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// Copyright (c) 2011 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.
#include "base/atomicops.h"
#include <stdint.h>
#include <string.h>
#include "testing/gtest/include/gtest/gtest.h"
template <class AtomicType>
static void TestAtomicIncrement() {
// For now, we just test single threaded execution
// 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 {
AtomicType prev_word;
AtomicType count;
AtomicType next_word;
} s;
AtomicType prev_word_value, next_word_value;
memset(&prev_word_value, 0xFF, sizeof(AtomicType));
memset(&next_word_value, 0xEE, sizeof(AtomicType));
s.prev_word = prev_word_value;
s.count = 0;
s.next_word = next_word_value;
EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&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(base::subtle::NoBarrier_AtomicIncrement(&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(base::subtle::NoBarrier_AtomicIncrement(&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(base::subtle::NoBarrier_AtomicIncrement(&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(base::subtle::NoBarrier_AtomicIncrement(&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(base::subtle::NoBarrier_AtomicIncrement(&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(base::subtle::NoBarrier_AtomicIncrement(&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(base::subtle::NoBarrier_AtomicIncrement(&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(base::subtle::NoBarrier_AtomicIncrement(&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);
}
#define NUM_BITS(T) (sizeof(T) * 8)
template <class AtomicType>
static void TestCompareAndSwap() {
AtomicType value = 0;
AtomicType prev = base::subtle::NoBarrier_CompareAndSwap(&value, 0, 1);
EXPECT_EQ(1, value);
EXPECT_EQ(0, prev);
// Verify that CAS will *not* change "value" if it doesn't match the
// expected number. CAS will always return the actual value of the
// variable from before any change.
AtomicType fail = base::subtle::NoBarrier_CompareAndSwap(&value, 0, 2);
EXPECT_EQ(1, value);
EXPECT_EQ(1, fail);
// Use test value that has non-zero bits in both halves, more for testing
// 64-bit implementation on 32-bit platforms.
const AtomicType k_test_val = (static_cast<uint64_t>(1) <<
(NUM_BITS(AtomicType) - 2)) + 11;
value = k_test_val;
prev = base::subtle::NoBarrier_CompareAndSwap(&value, 0, 5);
EXPECT_EQ(k_test_val, value);
EXPECT_EQ(k_test_val, prev);
value = k_test_val;
prev = base::subtle::NoBarrier_CompareAndSwap(&value, k_test_val, 5);
EXPECT_EQ(5, value);
EXPECT_EQ(k_test_val, prev);
}
template <class AtomicType>
static void TestAtomicExchange() {
AtomicType value = 0;
AtomicType new_value = base::subtle::NoBarrier_AtomicExchange(&value, 1);
EXPECT_EQ(1, value);
EXPECT_EQ(0, new_value);
// Use test value that has non-zero bits in both halves, more for testing
// 64-bit implementation on 32-bit platforms.
const AtomicType k_test_val = (static_cast<uint64_t>(1) <<
(NUM_BITS(AtomicType) - 2)) + 11;
value = k_test_val;
new_value = base::subtle::NoBarrier_AtomicExchange(&value, k_test_val);
EXPECT_EQ(k_test_val, value);
EXPECT_EQ(k_test_val, new_value);
value = k_test_val;
new_value = base::subtle::NoBarrier_AtomicExchange(&value, 5);
EXPECT_EQ(5, value);
EXPECT_EQ(k_test_val, new_value);
}
template <class AtomicType>
static void TestAtomicIncrementBounds() {
// Test at rollover boundary between int_max and int_min
AtomicType test_val = (static_cast<uint64_t>(1) <<
(NUM_BITS(AtomicType) - 1));
AtomicType value = -1 ^ test_val;
AtomicType new_value = base::subtle::NoBarrier_AtomicIncrement(&value, 1);
EXPECT_EQ(test_val, value);
EXPECT_EQ(value, new_value);
base::subtle::NoBarrier_AtomicIncrement(&value, -1);
EXPECT_EQ(-1 ^ test_val, value);
// Test at 32-bit boundary for 64-bit atomic type.
test_val = static_cast<uint64_t>(1) << (NUM_BITS(AtomicType) / 2);
value = test_val - 1;
new_value = base::subtle::NoBarrier_AtomicIncrement(&value, 1);
EXPECT_EQ(test_val, value);
EXPECT_EQ(value, new_value);
base::subtle::NoBarrier_AtomicIncrement(&value, -1);
EXPECT_EQ(test_val - 1, value);
}
// Return an AtomicType with the value 0xa5a5a5..
template <class AtomicType>
static AtomicType TestFillValue() {
AtomicType val = 0;
memset(&val, 0xa5, sizeof(AtomicType));
return val;
}
// This is a simple sanity check that values are correct. Not testing
// atomicity
template <class AtomicType>
static void TestStore() {
const AtomicType kVal1 = TestFillValue<AtomicType>();
const AtomicType kVal2 = static_cast<AtomicType>(-1);
AtomicType value;
base::subtle::NoBarrier_Store(&value, kVal1);
EXPECT_EQ(kVal1, value);
base::subtle::NoBarrier_Store(&value, kVal2);
EXPECT_EQ(kVal2, value);
base::subtle::Acquire_Store(&value, kVal1);
EXPECT_EQ(kVal1, value);
base::subtle::Acquire_Store(&value, kVal2);
EXPECT_EQ(kVal2, value);
base::subtle::Release_Store(&value, kVal1);
EXPECT_EQ(kVal1, value);
base::subtle::Release_Store(&value, kVal2);
EXPECT_EQ(kVal2, value);
}
// This is a simple sanity check that values are correct. Not testing
// atomicity
template <class AtomicType>
static void TestLoad() {
const AtomicType kVal1 = TestFillValue<AtomicType>();
const AtomicType kVal2 = static_cast<AtomicType>(-1);
AtomicType value;
value = kVal1;
EXPECT_EQ(kVal1, base::subtle::NoBarrier_Load(&value));
value = kVal2;
EXPECT_EQ(kVal2, base::subtle::NoBarrier_Load(&value));
value = kVal1;
EXPECT_EQ(kVal1, base::subtle::Acquire_Load(&value));
value = kVal2;
EXPECT_EQ(kVal2, base::subtle::Acquire_Load(&value));
value = kVal1;
EXPECT_EQ(kVal1, base::subtle::Release_Load(&value));
value = kVal2;
EXPECT_EQ(kVal2, base::subtle::Release_Load(&value));
}
TEST(AtomicOpsTest, Inc) {
TestAtomicIncrement<base::subtle::Atomic32>();
TestAtomicIncrement<base::subtle::AtomicWord>();
}
TEST(AtomicOpsTest, CompareAndSwap) {
TestCompareAndSwap<base::subtle::Atomic32>();
TestCompareAndSwap<base::subtle::AtomicWord>();
}
TEST(AtomicOpsTest, Exchange) {
TestAtomicExchange<base::subtle::Atomic32>();
TestAtomicExchange<base::subtle::AtomicWord>();
}
TEST(AtomicOpsTest, IncrementBounds) {
TestAtomicIncrementBounds<base::subtle::Atomic32>();
TestAtomicIncrementBounds<base::subtle::AtomicWord>();
}
TEST(AtomicOpsTest, Store) {
TestStore<base::subtle::Atomic32>();
TestStore<base::subtle::AtomicWord>();
}
TEST(AtomicOpsTest, Load) {
TestLoad<base::subtle::Atomic32>();
TestLoad<base::subtle::AtomicWord>();
}
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