied generically and I + don't believe we sacrifice much by adding a 40ms inaccuracy on these + timeouts. + Kamil Dudka (27 May 2010) - added a new test for CRL support (test313) diff --git a/RELEASE-NOTES b/RELEASE-NOTES index 86260d14f..7639afe28 100644 --- a/RELEASE-NOTES +++ b/RELEASE-NOTES @@ -33,6 +33,7 @@ This release includes the following bugfixes: o OpenSSL handshake state-machine for multi interface o TFTP timeout option sent correctly o TFTP block id wrap + o curl_multi_socket_action() timeout handles inaccuracy in timers better This release includes the following known bugs: @@ -43,6 +44,7 @@ advice from friends like these: Rainer Canavan, Paul Howarth, Jerome Vouillon, Ruslan Gazizov, Yang Tse, Kamil Dudka, Alex Bligh, Ben Greear, Hoi-Ho Chan, Howard Chu, Dirk Manske, - Pavel Raiskup, John-Mark Bell, Eric Mertens, Tor Arntsen, Douglas Kilpatrick + Pavel Raiskup, John-Mark Bell, Eric Mertens, Tor Arntsen, Douglas Kilpatrick, + Igor Novoseltsev Thanks! (and sorry if I forgot to mention someone) diff --git a/lib/multi.c b/lib/multi.c index 44771a309..06ffbd7b1 100644 --- a/lib/multi.c +++ b/lib/multi.c @@ -1994,9 +1994,11 @@ static CURLMcode multi_socket(struct Curl_multi *multi, extracts a matching node if there is one */ now = Curl_tvnow(); - now.tv_usec += 1000; /* to compensate for the truncating of 999us to 0ms, - we always add time here to make the comparison - below better */ + now.tv_usec += 40000; /* compensate for bad precision timers */ + if(now.tv_usec > 1000000) { + now.tv_sec++; + now.tv_usec -= 1000000; + } multi->timetree = Curl_splaygetbest(now, multi->timetree, &t); if(t) { |