月度归档:2021年06月

捕获Qt Crash全图教程

关键点

  • 在main.cpp引入SetUnhandledExceptionFilter程序奔溃时生成dmp文件(代码)
  • Build release时包含debug信息(图)
  • Link dbghelp.lib库(图)
  • Build post自动复制qt依赖库(图)

Qt捕获Crash示例代码下载

Qt捕获Crash关键代码

main.cpp

#include <QtWidgets/QApplication>
#include <QMessageBox>
#include <QDateTime>
#include <QDir>
#include <QDebug>
#include "QtCrashApplication.h"
#include "main.h"

#ifdef Q_OS_WIN
#include <Windows.h>
#include <DbgHelp.h>
#endif

#ifdef Q_OS_WIN
static LONG WINAPI exceptionCallback(struct _EXCEPTION_POINTERS* exceptionInfo)
{
    QCoreApplication* app = QApplication::instance();

    QString savePath = app->applicationDirPath() + "dump/";
    qDebug() << "save path :" << savePath;
    QDir dir(savePath);
    if (!dir.exists() && !dir.mkpath(savePath)) {
        app->exit(E_UNEXPECTED);
        return EXCEPTION_EXECUTE_HANDLER;
    }

    savePath.append("assit_");
    savePath.append(QDateTime::currentDateTime().toString("yyyyMMddhhmmsszzz"));
    savePath.append(".dmp");

    HANDLE dump = CreateFileW(savePath.toStdWString().c_str(), GENERIC_WRITE,
        0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
    if (INVALID_HANDLE_VALUE == dump) {
        app->exit(E_UNEXPECTED);
        return EXCEPTION_EXECUTE_HANDLER;
    }

    MINIDUMP_EXCEPTION_INFORMATION miniDumpExceptionInfo;
    miniDumpExceptionInfo.ExceptionPointers = exceptionInfo;
    miniDumpExceptionInfo.ThreadId = GetCurrentThreadId();
    miniDumpExceptionInfo.ClientPointers = TRUE;
    DWORD idProcess = GetCurrentProcessId();
    MiniDumpWriteDump(GetCurrentProcess(), idProcess, dump,
        MiniDumpNormal, &miniDumpExceptionInfo, NULL, NULL);

    CloseHandle(dump);

    app->exit(E_UNEXPECTED);
    return EXCEPTION_EXECUTE_HANDLER;
}
#endif

int main(int argc, char* argv[])
{
    QApplication a(argc, argv);

#ifdef Q_OS_WIN
    SetUnhandledExceptionFilter(exceptionCallback);
#endif

    QtCrashApplication w;
    w.show();
    return a.exec();
}

QtCrashApplication.cpp

#include "QtCrashApplication.h"

QtCrashApplication::QtCrashApplication(QWidget *parent)
    : QMainWindow(parent)
{
    ui.setupUi(this);
    QObject::connect(ui.CrashButton, SIGNAL(clicked()), this, SLOT(crashMe()));
}

void QtCrashApplication::crashMe() {
    int i = 0;
    int n = 1 / i;
    ui.CrashButton->setText(QString(n));
}

新建项目

新建项目

配置项目

配置项目

项目配置向导

项目配置向导

项目配置向导2

项目配置向导2

编写会奔溃程序

编写会奔溃程序

程序运行截图

程序运行截图

点击运行后出现异常

点击运行后出现异常

自动生成依赖qt库

"$(QTDIR)\bin\windeployqt.exe" "$(OutDir.TrimEnd('\'))" --$(Configuration.toLower())

自动生成依赖qt库

自动生成依赖库

自动生成依赖库

生成release时生成debug信息

生成release时生成debug信息

包含dbghelp.lib库

包含dbghelp.lib库

查看生成记录

查看生成记录

查看结果

查看结果

参考

std::lock_guard — C++最简单的线程安全锁(避免死锁)

std::lock_guard 简单用法

#include <iostream>
#include <thread>
#include <mutex>

using namespace std;

int g_count = 0;
mutex g_mutex;

void increment()
{
    lock_guard<mutex> lock(g_mutex); // 开启后g_count总是可以输出20000,否则会少于20000
    ++g_count;
    this_thread::sleep_for(chrono::microseconds(2));
}

void run(int times)
{
    for (int i = 0; i < times; i++)
    {
        increment();
    }
}

int main()
{

    thread th1(run, 10000);
    thread th2(run, 10000);

    th1.join();
    th2.join();

    cout << g_count;

