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// 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
//
//
// 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.
#ifndef ABSL_CONTAINER_INTERNAL_TEST_INSTANCE_TRACKER_H_
#define ABSL_CONTAINER_INTERNAL_TEST_INSTANCE_TRACKER_H_
#include <cstdlib>
#include <ostream>
#include "absl/types/compare.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace test_internal {
// A type that counts number of occurrences of the type, the live occurrences of
// the type, as well as the number of copies, moves, swaps, and comparisons that
// have occurred on the type. This is used as a base class for the copyable,
// copyable+movable, and movable types below that are used in actual tests. Use
// InstanceTracker in tests to track the number of instances.
class BaseCountedInstance {
public:
explicit BaseCountedInstance(int x) : value_(x) {
++num_instances_;
++num_live_instances_;
}
BaseCountedInstance(const BaseCountedInstance& x)
: value_(x.value_), is_live_(x.is_live_) {
++num_instances_;
if (is_live_) ++num_live_instances_;
++num_copies_;
}
BaseCountedInstance(BaseCountedInstance&& x)
: value_(x.value_), is_live_(x.is_live_) {
x.is_live_ = false;
++num_instances_;
++num_moves_;
}
~BaseCountedInstance() {
--num_instances_;
if (is_live_) --num_live_instances_;
}
BaseCountedInstance& operator=(const BaseCountedInstance& x) {
value_ = x.value_;
if (is_live_) --num_live_instances_;
is_live_ = x.is_live_;
if (is_live_) ++num_live_instances_;
++num_copies_;
return *this;
}
BaseCountedInstance& operator=(BaseCountedInstance&& x) {
value_ = x.value_;
if (is_live_) --num_live_instances_;
is_live_ = x.is_live_;
x.is_live_ = false;
++num_moves_;
return *this;
}
bool operator==(const BaseCountedInstance& x) const {
++num_comparisons_;
return value_ == x.value_;
}
bool operator!=(const BaseCountedInstance& x) const {
++num_comparisons_;
return value_ != x.value_;
}
bool operator<(const BaseCountedInstance& x) const {
++num_comparisons_;
return value_ < x.value_;
}
bool operator>(const BaseCountedInstance& x) const {
++num_comparisons_;
return value_ > x.value_;
}
bool operator<=(const BaseCountedInstance& x) const {
++num_comparisons_;
return value_ <= x.value_;
}
bool operator>=(const BaseCountedInstance& x) const {
++num_comparisons_;
return value_ >= x.value_;
}
absl::weak_ordering compare(const BaseCountedInstance& x) const {
++num_comparisons_;
return value_ < x.value_
? absl::weak_ordering::less
: value_ == x.value_ ? absl::weak_ordering::equivalent
: absl::weak_ordering::greater;
}
int value() const {
if (!is_live_) std::abort();
return value_;
}
friend std::ostream& operator<<(std::ostream& o,
const BaseCountedInstance& v) {
return o << "[value:" << v.value() << "]";
}
// Implementation of efficient swap() that counts swaps.
static void SwapImpl(
BaseCountedInstance& lhs, // NOLINT(runtime/references)
BaseCountedInstance& rhs) { // NOLINT(runtime/references)
using std::swap;
swap(lhs.value_, rhs.value_);
swap(lhs.is_live_, rhs.is_live_);
++BaseCountedInstance::num_swaps_;
}
private:
friend class InstanceTracker;
int value_;
// Indicates if the value is live, ie it hasn't been moved away from.
bool is_live_ = true;
// Number of instances.
static int num_instances_;
// Number of live instances (those that have not been moved away from.)
static int num_live_instances_;
// Number of times that BaseCountedInstance objects were moved.
static int num_moves_;
// Number of times that BaseCountedInstance objects were copied.
static int num_copies_;
// Number of times that BaseCountedInstance objects were swapped.
static int num_swaps_;
// Number of times that BaseCountedInstance objects were compared.
static int num_comparisons_;
};
// Helper to track the BaseCountedInstance instance counters. Expects that the
// number of instances and live_instances are the same when it is constructed
// and when it is destructed.
