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// Copyright 2016 The Cobalt Authors. All Rights Reserved.
//
// 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
//
// http://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.
// Adapted from base's atomicops_unittest.
#include "starboard/atomic.h"
#include "starboard/memory.h"
#include "starboard/thread.h"
#include "starboard/time.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace starboard {
namespace nplb {
namespace {
// Sets up an empty test fixture, required for typed tests.
// BasicSbAtomicTest contains test cases all enabled atomic types should pass.
template <class SbAtomicType>
class BasicSbAtomicTest : public testing::Test {
public:
BasicSbAtomicTest() {}
virtual ~BasicSbAtomicTest() {}
};
// AdvancedSbAtomicTest provides test coverage for all atomic functions.
// Atomic8 is right now the only atomic type not required to pass
// AdvancedSbAtomicTest, as it does not support implementations for the full
// set of atomic functions like the other types do.
template <class SbAtomicType>
class AdvancedSbAtomicTest : public BasicSbAtomicTest<SbAtomicType> {
public:
AdvancedSbAtomicTest() {}
virtual ~AdvancedSbAtomicTest() {}
};
typedef testing::Types<
SbAtomic8,
SbAtomic32,
#if SB_HAS(64_BIT_ATOMICS)
SbAtomic64,
#endif
SbAtomicPtr>
BasicSbAtomicTestTypes;
typedef testing::Types<SbAtomic32,
#if SB_HAS(64_BIT_ATOMICS)
SbAtomic64,
#endif
SbAtomicPtr> AdvancedSbAtomicTestTypes;
TYPED_TEST_CASE(BasicSbAtomicTest, BasicSbAtomicTestTypes);
TYPED_TEST_CASE(AdvancedSbAtomicTest, AdvancedSbAtomicTestTypes);
// Return an SbAtomicType with the value 0xa5a5a5...
template <class SbAtomicType>
SbAtomicType TestFillValue() {
SbAtomicType val = 0;
SbMemorySet(&val, 0xa5, sizeof(SbAtomicType));
return val;
}
// Returns the number of bits in a type.
template <class T>
T Bits() {
return (sizeof(T) * 8);
}
// Returns a value with the high bit |bits| from the most significant bit set.
template <class SbAtomicType>
SbAtomicType GetHighBitAt(int bits) {
return (SbAtomicType(1) << (Bits<SbAtomicType>() - (bits + 1)));
}
// Produces a test value that has non-zero bits in both halves, for testing
// 64-bit implementation on 32-bit platforms.
template <class SbAtomicType>
SbAtomicType GetTestValue() {
return GetHighBitAt<SbAtomicType>(1) + 11;
}
TYPED_TEST(BasicSbAtomicTest, ReleaseCompareAndSwapSingleThread) {
TypeParam value = 0;
TypeParam prev = atomic::Release_CompareAndSwap(&value, 0, 1);
EXPECT_EQ(1, value);
EXPECT_EQ(0, prev);
const TypeParam kTestValue = GetTestValue<TypeParam>();
value = kTestValue;
prev = atomic::Release_CompareAndSwap(&value, 0, 5);
EXPECT_EQ(kTestValue, value);
EXPECT_EQ(kTestValue, prev);
value = kTestValue;
prev = atomic::Release_CompareAndSwap(&value, kTestValue, 5);
EXPECT_EQ(5, value);
EXPECT_EQ(kTestValue, prev);
}
TYPED_TEST(BasicSbAtomicTest, NoBarrierStoreSingleThread) {
const TypeParam kVal1 = TestFillValue<TypeParam>();
const TypeParam kVal2 = static_cast<TypeParam>(-1);
TypeParam value;
atomic::NoBarrier_Store(&value, kVal1);
EXPECT_EQ(kVal1, value);
atomic::NoBarrier_Store(&value, kVal2);
EXPECT_EQ(kVal2, value);
}
TYPED_TEST(BasicSbAtomicTest, NoBarrierLoadSingleThread) {
const TypeParam kVal1 = TestFillValue<TypeParam>();
const TypeParam kVal2 = static_cast<TypeParam>(-1);
TypeParam value;
value = kVal1;
EXPECT_EQ(kVal1, atomic::NoBarrier_Load(&value));
value = kVal2;
EXPECT_EQ(kVal2, atomic::NoBarrier_Load(&value));
}
TYPED_TEST(AdvancedSbAtomicTest, IncrementSingleThread) {
// use a guard value to make sure the NoBarrier_AtomicIncrement doesn't go
// outside the expected address bounds. This is in particular to
// test that some future change to the asm code doesn't cause the
// 32-bit NoBarrier_AtomicIncrement doesn't do the wrong thing on 64-bit
// machines.
