blob: f669af1dcd2f5addae64ca8cf556343e2210cc10 [file] [log] [blame]
// Copyright 2016 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.
#ifndef BASE_TASK_SCHEDULER_SCHEDULER_WORKER_THREAD_STACK_H_
#define BASE_TASK_SCHEDULER_SCHEDULER_WORKER_THREAD_STACK_H_
#include <stddef.h>
#include <vector>
#include "base/base_export.h"
#include "base/macros.h"
namespace base {
namespace internal {
class SchedulerWorkerThread;
// A stack of SchedulerWorkerThreads. Supports removal of arbitrary
// SchedulerWorkerThreads. DCHECKs when a SchedulerWorkerThread is inserted
// multiple times. SchedulerWorkerThreads are not owned by the stack. Push() is
// amortized O(1). Pop(), Size() and Empty() are O(1). Remove is O(n). This
// class is NOT thread-safe.
class BASE_EXPORT SchedulerWorkerThreadStack {
public:
SchedulerWorkerThreadStack();
~SchedulerWorkerThreadStack();
// Inserts |worker_thread| at the top of the stack. |worker_thread| must not
// already be on the stack.
void Push(SchedulerWorkerThread* worker_thread);
// Removes the top SchedulerWorkerThread from the stack and returns it.
// Returns nullptr if the stack is empty.
SchedulerWorkerThread* Pop();
// Removes |worker_thread| from the stack.
void Remove(const SchedulerWorkerThread* worker_thread);
// Returns the number of SchedulerWorkerThreads on the stack.
size_t Size() const { return stack_.size(); }
// Returns true if the stack is empty.
bool IsEmpty() const { return stack_.empty(); }
private:
std::vector<SchedulerWorkerThread*> stack_;
DISALLOW_COPY_AND_ASSIGN(SchedulerWorkerThreadStack);
};
} // namespace internal
} // namespace base
#endif // BASE_TASK_SCHEDULER_SCHEDULER_WORKER_THREAD_STACK_H_