Improve resolver cache lock and thread synchronization
This change comprises:
1. replace pthread_mutex with std::mutex to realize RAII.
2. have a single condition variable to prevent race condition between
threads.
3. add 'predicate' to avoid spurious awakenings.
4. add a parameter in GetResolverInfo API which enabling test cases to
know if timeout happened among concurrent DNS queries. Also, dump it in
bugreport.
5. verify if test case GetAddrInfoV6_concurrent,
GetAddrInfoStressTest_Binder_100 and
GetAddrInfoStressTest_Binder_100000 pass because of timeout on
concurrent DNS queries.
Bug: 120794954
Test: runtests.sh pass
Test: run ResolverTest.GetAddrInfoV6_concurrent 100 times
Test: run ResolverTest.GetAddrInfoStressTest_Binder_100 100 times
Test: run ResolverTest.GetAddrInfoStressTest_Binder_100000 100 times
The test script:
----------------------------
for i in $(seq 1 100)
do
adb shell resolv_integration_test --gtest_filter=ResolverTest.GetAddrInfoV6_concurrent
adb shell resolv_integration_test --gtest_filter=ResolverTest.GetAddrInfoStressTest_Binder_100
adb shell resolv_integration_test --gtest_filter=ResolverTest.GetAddrInfoStressTest_Binder_100000
done
exit 0
Change-Id: I4bdc394ba7ded7a6b7239f2d35b559a4262cb7b9
11 files changed