struct {
TypeParam prev_word;
TypeParam count;
TypeParam next_word;
} s;
TypeParam prev_word_value, next_word_value;
SbMemorySet(&prev_word_value, 0xFF, sizeof(TypeParam));
SbMemorySet(&next_word_value, 0xEE, sizeof(TypeParam));
s.prev_word = prev_word_value;
s.count = 0;
s.next_word = next_word_value;
EXPECT_EQ(atomic::NoBarrier_Increment(&s.count, 1), 1);
EXPECT_EQ(s.count, 1);
EXPECT_EQ(s.prev_word, prev_word_value);
EXPECT_EQ(s.next_word, next_word_value);
EXPECT_EQ(atomic::NoBarrier_Increment(&s.count, 2), 3);
EXPECT_EQ(s.count, 3);
EXPECT_EQ(s.prev_word, prev_word_value);
EXPECT_EQ(s.next_word, next_word_value);
EXPECT_EQ(atomic::NoBarrier_Increment(&s.count, 3), 6);
EXPECT_EQ(s.count, 6);
EXPECT_EQ(s.prev_word, prev_word_value);
EXPECT_EQ(s.next_word, next_word_value);
EXPECT_EQ(atomic::NoBarrier_Increment(&s.count, -3), 3);
EXPECT_EQ(s.count, 3);
EXPECT_EQ(s.prev_word, prev_word_value);
EXPECT_EQ(s.next_word, next_word_value);
EXPECT_EQ(atomic::NoBarrier_Increment(&s.count, -2), 1);
EXPECT_EQ(s.count, 1);
EXPECT_EQ(s.prev_word, prev_word_value);
EXPECT_EQ(s.next_word, next_word_value);
EXPECT_EQ(atomic::NoBarrier_Increment(&s.count, -1), 0);
EXPECT_EQ(s.count, 0);
EXPECT_EQ(s.prev_word, prev_word_value);
EXPECT_EQ(s.next_word, next_word_value);
EXPECT_EQ(atomic::NoBarrier_Increment(&s.count, -1), -1);
EXPECT_EQ(s.count, -1);
EXPECT_EQ(s.prev_word, prev_word_value);
EXPECT_EQ(s.next_word, next_word_value);
EXPECT_EQ(atomic::NoBarrier_Increment(&s.count, -4), -5);
EXPECT_EQ(s.count, -5);
EXPECT_EQ(s.prev_word, prev_word_value);
EXPECT_EQ(s.next_word, next_word_value);
EXPECT_EQ(atomic::NoBarrier_Increment(&s.count, 5), 0);
EXPECT_EQ(s.count, 0);
EXPECT_EQ(s.prev_word, prev_word_value);
EXPECT_EQ(s.next_word, next_word_value);
}
TYPED_TEST(AdvancedSbAtomicTest, NoBarrierCompareAndSwapSingleThread) {
TypeParam value = 0;
TypeParam prev = atomic::NoBarrier_CompareAndSwap(&value, 0, 1);
EXPECT_EQ(1, value);
EXPECT_EQ(0, prev);
const TypeParam kTestValue = GetTestValue<TypeParam>();
value = kTestValue;
prev = atomic::NoBarrier_CompareAndSwap(&value, 0, 5);
EXPECT_EQ(kTestValue, value);
EXPECT_EQ(kTestValue, prev);
value = kTestValue;
prev = atomic::NoBarrier_CompareAndSwap(&value, kTestValue, 5);
EXPECT_EQ(5, value);
EXPECT_EQ(kTestValue, prev);
}
TYPED_TEST(AdvancedSbAtomicTest, ExchangeSingleThread) {
TypeParam value = 0;
TypeParam new_value = atomic::NoBarrier_Exchange(&value, 1);
EXPECT_EQ(1, value);
EXPECT_EQ(0, new_value);
const TypeParam kTestValue = GetTestValue<TypeParam>();
value = kTestValue;
new_value = atomic::NoBarrier_Exchange(&value, kTestValue);
EXPECT_EQ(kTestValue, value);
EXPECT_EQ(kTestValue, new_value);
value = kTestValue;
new_value = atomic::NoBarrier_Exchange(&value, 5);
EXPECT_EQ(5, value);
EXPECT_EQ(kTestValue, new_value);
}
TYPED_TEST(AdvancedSbAtomicTest, IncrementBoundsSingleThread) {
// Test at rollover boundary between int_max and int_min
TypeParam test_val = GetHighBitAt<TypeParam>(0);
TypeParam value = -1 ^ test_val;
TypeParam new_value = atomic::NoBarrier_Increment(&value, 1);
EXPECT_EQ(test_val, value);
EXPECT_EQ(value, new_value);
atomic::NoBarrier_Increment(&value, -1);
EXPECT_EQ(-1 ^ test_val, value);
// Test at 32-bit boundary for 64-bit atomic type.
