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// Copyright (c) 2012 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/containers/stack_container.h"
#include <stddef.h>
#include <algorithm>
#include "base/memory/ref_counted.h"
#include "build/build_config.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace base {
namespace {
class Dummy : public base::RefCounted<Dummy> {
public:
explicit Dummy(int* alive) : alive_(alive) {
++*alive_;
}
private:
friend class base::RefCounted<Dummy>;
~Dummy() {
--*alive_;
}
int* const alive_;
};
} // namespace
TEST(StackContainer, Vector) {
const int stack_size = 3;
StackVector<int, stack_size> vect;
const int* stack_buffer = &vect.stack_data().stack_buffer()[0];
// The initial |stack_size| elements should appear in the stack buffer.
EXPECT_EQ(static_cast<size_t>(stack_size), vect.container().capacity());
for (int i = 0; i < stack_size; i++) {
vect.container().push_back(i);
EXPECT_EQ(stack_buffer, &vect.container()[0]);
EXPECT_TRUE(vect.stack_data().used_stack_buffer_);
}
// Adding more elements should push the array onto the heap.
for (int i = 0; i < stack_size; i++) {
vect.container().push_back(i + stack_size);
EXPECT_NE(stack_buffer, &vect.container()[0]);
EXPECT_FALSE(vect.stack_data().used_stack_buffer_);
}
// The array should still be in order.
for (int i = 0; i < stack_size * 2; i++)
EXPECT_EQ(i, vect.container()[i]);
// Resize to smaller. Our STL implementation won't reallocate in this case,
// otherwise it might use our stack buffer. We reserve right after the resize
// to guarantee it isn't using the stack buffer, even though it doesn't have
// much data.
vect.container().resize(stack_size);
vect.container().reserve(stack_size * 2);
EXPECT_FALSE(vect.stack_data().used_stack_buffer_);
// Copying the small vector to another should use the same allocator and use
// the now-unused stack buffer. GENERALLY CALLERS SHOULD NOT DO THIS since
// they have to get the template types just right and it can cause errors.
std::vector<int, StackAllocator<int, stack_size> > other(vect.container());
EXPECT_EQ(stack_buffer, &other.front());
EXPECT_TRUE(vect.stack_data().used_stack_buffer_);
for (int i = 0; i < stack_size; i++)
EXPECT_EQ(i, other[i]);
}
TEST(StackContainer, VectorDoubleDelete) {
// Regression testing for double-delete.
typedef StackVector<scoped_refptr<Dummy>, 2> Vector;
typedef Vector::ContainerType Container;
Vector vect;
int alive = 0;
scoped_refptr<Dummy> dummy(new Dummy(&alive));
EXPECT_EQ(alive, 1);
vect->push_back(dummy);
EXPECT_EQ(alive, 1);
Dummy* dummy_unref = dummy.get();
dummy = nullptr;
EXPECT_EQ(alive, 1);
Container::iterator itr = std::find(vect->begin(), vect->end(), dummy_unref);
EXPECT_EQ(itr->get(), dummy_unref);
vect->erase(itr);
EXPECT_EQ(alive, 0);
// Shouldn't crash at exit.
}
namespace {
template <size_t alignment>
class AlignedData {
public:
AlignedData() { memset(data_, 0, alignment); }
~AlignedData() = default;
alignas(alignment) char data_[alignment];
};
} // anonymous namespace
#define EXPECT_ALIGNED(ptr, align) \
EXPECT_EQ(0u, reinterpret_cast<uintptr_t>(ptr) & (align - 1))
TEST(StackContainer, BufferAlignment) {
StackVector<wchar_t, 16> text;
text->push_back(L'A');
EXPECT_ALIGNED(&text[0], alignof(wchar_t));
StackVector<double, 1> doubles;
doubles->push_back(0.0);
EXPECT_ALIGNED(&doubles[0], alignof(double));
StackVector<AlignedData<16>, 1> aligned16;
aligned16->push_back(AlignedData<16>());
EXPECT_ALIGNED(&aligned16[0], 16);
#if !defined(__GNUC__) || defined(ARCH_CPU_X86_FAMILY)
// It seems that non-X86 gcc doesn't respect greater than 16 byte alignment.
// See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33721 for details.
// TODO(sbc):re-enable this if GCC starts respecting higher alignments.
StackVector<AlignedData<256>, 1> aligned256;
aligned256->push_back(AlignedData<256>());
EXPECT_ALIGNED(&aligned256[0], 256);
#endif
}
template class StackVector<int, 2>;
template class StackVector<scoped_refptr<Dummy>, 2>;
} // namespace base