phs_v1.0.1.0/commonlibrary/c_utils/docs/zh-cn/c-utils-guide-safe_block_queue.md

线程安全阻塞队列

概述

简介

​线程安全阻塞队列SafeBlockQueue类，提供阻塞和非阻塞版的入队入队和出队接口，并提供可最追踪任务完成状态的的SafeBlockQueueTracking类。

#include <safe_block_queue.h>

涉及功能

接口说明

OHOS::SafeBlockQueue

返回值	名称
	SafeBlockQueue(int capacity) 构造函数
	virtual ~SafeBlockQueue() 析构函数
void	virtual Push(T const& elem) 入队操作(阻塞版)
bool	virtual PushNoWait(T const& elem) 入队操作(非阻塞版)
T	Pop() 出队操作(阻塞版)
bool	PopNotWait(T& outtask) 出队操作(非阻塞版)
unsigned int	Size() 获取队列容量
bool	IsEmpty() 队列判空
bool	IsFull() 队列判满

OHOS::SafeBlockQueueTracking

class SafeBlockQueueTracking : public SafeBlockQueue

返回值	名称
explicit	SafeBlockQueueTracking(int capacity) 构造函数
	virtual ~SafeBlockQueueTracking() 析构函数
void	virtual Push(T const& elem) 入队操作(阻塞版)
bool	virtual PushNoWait(T const& elem) 入队操作(非阻塞版)
bool	OneTaskDone() 一个任务完成时的响应函数
void	Join() 等待未完成队列
int	GetUnfinishTaskNum() 获取未完成任务数

使用示例

1. 示例代码(伪代码)

• SafeBlockQueue的示例代码

#include <thread>
#include <functional>
#include <iostream>
#include "../include/safe_block_queue.h"

using namespace OHOS;
using namespace std;

constexpr int SIZE = 10;

class ProductsLine
{
public:
    ProductsLine(int maxSize) : que(maxSize) {}

    void Produce()
    {
        for (int i = 0; i < SIZE + 1; i++) {
            que.Push(i);
            cout << "Add " << i << " to the line" << endl;
        }
    }

    void Consume()
    {
        for (int i = 0; i < SIZE + 1; i++) {
            int out = que.Pop();
            cout << "Get " << out << " from the line" << endl;
        }
    }

    int remains()
    {
        return que.Size();
    }

private:
    SafeBlockQueue<int> que;
};

int main()
{
    ProductsLine line(SIZE);

    thread producer(bind(&ProductsLine::Produce, ref(line)));
    this_thread::sleep_for(chrono::milliseconds(1));

    thread consumer(bind(&ProductsLine::Consume, ref(line)));
    this_thread::sleep_for(chrono::milliseconds(1));

    producer.join();
    consumer.join();

    if (line.remains()==0) {
         cout << line.remains() << " elements remains in the queue. Synchronizing success." <<endl;
    }
}

• SafeBlockQueueTracking的示例代码

#include <thread>
#include <functional>
#include <iostream>
#include "../include/safe_block_queue.h"

using namespace OHOS;
using namespace std;

constexpr int SIZE = 10;

class ProductsLine
{
public:
    ProductsLine(int maxSize) : que(maxSize) {}

    void Produce()
    {
        for (int i = 0; i < SIZE + 1; i++) {
            que.Push(i);
            cout << "Add " << i << " to the line" << endl;
        }
    }

    void Consume()
    {
        for (int i = 0; i < SIZE + 1; i++) {
            int out = que.Pop();
            cout << "Get " << out << " from the line" << endl;
            que.OneTaskDone();
        }
    }

    void Join()
    {
        que.Join();
    }

    int UnfinishTaskNum()
    {
        return que.GetUnfinishTaskNum();
    }

private:
    SafeBlockQueueTracking<int> que;
};

int main()
{
    ProductsLine line(SIZE);

    thread producer(bind(&ProductsLine::Produce, ref(line)));
    this_thread::sleep_for(chrono::milliseconds(1));

    thread consumer(bind(&ProductsLine::Consume, ref(line)));
    this_thread::sleep_for(chrono::milliseconds(1));

    line.Join();

    producer.join();
    consumer.join();

    if (line.UnfinishTaskNum()==0) {
         cout << line.UnfinishTaskNum() << " elements remains in the queue. Synchronizing success." <<endl;
    }
}

2. 测试用例编译运行方法

• 测试用例代码参见base/test/unittest/common/utils_safe_block_queue_test.cpp 和 base/test/unittest/common/utils_safe_block_queue_tracking.cpp

• 使用开发者自测试框架，使用方法参见：开发自测试执行框架-测试用例执行

• 使用以下具体命令以运行safe_block_queue.h对应测试用例

run -t UT -tp utils -ts UtilsSafeBlockQueueTest

# or

run -t UT -tp utils -ts UtilsSafeBlockQueueTrackingTest

常见问题