class InstanceTracker {
public:
InstanceTracker()
: start_instances_(BaseCountedInstance::num_instances_),
start_live_instances_(BaseCountedInstance::num_live_instances_) {
ResetCopiesMovesSwaps();
}
~InstanceTracker() {
if (instances() != 0) std::abort();
if (live_instances() != 0) std::abort();
}
// Returns the number of BaseCountedInstance instances both containing valid
// values and those moved away from compared to when the InstanceTracker was
// constructed
int instances() const {
return BaseCountedInstance::num_instances_ - start_instances_;
}
// Returns the number of live BaseCountedInstance instances compared to when
// the InstanceTracker was constructed
int live_instances() const {
return BaseCountedInstance::num_live_instances_ - start_live_instances_;
}
// Returns the number of moves on BaseCountedInstance objects since
// construction or since the last call to ResetCopiesMovesSwaps().
int moves() const { return BaseCountedInstance::num_moves_ - start_moves_; }
// Returns the number of copies on BaseCountedInstance objects since
// construction or the last call to ResetCopiesMovesSwaps().
int copies() const {
return BaseCountedInstance::num_copies_ - start_copies_;
}
// Returns the number of swaps on BaseCountedInstance objects since
// construction or the last call to ResetCopiesMovesSwaps().
int swaps() const { return BaseCountedInstance::num_swaps_ - start_swaps_; }
// Returns the number of comparisons on BaseCountedInstance objects since
// construction or the last call to ResetCopiesMovesSwaps().
int comparisons() const {
return BaseCountedInstance::num_comparisons_ - start_comparisons_;
}
// Resets the base values for moves, copies, comparisons, and swaps to the
// current values, so that subsequent Get*() calls for moves, copies,
// comparisons, and swaps will compare to the situation at the point of this
// call.
void ResetCopiesMovesSwaps() {
start_moves_ = BaseCountedInstance::num_moves_;
start_copies_ = BaseCountedInstance::num_copies_;
start_swaps_ = BaseCountedInstance::num_swaps_;
start_comparisons_ = BaseCountedInstance::num_comparisons_;
}
private:
int start_instances_;
int start_live_instances_;
int start_moves_;
int start_copies_;
int start_swaps_;
int start_comparisons_;
};
// Copyable, not movable.
class CopyableOnlyInstance : public BaseCountedInstance {
public:
explicit CopyableOnlyInstance(int x) : BaseCountedInstance(x) {}
CopyableOnlyInstance(const CopyableOnlyInstance& rhs) = default;
CopyableOnlyInstance& operator=(const CopyableOnlyInstance& rhs) = default;
friend void swap(CopyableOnlyInstance& lhs, CopyableOnlyInstance& rhs) {
BaseCountedInstance::SwapImpl(lhs, rhs);
}
static bool supports_move() { return false; }
};
// Copyable and movable.
class CopyableMovableInstance : public BaseCountedInstance {
public:
explicit CopyableMovableInstance(int x) : BaseCountedInstance(x) {}
CopyableMovableInstance(const CopyableMovableInstance& rhs) = default;
CopyableMovableInstance(CopyableMovableInstance&& rhs) = default;
CopyableMovableInstance& operator=(const CopyableMovableInstance& rhs) =
default;
CopyableMovableInstance& operator=(CopyableMovableInstance&& rhs) = default;
friend void swap(CopyableMovableInstance& lhs, CopyableMovableInstance& rhs) {
BaseCountedInstance::SwapImpl(lhs, rhs);
}
static bool supports_move() { return true; }
};
// Only movable, not default-constructible.
class MovableOnlyInstance : public BaseCountedInstance {
public:
explicit MovableOnlyInstance(int x) : BaseCountedInstance(x) {}
MovableOnlyInstance(MovableOnlyInstance&& other) = default;
MovableOnlyInstance& operator=(MovableOnlyInstance&& other) = default;
friend void swap(MovableOnlyInstance& lhs, MovableOnlyInstance& rhs) {
BaseCountedInstance::SwapImpl(lhs, rhs);
}
static bool supports_move() { return true; }
};
} // namespace test_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_INTERNAL_TEST_INSTANCE_TRACKER_H_