    return 0;
}

直接使用lock容易不对称导致死锁

#include <iostream>
#include <thread>
#include <mutex>

using namespace std;

int g_count = 0;
mutex g_mutex;

int increment1()
{
    g_mutex.lock();
    this_thread::sleep_for(chrono::microseconds(1));
    g_count++;
    g_mutex.unlock();
    return 0;
}

int increment2()
{
    g_mutex.lock();
    this_thread::sleep_for(chrono::microseconds(1));
    if (g_count > 11000)
    {
        return 0;
    }
    g_count++;
    g_mutex.unlock();
    return 0;
}

void run1(int times)
{
    for (int i = 0; i < times; i++)
    {
        increment1();
    }
}

void run2(int times)
{
    for (int i = 0; i < times; i++)
    {
        increment2();
    }
}

int main()
{

    thread th1(run1, 10000);
    thread th2(run2, 10000);

    th1.join();
    th2.join();

    cout << g_count;

    return 0;
}

使用lock_guard避免死锁

#include <iostream>
#include <thread>
#include <mutex>

using namespace std;

int g_count = 0;
mutex g_mutex;

int increment1()
{
    lock_guard<mutex> lock(g_mutex);
    this_thread::sleep_for(chrono::microseconds(1));
    g_count++;
    return 0;
}

int increment2()
{
    lock_guard<mutex> lock(g_mutex);
    this_thread::sleep_for(chrono::microseconds(1));
    g_count++;
    if (g_count > 11000)
    {
        return 0;
    }
    return 0;
}

void run1(int times)
{
    for (int i = 0; i < times; i++)
    {
        increment1();
    }
}

void run2(int times)
{
    for (int i = 0; i < times; i++)
    {
        increment2();
    }
}

int main()
{

    thread th1(run1, 10000);
    thread th2(run2, 10000);

    th1.join();
    th2.join();

    cout << g_count;

    return 0;
}

防止list下标越界,同样适用于map,set,vector等

#include <iostream>
#include <thread>
#include <mutex>
#include <list>

using namespace std;

class MonitorList
{

private:
    mutex g_mutex;
    list<int> g_list = {};

public:
    void push()
    {
        lock_guard<mutex> lock(g_mutex); // 不加会导致程序异常
        this_thread::sleep_for(chrono::microseconds(1));
        g_list.push_back(0);
    }

    void pop()
    {
        lock_guard<mutex> lock(g_mutex); // 不加会导致程序异常
        this_thread::sleep_for(chrono::microseconds(1));
        for (auto it = g_list.begin(); it != g_list.end(); ++it)
        {
            if (*it % 2 == 0)
            {
                it = g_list.erase(it);
            }
        }
    }
    int size()
    {
        return g_list.size();
    }
};

MonitorList g_MonitorList;

int main()
{

    thread th1([](int n)
               {
                   for (int i = 0; i < n; i++)
                   {
                       g_MonitorList.push();
                   }
               },
               10000);

    thread th2([](int n)
               {
                   for (int i = 0; i < n; i++)
                   {
                       g_MonitorList.pop();
                   }
               },
               3000);

    thread th3([](int n)
               {
                   for (int i = 0; i < n; i++)
                   {
                       g_MonitorList.pop();
                   }
               },
               3000);
    th1.join();
    th2.join();
    th3.join();

    cout << g_MonitorList.size() << endl;

    return 0;
}

使用ab,siege,jmeter进行快速JSON API性能测试

ab

ab -c 10 -n 100 -T 'application/json' -p test.json https://abc.com/test

siege

siege -c50 -t60S --content-type "application/json" 'http://domain.com/path/ POST {"ids": ["1","2","3"]}'

Jmeter

下载安装jmeter后,运行bin目录下的jmeterw.cmd即可。
file

待研究 plow

https://github.com/six-ddc/plow

  • 跨平台,无运行时依赖(基于 golang )
  • 高性能,比常见的 hey,ab,siege 等性能高不少(基本和 wrk 持平)
  • 终端实时展示性能数据,包括 RPS,延迟统计,百分位,Histogram 分布等
  • 支持实时网页展示,更全方面展示各时间点的压测数据

待研究 wrk

https://github.com/wg/wrk

Wrk 是一个现代的 HTTP 基准测试工具,能够在单个多核 CPU 上运行时产生大量负载。它将多线程设计与可伸缩的事件通知系统(如 epoll 和 kqueue)结合在一起。

可以使用lua脚本生成测试请求

待研究 hey

https://github.com/rakyll/hey

基于Go语言的ab替代工具

参考