diff options
Diffstat (limited to 'third_party/abseil_cpp/absl/base/spinlock_test_common.cc')
-rw-r--r-- | third_party/abseil_cpp/absl/base/spinlock_test_common.cc | 271 |
1 files changed, 0 insertions, 271 deletions
diff --git a/third_party/abseil_cpp/absl/base/spinlock_test_common.cc b/third_party/abseil_cpp/absl/base/spinlock_test_common.cc deleted file mode 100644 index dee266e4f4c0..000000000000 --- a/third_party/abseil_cpp/absl/base/spinlock_test_common.cc +++ /dev/null @@ -1,271 +0,0 @@ -// Copyright 2017 The Abseil Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// https://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -// A bunch of threads repeatedly hash an array of ints protected by a -// spinlock. If the spinlock is working properly, all elements of the -// array should be equal at the end of the test. - -#include <cstdint> -#include <limits> -#include <random> -#include <thread> // NOLINT(build/c++11) -#include <type_traits> -#include <vector> - -#include "gtest/gtest.h" -#include "absl/base/attributes.h" -#include "absl/base/config.h" -#include "absl/base/internal/low_level_scheduling.h" -#include "absl/base/internal/scheduling_mode.h" -#include "absl/base/internal/spinlock.h" -#include "absl/base/internal/sysinfo.h" -#include "absl/base/macros.h" -#include "absl/synchronization/blocking_counter.h" -#include "absl/synchronization/notification.h" - -constexpr int32_t kNumThreads = 10; -constexpr int32_t kIters = 1000; - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace base_internal { - -// This is defined outside of anonymous namespace so that it can be -// a friend of SpinLock to access protected methods for testing. -struct SpinLockTest { - static uint32_t EncodeWaitCycles(int64_t wait_start_time, - int64_t wait_end_time) { - return SpinLock::EncodeWaitCycles(wait_start_time, wait_end_time); - } - static uint64_t DecodeWaitCycles(uint32_t lock_value) { - return SpinLock::DecodeWaitCycles(lock_value); - } -}; - -namespace { - -static constexpr int kArrayLength = 10; -static uint32_t values[kArrayLength]; - -ABSL_CONST_INIT static SpinLock static_cooperative_spinlock( - absl::kConstInit, base_internal::SCHEDULE_COOPERATIVE_AND_KERNEL); -ABSL_CONST_INIT static SpinLock static_noncooperative_spinlock( - absl::kConstInit, base_internal::SCHEDULE_KERNEL_ONLY); - -// Simple integer hash function based on the public domain lookup2 hash. -// http://burtleburtle.net/bob/c/lookup2.c -static uint32_t Hash32(uint32_t a, uint32_t c) { - uint32_t b = 0x9e3779b9UL; // The golden ratio; an arbitrary value. - a -= b; a -= c; a ^= (c >> 13); - b -= c; b -= a; b ^= (a << 8); - c -= a; c -= b; c ^= (b >> 13); - a -= b; a -= c; a ^= (c >> 12); - b -= c; b -= a; b ^= (a << 16); - c -= a; c -= b; c ^= (b >> 5); - a -= b; a -= c; a ^= (c >> 3); - b -= c; b -= a; b ^= (a << 10); - c -= a; c -= b; c ^= (b >> 15); - return c; -} - -static void TestFunction(int thread_salt, SpinLock* spinlock) { - for (int i = 0; i < kIters; i++) { - SpinLockHolder h(spinlock); - for (int j = 0; j < kArrayLength; j++) { - const int index = (j + thread_salt) % kArrayLength; - values[index] = Hash32(values[index], thread_salt); - std::this_thread::yield(); - } - } -} - -static void ThreadedTest(SpinLock* spinlock) { - std::vector<std::thread> threads; - for (int i = 0; i < kNumThreads; ++i) { - threads.push_back(std::thread(TestFunction, i, spinlock)); - } - for (auto& thread : threads) { - thread.join(); - } - - SpinLockHolder h(spinlock); - for (int i = 1; i < kArrayLength; i++) { - EXPECT_EQ(values[0], values[i]); - } -} - -#ifndef ABSL_HAVE_THREAD_SANITIZER -static_assert(std::is_trivially_destructible<SpinLock>(), ""); -#endif - -TEST(SpinLock, StackNonCooperativeDisablesScheduling) { - SpinLock spinlock(base_internal::SCHEDULE_KERNEL_ONLY); - spinlock.Lock(); - EXPECT_FALSE(base_internal::SchedulingGuard::ReschedulingIsAllowed()); - spinlock.Unlock(); -} - -TEST(SpinLock, StaticNonCooperativeDisablesScheduling) { - static_noncooperative_spinlock.Lock(); - EXPECT_FALSE(base_internal::SchedulingGuard::ReschedulingIsAllowed()); - static_noncooperative_spinlock.Unlock(); -} - -TEST(SpinLock, WaitCyclesEncoding) { - // These are implementation details not exported by SpinLock. - const int kProfileTimestampShift = 7; - const int kLockwordReservedShift = 3; - const uint32_t kSpinLockSleeper = 8; - - // We should be able to encode up to (1^kMaxCycleBits - 1) without clamping - // but the lower kProfileTimestampShift will be dropped. - const int kMaxCyclesShift = - 32 - kLockwordReservedShift + kProfileTimestampShift; - const uint64_t kMaxCycles = (int64_t{1} << kMaxCyclesShift) - 1; - - // These bits should be zero after encoding. - const uint32_t kLockwordReservedMask = (1 << kLockwordReservedShift) - 1; - - // These bits are dropped when wait cycles are encoded. - const uint64_t kProfileTimestampMask = (1 << kProfileTimestampShift) - 1; - - // Test a bunch of random values - std::default_random_engine generator; - // Shift to avoid overflow below. - std::uniform_int_distribution<uint64_t> time_distribution( - 0, std::numeric_limits<uint64_t>::max() >> 4); - std::uniform_int_distribution<uint64_t> cycle_distribution(0, kMaxCycles); - - for (int i = 0; i < 100; i++) { - int64_t start_time = time_distribution(generator); - int64_t cycles = cycle_distribution(generator); - int64_t end_time = start_time + cycles; - uint32_t lock_value = SpinLockTest::EncodeWaitCycles(start_time, end_time); - EXPECT_EQ(0, lock_value & kLockwordReservedMask); - uint64_t decoded = SpinLockTest::DecodeWaitCycles(lock_value); - EXPECT_EQ(0, decoded & kProfileTimestampMask); - EXPECT_EQ(cycles & ~kProfileTimestampMask, decoded); - } - - // Test corner cases - int64_t start_time = time_distribution(generator); - EXPECT_EQ(kSpinLockSleeper, - SpinLockTest::EncodeWaitCycles(start_time, start_time)); - EXPECT_EQ(0, SpinLockTest::DecodeWaitCycles(0)); - EXPECT_EQ(0, SpinLockTest::DecodeWaitCycles(kLockwordReservedMask)); - EXPECT_EQ(kMaxCycles & ~kProfileTimestampMask, - SpinLockTest::DecodeWaitCycles(~kLockwordReservedMask)); - - // Check that we cannot produce kSpinLockSleeper during encoding. - int64_t sleeper_cycles = - kSpinLockSleeper << (kProfileTimestampShift - kLockwordReservedShift); - uint32_t sleeper_value = - SpinLockTest::EncodeWaitCycles(start_time, start_time + sleeper_cycles); - EXPECT_NE(sleeper_value, kSpinLockSleeper); - - // Test clamping - uint32_t max_value = - SpinLockTest::EncodeWaitCycles(start_time, start_time + kMaxCycles); - uint64_t max_value_decoded = SpinLockTest::DecodeWaitCycles(max_value); - uint64_t expected_max_value_decoded = kMaxCycles & ~kProfileTimestampMask; - EXPECT_EQ(expected_max_value_decoded, max_value_decoded); - - const int64_t step = (1 << kProfileTimestampShift); - uint32_t after_max_value = - SpinLockTest::EncodeWaitCycles(start_time, start_time + kMaxCycles + step); - uint64_t after_max_value_decoded = - SpinLockTest::DecodeWaitCycles(after_max_value); - EXPECT_EQ(expected_max_value_decoded, after_max_value_decoded); - - uint32_t before_max_value = SpinLockTest::EncodeWaitCycles( - start_time, start_time + kMaxCycles - step); - uint64_t before_max_value_decoded = - SpinLockTest::DecodeWaitCycles(before_max_value); - EXPECT_GT(expected_max_value_decoded, before_max_value_decoded); -} - -TEST(SpinLockWithThreads, StackSpinLock) { - SpinLock spinlock; - ThreadedTest(&spinlock); -} - -TEST(SpinLockWithThreads, StackCooperativeSpinLock) { - SpinLock spinlock(base_internal::SCHEDULE_COOPERATIVE_AND_KERNEL); - ThreadedTest(&spinlock); -} - -TEST(SpinLockWithThreads, StackNonCooperativeSpinLock) { - SpinLock spinlock(base_internal::SCHEDULE_KERNEL_ONLY); - ThreadedTest(&spinlock); -} - -TEST(SpinLockWithThreads, StaticCooperativeSpinLock) { - ThreadedTest(&static_cooperative_spinlock); -} - -TEST(SpinLockWithThreads, StaticNonCooperativeSpinLock) { - ThreadedTest(&static_noncooperative_spinlock); -} - -TEST(SpinLockWithThreads, DoesNotDeadlock) { - struct Helper { - static void NotifyThenLock(Notification* locked, SpinLock* spinlock, - BlockingCounter* b) { - locked->WaitForNotification(); // Wait for LockThenWait() to hold "s". - b->DecrementCount(); - SpinLockHolder l(spinlock); - } - - static void LockThenWait(Notification* locked, SpinLock* spinlock, - BlockingCounter* b) { - SpinLockHolder l(spinlock); - locked->Notify(); - b->Wait(); - } - - static void DeadlockTest(SpinLock* spinlock, int num_spinners) { - Notification locked; - BlockingCounter counter(num_spinners); - std::vector<std::thread> threads; - - threads.push_back( - std::thread(Helper::LockThenWait, &locked, spinlock, &counter)); - for (int i = 0; i < num_spinners; ++i) { - threads.push_back( - std::thread(Helper::NotifyThenLock, &locked, spinlock, &counter)); - } - - for (auto& thread : threads) { - thread.join(); - } - } - }; - - SpinLock stack_cooperative_spinlock( - base_internal::SCHEDULE_COOPERATIVE_AND_KERNEL); - SpinLock stack_noncooperative_spinlock(base_internal::SCHEDULE_KERNEL_ONLY); - Helper::DeadlockTest(&stack_cooperative_spinlock, - base_internal::NumCPUs() * 2); - Helper::DeadlockTest(&stack_noncooperative_spinlock, - base_internal::NumCPUs() * 2); - Helper::DeadlockTest(&static_cooperative_spinlock, - base_internal::NumCPUs() * 2); - Helper::DeadlockTest(&static_noncooperative_spinlock, - base_internal::NumCPUs() * 2); -} - -} // namespace -} // namespace base_internal -ABSL_NAMESPACE_END -} // namespace absl |