gl_deletebuffers 不在单独的线程中工作

Question

在我的渲染应用程序中，如果我运行主循环中的渲染函数比一切正常，但如果我将渲染函数带到另一个线程，那么对象的析构函数将无法释放缓冲区.

当任何对象被销毁时

调用了对象的析构函数，但似乎 gl_deletebuffers 无法释放缓冲区。

我是怎么得出这个结论的

1) 当我在主循环中运行 everthing 并且如果我创建一个对象并且该对象的 VAO 编号为 1

2) 对象销毁后下一个对象VAO也被赋值1.

////////////////////////////////////////// //////////////////////////////////////////////// ////////////

1) 但是当渲染部分进入一个单独的线程时，VAO 数字会随着每个对象不断增加

2) 系统 Ram 内存也在不断增加，当我关闭应用程序时，只有内存被释放。

3) 当我删除一个对象时肯定会调用对象的析构函数，但似乎析构函数无法释放缓冲区。

 //#define GLEW_STATIC

#include <gl\glew.h>
#include <glfw3.h>
#include "TreeModel.h"
#include "ui_WavefrontRenderer.h"
#include <QtWidgets/QApplication>
#include <QMessageBox>
#include <thread>

#define FPS_WANTED 60

const double limitFPS = 1.0 / 50.0;

Container cont;
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;


void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow *window);
GLFWwindow* window = nullptr;
void RenderThread(WavefrontRenderer* w)
{       
    glfwMakeContextCurrent(window);
    GLenum GlewInitResult;
    glewExperimental = GL_TRUE;
    GlewInitResult = glewInit();
    if (GLEW_OK != GlewInitResult)   // Check if glew is initialized properly
    {
        QMessageBox msgBox;
        msgBox.setText("Not able to Initialize Glew");
        msgBox.exec();
        glfwTerminate();
    }

    if (window == NULL)
    {
        QMessageBox msgBox;
        msgBox.setText("Not able to create GL Window");
        msgBox.exec();
        glfwTerminate();
        //return -1;
    }

    w->InitData();  
    glEnable(GL_MULTISAMPLE);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glBlendEquation(GL_FUNC_ADD);   
    while (!glfwWindowShouldClose(window))
    {
        // input
        // -----
        processInput(window);
        // - Measure time   
        glClearColor(0.3, 0.3, 0.3, 0.0);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
        w->render(); // DO the Rendering        
        glfwSwapBuffers(window);
        glfwPollEvents();

    }   
    glfwTerminate();
    std::terminate();
}



int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    cont.SetName("RootItem");
    TreeModel* model = new TreeModel("RootElement", &cont);
    WavefrontRenderer w(model);
    w.show();
    glfwInit();
    glfwWindowHint(GLFW_RESIZABLE, GL_TRUE);
    glfwWindowHint(GLFW_SAMPLES, 4);
    window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "Renderer", nullptr, nullptr);   // Create the render 

window
    glfwMakeContextCurrent(0);
    std::thread renderThread(RenderThread, &w);
    renderThread.detach();  
    return a.exec();
    return 0;
}

Class 对象的定义

渲染函数w->render()调用对象的draw()函数

Base class 有一个虚拟析构函数。

#include "Triangle.h"
#include "qdebug.h"
#include "qmessagebox.h"

float verticesTriangle[] = {
    -50.0f, -50.0f, 0.0f,   0.0f , 0.0f,1.0f    ,0.0f, 0.0f,
     50.0f, -50.0f, 0.0f,   0.0f , 0.0f,1.0f    ,1.0f, 0.0f,
     0.0f,  50.0f, 0.0f,   0.0f, 0.0f,1.0f     ,0.5f, 1.0f
};

Triangle::Triangle() : Geometry("TRIANGLE", true)
{       
    this->isInited = 0;
    this->m_VBO = 0;
    this->m_VAO = 0;
    this->iNumsToDraw = 0;
    this->isChanged = true;
}

Triangle::Triangle(const Triangle& triangle) : Geometry( triangle )
{
    CleanUp();
    this->isInited = 0;
    this->m_VBO = 0;
    this->m_VAO = 0;
    this->iNumsToDraw = triangle.iNumsToDraw;
    this->isChanged = true;
    this->shader = ResourceManager::GetShader("BasicShader");
    iEntries = 3;
}

Triangle& Triangle::operator=(const Triangle& triangle)
{
    CleanUp();
    Geometry::operator=(triangle);
    this->isInited = 0;
    this->m_VBO = 0;
    this->m_VAO = 0;
    this->iNumsToDraw = triangle.iNumsToDraw;
    this->isChanged = true;
    this->shader = ResourceManager::GetShader("BasicShader");
    return (*this);
}

void Triangle::init()
{
    glGenVertexArrays(1, &m_VAO);
    glGenBuffers(1, &m_VBO);
    glBindVertexArray(m_VAO);
    glBindBuffer(GL_ARRAY_BUFFER, m_VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(verticesTriangle), verticesTriangle, GL_STATIC_DRAW);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    glEnableVertexAttribArray(1);
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
    glEnableVertexAttribArray(0);
    glEnableVertexAttribArray(2);
    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindVertexArray(0);
    isInited = true;
}

void Triangle::CleanUp()
{
    if (!this->isInited)
    {
        return;
    }
    if (this->m_VAO)
        glDeleteVertexArrays(1, &this->m_VAO);

    if (this->m_VBO)
        glDeleteBuffers(1, &this->m_VBO);

    this->isInited = false;
}

void Triangle::draw()
{
    if (isChanged)
    {
        init();
        isChanged = false;
    }
    this->shader.Use();
    glBindVertexArray(m_VAO);
    glDrawArrays(GL_TRIANGLES, 0, 3);
    glBindVertexArray(0);
}

Triangle::~Triangle()
{
    if (this->m_VAO)
        glDeleteVertexArrays(1, &this->m_VAO);

    if (this->m_VBO)
        glDeleteBuffers(1, &this->m_VBO);


    this->isInited = false;
}

Answer 1

OpenGL 上下文是线程本地状态：

在任何给定时间，每个线程只有一个或没有活动的 OpenGL 上下文。
在任何给定时间，每个 OpenGL 上下文都必须在没有线程或只有一个线程中处于活动状态。
OpenGL 上下文不会在线程之间自动迁移。

即如果您没有在当前处于活动状态的线程上明确取消相关 OpenGL 上下文的当前状态，并随后在您正在调用 glDeleteBuffers 的线程上使其处于活动状态，则对该线程的调用将无效；至少在您预期它会产生影响的上下文中。

gl_deletebuffers 不在单独的线程中工作

gl_deletebuffers not working in a separate thread

opengl

memory-leaks

glfw