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// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Single threaded tests of DnsHostInfo functionality.
#include <time.h>
#include <string>
#include "base/platform_thread.h"
#include "chrome/browser/net/dns_host_info.h"
#include "testing/gtest/include/gtest/gtest.h"
using base::TimeDelta;
namespace {
class DnsHostInfoTest : public testing::Test {
};
typedef chrome_browser_net::DnsHostInfo DnsHostInfo;
TEST(DnsHostInfoTest, StateChangeTest) {
DnsHostInfo info_practice, info;
std::string hostname1("domain1.com"), hostname2("domain2.com");
// First load DLL, so that their load time won't interfere with tests.
// Some tests involve timing function performance, and DLL time can overwhelm
// test durations (which are considering network vs cache response times).
info_practice.SetHostname(hostname2);
info_practice.SetQueuedState(DnsHostInfo::UNIT_TEST_MOTIVATED);
info_practice.SetAssignedState();
info_practice.SetFoundState();
PlatformThread::Sleep(500); // Allow time for DLLs to fully load.
// Complete the construction of real test object.
info.SetHostname(hostname1);
EXPECT_TRUE(info.NeedsDnsUpdate(hostname1)) << "error in construction state";
info.SetQueuedState(DnsHostInfo::UNIT_TEST_MOTIVATED);
EXPECT_FALSE(info.NeedsDnsUpdate(hostname1))
<< "update needed after being queued";
info.SetAssignedState();
EXPECT_FALSE(info.NeedsDnsUpdate(hostname1));
info.SetFoundState();
EXPECT_FALSE(info.NeedsDnsUpdate(hostname1))
<< "default expiration time is TOOOOO short";
// Note that time from ASSIGNED to FOUND was VERY short (probably 0ms), so the
// object should conclude that no network activity was needed. As a result,
// the required time till expiration will be halved (guessing that we were
// half way through having the cache expire when we did the lookup.
EXPECT_LT(info.resolve_duration().InMilliseconds(),
DnsHostInfo::kMaxNonNetworkDnsLookupDuration.InMilliseconds())
<< "Non-net time is set too low";
info.set_cache_expiration(TimeDelta::FromMilliseconds(300));
EXPECT_FALSE(info.NeedsDnsUpdate(hostname1)) << "expiration time not honored";
PlatformThread::Sleep(80); // Not enough time to pass our 300ms mark.
EXPECT_FALSE(info.NeedsDnsUpdate(hostname1)) << "expiration time not honored";
// That was a nice life when the object was found.... but next time it won't
// be found. We'll sleep for a while, and then come back with not-found.
info.SetQueuedState(DnsHostInfo::UNIT_TEST_MOTIVATED);
info.SetAssignedState();
EXPECT_FALSE(info.NeedsDnsUpdate(hostname1));
// Greater than minimal expected network latency on DNS lookup.
PlatformThread::Sleep(25);
info.SetNoSuchNameState();
EXPECT_FALSE(info.NeedsDnsUpdate(hostname1))
<< "default expiration time is TOOOOO short";
// Note that now we'll actually utilize an expiration of 300ms,
// since there was detected network activity time during lookup.
// We're assuming the caching just started with our lookup.
PlatformThread::Sleep(80); // Not enough time to pass our 300ms mark.
EXPECT_FALSE(info.NeedsDnsUpdate(hostname1)) << "expiration time not honored";
// Still not past our 300ms mark (only about 4+2ms)
PlatformThread::Sleep(80);
EXPECT_FALSE(info.NeedsDnsUpdate(hostname1)) << "expiration time not honored";
PlatformThread::Sleep(150);
EXPECT_TRUE(info.NeedsDnsUpdate(hostname1)) << "expiration time not honored";
}
// When a system gets "congested" relative to DNS, it means it is doing too many
// DNS resolutions, and bogging down the system. When we detect such a
// situation, we divert the sequence of states a DnsHostInfo instance moves
// through. Rather than proceeding from QUEUED (waiting in a name queue for a
// worker thread that can resolve the name) to ASSIGNED (where a worker thread
// actively resolves the name), we enter the ASSIGNED state (without actually
// getting sent to a resolver thread) and reset our state to what it was before
// the corresponding name was put in the work_queue_. This test drives through
// the state transitions used in such congestion handling.
TEST(DnsHostInfoTest, CongestionResetStateTest) {
DnsHostInfo info;
std::string hostname1("domain1.com");
info.SetHostname(hostname1);
info.SetQueuedState(DnsHostInfo::UNIT_TEST_MOTIVATED);
info.SetAssignedState();
EXPECT_TRUE(info.is_assigned());
info.RemoveFromQueue(); // Do the reset.
EXPECT_FALSE(info.is_assigned());
// Since this was a new info instance, and it never got resolved, we land back
// in a PENDING state rather than FOUND or NO_SUCH_NAME.
EXPECT_FALSE(info.was_found());
EXPECT_FALSE(info.was_nonexistant());
// Make sure we're completely re-usable, by going throug a normal flow.
info.SetQueuedState(DnsHostInfo::UNIT_TEST_MOTIVATED);
info.SetAssignedState();
info.SetFoundState();
EXPECT_TRUE(info.was_found());
// Use the congestion flow, and check that we end up in the found state.
info.SetQueuedState(DnsHostInfo::UNIT_TEST_MOTIVATED);
info.SetAssignedState();
info.RemoveFromQueue(); // Do the reset.
EXPECT_FALSE(info.is_assigned());
EXPECT_TRUE(info.was_found()); // Back to what it was before being queued.
}
// TODO(jar): Add death test for illegal state changes, and also for setting
// hostname when already set.
} // namespace
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