Hmm, forgive my ignorance, but I don't understand how they can be double-freed. Wouldn't invokePPP(window, NULL, callback) return null if it has been freed?
Anyway. I'm able to reproduce this phenomenon in the "get started example", simply by adding the same callbacks that I'm using. This causes a JVM crash for me. Maybe I'm missing something?
import org.lwjgl.*;
import org.lwjgl.glfw.*;
import org.lwjgl.opengl.*;
import org.lwjgl.system.*;
import java.nio.*;
import static org.lwjgl.glfw.Callbacks.*;
import static org.lwjgl.glfw.GLFW.*;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.system.MemoryStack.*;
import static org.lwjgl.system.MemoryUtil.*;
public class Test {
// The window handle
private long window;
private GLFWKeyCallback keyCallback;
private GLFWMouseButtonCallback mouseCallback;
private GLFWScrollCallback scrollCallback;
public void run() {
System.out.println("Hello LWJGL " + Version.getVersion() + "!");
init();
loop();
// Free the window callbacks and destroy the window
keyCallback.free();
mouseCallback.free();
scrollCallback.free();
glfwFreeCallbacks(window);
glfwDestroyWindow(window);
// Terminate GLFW and free the error callback
glfwTerminate();
glfwSetErrorCallback(null).free();
}
private void setupCallbacks(long window) {
keyCallback = new GLFWKeyCallback() {
@Override
public void invoke(long window, int key, int arg2, int action, int arg4) {
if ( key == GLFW_KEY_ESCAPE && action == GLFW_RELEASE )
glfwSetWindowShouldClose(window, true); // We will detect this in the rendering loop
}
}; glfwSetKeyCallback(window, keyCallback);
mouseCallback = new GLFWMouseButtonCallback() {
@Override
public void invoke(long window, int button, int action, int mods) {
System.out.println("click!");
}
};
glfwSetMouseButtonCallback(window, mouseCallback);
scrollCallback = new GLFWScrollCallback() {
@Override
public void invoke(long window, double xoffset, double yoffset) {
System.out.println("scroll!");
}
};
glfwSetScrollCallback(window, scrollCallback);
}
private void init() {
// Setup an error callback. The default implementation
// will print the error message in System.err.
GLFWErrorCallback.createPrint(System.err).set();
// Initialize GLFW. Most GLFW functions will not work before doing this.
if ( !glfwInit() )
throw new IllegalStateException("Unable to initialize GLFW");
// Configure GLFW
glfwDefaultWindowHints(); // optional, the current window hints are already the default
glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE); // the window will stay hidden after creation
glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE); // the window will be resizable
// Create the window
window = glfwCreateWindow(300, 300, "Hello World!", NULL, NULL);
if ( window == NULL )
throw new RuntimeException("Failed to create the GLFW window");
setupCallbacks(window);
// Setup a key callback. It will be called every time a key is pressed, repeated or released.
// glfwSetKeyCallback(window, (window, key, scancode, action, mods) -> {
// if ( key == GLFW_KEY_ESCAPE && action == GLFW_RELEASE )
// glfwSetWindowShouldClose(window, true); // We will detect this in the rendering loop
// });
// Get the thread stack and push a new frame
try ( MemoryStack stack = stackPush() ) {
IntBuffer pWidth = stack.mallocInt(1); // int*
IntBuffer pHeight = stack.mallocInt(1); // int*
// Get the window size passed to glfwCreateWindow
glfwGetWindowSize(window, pWidth, pHeight);
// Get the resolution of the primary monitor
GLFWVidMode vidmode = glfwGetVideoMode(glfwGetPrimaryMonitor());
// Center the window
glfwSetWindowPos(
window,
(vidmode.width() - pWidth.get(0)) / 2,
(vidmode.height() - pHeight.get(0)) / 2
);
} // the stack frame is popped automatically
// Make the OpenGL context current
glfwMakeContextCurrent(window);
// Enable v-sync
glfwSwapInterval(1);
// Make the window visible
glfwShowWindow(window);
}
private void loop() {
// This line is critical for LWJGL's interoperation with GLFW's
// OpenGL context, or any context that is managed externally.
// LWJGL detects the context that is current in the current thread,
// creates the GLCapabilities instance and makes the OpenGL
// bindings available for use.
GL.createCapabilities();
// Set the clear color
glClearColor(1.0f, 0.0f, 0.0f, 0.0f);
// Run the rendering loop until the user has attempted to close
// the window or has pressed the ESCAPE key.
while ( !glfwWindowShouldClose(window) ) {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // clear the framebuffer
glfwSwapBuffers(window); // swap the color buffers
// Poll for window events. The key callback above will only be
// invoked during this call.
glfwPollEvents();
}
}
public static void main(String[] args) {
new Test().run();
}
}