test_val = SB_UINT64_C(1) << (Bits<TypeParam>() / 2);
value = test_val - 1;
new_value = atomic::NoBarrier_Increment(&value, 1);
EXPECT_EQ(test_val, value);
EXPECT_EQ(value, new_value);
atomic::NoBarrier_Increment(&value, -1);
EXPECT_EQ(test_val - 1, value);
}
TYPED_TEST(AdvancedSbAtomicTest, BarrierStoreSingleThread) {
const TypeParam kVal1 = TestFillValue<TypeParam>();
const TypeParam kVal2 = static_cast<TypeParam>(-1);
TypeParam value;
atomic::Acquire_Store(&value, kVal1);
EXPECT_EQ(kVal1, value);
atomic::Acquire_Store(&value, kVal2);
EXPECT_EQ(kVal2, value);
atomic::Release_Store(&value, kVal1);
EXPECT_EQ(kVal1, value);
atomic::Release_Store(&value, kVal2);
EXPECT_EQ(kVal2, value);
}
TYPED_TEST(AdvancedSbAtomicTest, BarrierLoadSingleThread) {
const TypeParam kVal1 = TestFillValue<TypeParam>();
const TypeParam kVal2 = static_cast<TypeParam>(-1);
TypeParam value;
value = kVal1;
EXPECT_EQ(kVal1, atomic::Acquire_Load(&value));
value = kVal2;
EXPECT_EQ(kVal2, atomic::Acquire_Load(&value));
value = kVal1;
EXPECT_EQ(kVal1, atomic::Release_Load(&value));
value = kVal2;
EXPECT_EQ(kVal2, atomic::Release_Load(&value));
}
// Uses |state| to control initialization of |out_data| to |data| from multiple
// threads. This function was adapted from base/lazy_instance, to ensure I got
// the barrier operations correct.
template <class SbAtomicType>
void SetData(SbAtomicType* state,
char* out_data,
const char* data,
int data_size) {
const SbAtomicType kUninitialized = 0;
const SbAtomicType kInitializing = 1;
const SbAtomicType kInitialized = 2;
// Try to grab the initialization. If we're the first, will go from
// kUninitialized to kInitializing, otherwise we've been beaten. The memory
// access has no memory ordering as kUninitialized and kInitializing have no
// associated data (memory barriers are all about ordering of memory accesses
// to *associated* data).
if (atomic::NoBarrier_CompareAndSwap(state, kUninitialized, kInitializing) ==
kUninitialized) {
// We've locked the state, now we will initialize the data.
SbMemoryCopy(out_data, data, data_size);
// Signal the initialization has completed.
atomic::Release_Store(state, kInitialized);
return;
}
// It's either in the process of initializing, or already initialized. Spin.
// The load has acquire memory ordering as a thread which sees state_ ==
// kInitialized needs to acquire visibility over the associated data
// (out_data). The paired Release_Store is above in the initialization
// clause.
while (atomic::Acquire_Load(state) == kInitializing) {
SbThreadYield();
}
}
// A struct to pass through all the thread parameters.
template <class SbAtomicType>
struct TestOnceContext {
const char* data;
char* out_data;
SbAtomicType* state;
int size;
};
// The entry point for all the threads spawned during TestOnce().
template <class SbAtomicType>
void* TestOnceEntryPoint(void* raw_context) {
// Force every thread to sleep immediately so the first thread doesn't always
// just win.
SbThreadSleep(kSbTimeMillisecond);
TestOnceContext<SbAtomicType>* context =
reinterpret_cast<TestOnceContext<SbAtomicType>*>(raw_context);
SetData(context->state, context->out_data, context->data, context->size);
return NULL;
}
// Tests a "once"-like functionality implemented with Atomics. This should
// effectively test multi-threaded CompareAndSwap, Release_Store and
// Acquire_Load.
