C Memory Leak in GLFW

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1

2/2/2023

I’m working on a OpenGL project, and valgrind is detecting a memory leak from GLFW. I’m not sure what I’m doing wrong, but it occurs when I call glfwInit() from what I can tell. I’m calling glfwTerminate() at the end of the main function, so I don’t know why this is leaking.

(I’m using quite almost the “example” code for an OpenGL project.)



Valgrind log:

==784== Memcheck, a memory error detector
==784== Copyright (C) 2002-2022, and GNU GPL'd, by Julian Seward et al.
==784== Using Valgrind-3.19.0 and LibVEX; rerun with -h for copyright info
==784== Command: ./bin/OpenGL
==784==
==784==
==784== HEAP SUMMARY:
==784==     in use at exit: 12,336 bytes in 3 blocks
==784==   total heap usage: 46 allocs, 43 frees, 25,926 bytes allocated
==784==
==784== 4,096 bytes in 1 blocks are definitely lost in loss record 1 of 3
==784==    at 0x4847A73: calloc (vg_replace_malloc.c:1328)
==784==    by 0x52569A8: ???
==784==    by 0x5268834: ???
==784==    by 0x1239FD: _glfwConnectX11 (in /home/username/Documents/Source/OpenGL/bin/OpenGL)
==784==    by 0x11A72B: _glfwSelectPlatform (in /home/username/Documents/Source/OpenGL/bin/OpenGL)
==784==    by 0x114298: glfwInit (in /home/username/Documents/Source/OpenGL/bin/OpenGL)
==784==    by 0x10E459: main (main.c:18)
==784==
==784== 8,240 (64 direct, 8,176 indirect) bytes in 1 blocks are definitely lost in loss record 3 of 3
==784==    at 0x4842888: malloc (vg_replace_malloc.c:381)
==784==    by 0x5256B56: ???
==784==    by 0x5268834: ???
==784==    by 0x1239FD: _glfwConnectX11 (in /home/username/Documents/Source/OpenGL/bin/OpenGL)
==784==    by 0x11A72B: _glfwSelectPlatform (in /home/username/Documents/Source/OpenGL/bin/OpenGL)
==784==    by 0x114298: glfwInit (in /home/username/Documents/Source/OpenGL/bin/OpenGL)
==784==    by 0x10E459: main (main.c:18)
==784==
==784== LEAK SUMMARY:
==784==    definitely lost: 4,160 bytes in 2 blocks
==784==    indirectly lost: 8,176 bytes in 1 blocks
==784==      possibly lost: 0 bytes in 0 blocks
==784==    still reachable: 0 bytes in 0 blocks
==784==         suppressed: 0 bytes in 0 blocks
==784==
==784== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)

Example Code I’m using:

#include <glad/glad.h>
#include <GLFW/glfw3.h>

#include <stdio.h>

void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow *window);

// settings
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;


int main()
{
    // glfw: initialize and configure
    // ------------------------------
    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    // glfw window creation
    // --------------------
    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "OpenGL Window", NULL, NULL);
    if (window == NULL)
    {
        printf("Failed to create GLFW window\n");
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);
    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

    // glad: load all OpenGL function pointers
    // ---------------------------------------
    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
    {
        printf("Failed to initialize GLAD\n");
        return -1;
    }

    // uncomment this call to draw in wireframe polygons.
    //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

    // render loop
    // -----------
    while (!glfwWindowShouldClose(window))
    {
        // input
        // -----
        processInput(window);

        // rendering
        glClearColor(0.3f, 0.2f, 0.3f, 0.5f);
        glClear(GL_COLOR_BUFFER_BIT);

        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
        // -------------------------------------------------------------------------------
        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    // glfw: terminate, clearing all previously allocated GLFW resources.
    // ------------------------------------------------------------------
    glfwTerminate();
    return 0;
}

// process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
// ---------------------------------------------------------------------------------------------------------
void processInput(GLFWwindow* window)
{
    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
        glfwSetWindowShouldClose(window, 1);
}

// glfw: whenever the window size changed (by OS or user resize) this callback function executes
// ---------------------------------------------------------------------------------------------
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
    // make sure the viewport matches the new window dimensions; note that width and
    // height will be significantly larger than specified on retina displays.
    glViewport(0, 0, width, height);
}

Thanks.