From 80b3de8753225f169e4269503d63c273562345e7 Mon Sep 17 00:00:00 2001 From: Nick Mathewson Date: Fri, 3 Sep 2010 12:06:04 -0400 Subject: Tolerate a little skew in accounting intervals. This will make changes for DST still work, and avoid double-spending bytes when there are slight changes to configurations. Fixes bug 1511; the DST issue is a bugfix on 0.0.9pre5. --- src/or/hibernate.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) (limited to 'src/or') diff --git a/src/or/hibernate.c b/src/or/hibernate.c index d50d05ed5..994b7ea93 100644 --- a/src/or/hibernate.c +++ b/src/or/hibernate.c @@ -341,6 +341,15 @@ start_of_accounting_period_after(time_t now) return edge_of_accounting_period_containing(now, 1); } +/** Return the length of the accounting period containing the time + * now. */ +static long +length_of_accounting_period_containing(time_t now) +{ + return edge_of_accounting_period_containing(now, 1) - + edge_of_accounting_period_containing(now, 0); +} + /** Initialize the accounting subsystem. */ void configure_accounting(time_t now) @@ -356,14 +365,26 @@ configure_accounting(time_t now) log_info(LD_ACCT, "Starting new accounting interval."); reset_accounting(now); } else if (interval_start_time == - start_of_accounting_period_containing(interval_start_time)) { + start_of_accounting_period_containing(interval_start_time)) { log_info(LD_ACCT, "Continuing accounting interval."); /* We are in the interval we thought we were in. Do nothing.*/ interval_end_time = start_of_accounting_period_after(interval_start_time); } else { - log_warn(LD_ACCT, - "Mismatched accounting interval; starting a fresh one."); - reset_accounting(now); + time_t s_now = start_of_accounting_period_containing(interval_start_time); + long duration = length_of_accounting_period_containing(interval_start_time); + double delta = ((double)(s_now - interval_start_time)) / duration; + if (-0.50 <= delta && delta <= 0.50) { + /* The start of the period is now a little later than we remembered. + * That's fine; we might lose a little time, but that's ok. */ + log_info(LD_ACCT, "Accounting interval moved by %.02f%%; " + "that's fine.", delta*100); + interval_end_time = start_of_accounting_period_after(interval_start_time); + } else { + log_warn(LD_ACCT, + "Mismatched accounting interval: moved by %.02f%%. " + "Starting a fresh one.", delta*100); + reset_accounting(now); + } } accounting_set_wakeup_time(); } -- cgit v1.2.3