TYPED_TEST(AdvancedSbAtomicTest, OnceMultipleThreads) {
const int kNumTrials = 25;
const int kNumThreads = 12;
// Ensure each thread has slightly different data by offsetting it a bit as
// the 256-value pattern repeats.
const int kDataPerThread = 65534;
const int kTotalData = kDataPerThread * kNumThreads;
for (int trial = 0; trial < kNumTrials; ++trial) {
// The control variable to use atomics to synchronize on.
TypeParam state = 0;
// The target buffer to store the data.
char* target_data = new char[kDataPerThread];
SbMemorySet(target_data, 0, kDataPerThread);
// Each thread has a different set of data that it will try to set.
char* data = new char[kTotalData];
for (int i = 0; i < kTotalData; ++i) {
data[i] = static_cast<char>(i & 0xFF);
}
// Start up kNumThreads to fight over initializing |target_data|.
TestOnceContext<TypeParam> contexts[kNumThreads] = {0};
SbThread threads[kNumThreads] = {0};
for (int i = 0; i < kNumThreads; ++i) {
contexts[i].data = data + i * kDataPerThread;
contexts[i].out_data = target_data;
contexts[i].state = &state;
contexts[i].size = kDataPerThread;
threads[i] = SbThreadCreate(
0, kSbThreadNoPriority, kSbThreadNoAffinity, true, "TestOnceThread",
TestOnceEntryPoint<TypeParam>, &(contexts[i]));
EXPECT_TRUE(SbThreadIsValid(threads[i]));
}
// Wait for all threads to complete, and clean up their resources.
for (int i = 0; i < kNumThreads; ++i) {
EXPECT_TRUE(SbThreadJoin(threads[i], NULL));
}
// Ensure that exactly one thread initialized the data.
bool match = false;
for (int i = 0; i < kNumThreads; ++i) {
if (SbMemoryCompare(target_data, data + i * kDataPerThread,
kDataPerThread) == 0) {
match = true;
break;
}
}
EXPECT_TRUE(match) << "trial " << trial;
delete[] data;
delete[] target_data;
}
}
const int kNumIncrements = 4000;
template <class SbAtomicType>
void* IncrementEntryPoint(void* raw_context) {
SbAtomicType* target = reinterpret_cast<SbAtomicType*>(raw_context);
for (int i = 0; i < kNumIncrements; ++i) {
atomic::NoBarrier_Increment(target, 1);
}
return NULL;
}
template <class SbAtomicType>
void* DecrementEntryPoint(void* raw_context) {
SbAtomicType* target = reinterpret_cast<SbAtomicType*>(raw_context);
for (int i = 0; i < kNumIncrements; ++i) {
atomic::NoBarrier_Increment(target, -1);
}
return NULL;
}
TYPED_TEST(AdvancedSbAtomicTest, IncrementDecrementMultipleThreads) {
const int kNumTrials = 15;
const int kNumThreads = 12;
SB_COMPILE_ASSERT(kNumThreads % 2 == 0, kNumThreads_is_even);
const TypeParam kTestValue = GetTestValue<TypeParam>();
for (int trial = 0; trial < kNumTrials; ++trial) {
// The control variable to increment and decrement.
TypeParam value = kTestValue;
// Start up kNumThreads to fight.
SbThread threads[kNumThreads] = {0};
// First half are incrementers.
for (int i = 0; i < kNumThreads / 2; ++i) {
threads[i] = SbThreadCreate(0, kSbThreadNoPriority, kSbThreadNoAffinity,
true, "TestIncrementThread",
IncrementEntryPoint<TypeParam>, &value);
EXPECT_TRUE(SbThreadIsValid(threads[i]));
}
// Second half are decrementers.
for (int i = kNumThreads / 2; i < kNumThreads; ++i) {
threads[i] = SbThreadCreate(0, kSbThreadNoPriority, kSbThreadNoAffinity,
true, "TestDecrementThread",
DecrementEntryPoint<TypeParam>, &value);
EXPECT_TRUE(SbThreadIsValid(threads[i]));
}
// Wait for all threads to complete, and clean up their resources.
for (int i = 0; i < kNumThreads; ++i) {
EXPECT_TRUE(SbThreadJoin(threads[i], NULL));
}
// |value| should be back to its original value. If the increment/decrement
// isn't atomic, then the value should drift as the load + increment + store
// operations collide in funny ways.
EXPECT_EQ(kTestValue, value) << "trial " << trial;
}
}
} // namespace
} // namespace nplb
} // namespace starboard