80 lines
2.6 KiB
C++
80 lines
2.6 KiB
C++
// Copyright 2019 The MediaPipe 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
|
|
//
|
|
// 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.
|
|
|
|
#ifndef MEDIAPIPE_FRAMEWORK_LIFETIME_TRACKER_H_
|
|
#define MEDIAPIPE_FRAMEWORK_LIFETIME_TRACKER_H_
|
|
|
|
#include <atomic>
|
|
|
|
#include "absl/memory/memory.h"
|
|
#include "absl/synchronization/mutex.h"
|
|
|
|
namespace mediapipe {
|
|
|
|
// This class can be used to create objects whose lifetime is tracked by a
|
|
// counter. This is useful for testing.
|
|
// There is a separate counter per LifetimeTracker instance, and it counts the
|
|
// number of LifetimeTracker::Object instances created by that tracker.
|
|
// Therefore, you can use a single tracker with multiple objects to track
|
|
// overall behavior; or you can use separate trackers, with one object each, if
|
|
// you need to track each object's lifetime separately.
|
|
class LifetimeTracker {
|
|
public:
|
|
class Object {
|
|
public:
|
|
explicit Object(LifetimeTracker* tracker) : tracker_(tracker) {
|
|
absl::MutexLock lock(&tracker_->mutex_);
|
|
++tracker_->live_count_;
|
|
}
|
|
~Object() {
|
|
absl::MutexLock lock(&tracker_->mutex_);
|
|
--tracker_->live_count_;
|
|
}
|
|
|
|
private:
|
|
LifetimeTracker* const tracker_;
|
|
};
|
|
|
|
// Creates and returns a new tracked object.
|
|
std::unique_ptr<Object> MakeObject() {
|
|
return absl::make_unique<Object>(this);
|
|
}
|
|
|
|
// Returns the number of tracked objects currently alive.
|
|
int live_count() {
|
|
absl::MutexLock lock(&mutex_);
|
|
return live_count_;
|
|
}
|
|
|
|
// Waits for all instances of Object to be destroyed / live_count to reach
|
|
// zero. Returns true if this occurred within the timeout, false otherwise.
|
|
bool WaitForAllObjectsToDie(
|
|
absl::Duration timeout = absl::InfiniteDuration()) {
|
|
// Condition takes a function pointer. Prefixing the lambda with a +
|
|
// resolves it to a pointer.
|
|
absl::Condition check_count(
|
|
+[](int* value) { return *value == 0; }, &live_count_);
|
|
absl::MutexLock lock(&mutex_);
|
|
return mutex_.AwaitWithTimeout(check_count, timeout);
|
|
}
|
|
|
|
private:
|
|
absl::Mutex mutex_;
|
|
int live_count_ ABSL_GUARDED_BY(mutex_) = 0;
|
|
};
|
|
|
|
} // namespace mediapipe
|
|
|
|
#endif // MEDIAPIPE_FRAMEWORK_LIFETIME_TRACKER_H_
|