From: Marcin Siodelski <marcin@isc.org>
Date: Tue, 13 Oct 2015 19:59:12 +0000 (+0200)
Subject: [4075] Added comment in the unit test about the usleep time selection.
X-Git-Tag: trac3874_base~10^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a045551c70df031afe42d65abeb7d0c8dd26acea;p=thirdparty%2Fkea.git

[4075] Added comment in the unit test about the usleep time selection.
---

diff --git a/src/lib/dhcpsrv/tests/alloc_engine_expiration_unittest.cc b/src/lib/dhcpsrv/tests/alloc_engine_expiration_unittest.cc
index 1472b3c4ac..f955109350 100644
--- a/src/lib/dhcpsrv/tests/alloc_engine_expiration_unittest.cc
+++ b/src/lib/dhcpsrv/tests/alloc_engine_expiration_unittest.cc
@@ -511,6 +511,12 @@ public:
     /// the approximate time that the reclamation of all leases would take and
     /// test that the timeouts for the leases' reclamation work as expected.
     ///
+    /// The value of 40ms is relatively high, but it has been selected to
+    /// mitigate the problems with usleep on some virtual machines. On those
+    /// machines the wakeup from usleep may take significant amount of time,
+    /// i.e. usually around 10ms. Thus, the sleep time should be considerably
+    /// higher than this delay.
+    ///
     /// @param callout_handle Callout handle.
     /// @return Zero.
     static int leaseExpireWithDelayCallout(CalloutHandle& callout_handle) {