从线程调用时，GTK 代码挂起@gtk_container_add

Posted 2023-02-19

【中文标题】从线程调用时，GTK 代码挂起@gtk_container_add

【英文标题】：GTK code hangs @ gtk_container_add when called from thread

【发布时间】：2013-08-28 06:35:44

【问题描述】：

我是 GTK 和 GLIB 的新手 我只是想显示一个图像，然后调用一个 disptext 函数。 但是当直接从 main 调用 disptextpage 函数时它可以工作但是当我创建一个线程可以调用 disptextpage 它卡在

gtk_container_add(GTK_CONTAINER(window), textv);

永远不会回来。 我犯了什么错误

请指导：下面是示例代码：

    #include <stdio.h>
    #include <glib.h>
    #include <gtk/gtk.h>
    //#include "dispimage.h"
    #include <windows.h>
    #define sleep(n) Sleep(1000 * n)
    GtkWidget* window;
    void dispInit(int argc, char* argv[]);
    void dispInfoPage(char* fileName, int duration);


    gpointer main_callback(gpointer data)
    
        gtk_main();
        return 0;
    

    void dispInit(int argc, char* argv[])
    
        gdk_threads_init();
        gdk_threads_enter();
        printf("Initializing the display library\n");
        gtk_init(&argc, &argv);
        window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
        gtk_window_resize(GTK_WINDOW(window), 640, 480);
        gtk_window_set_default_size(GTK_WINDOW(window), 640, 480);
        gtk_widget_realize( window );
        gtk_window_set_decorated(GTK_WINDOW(window), FALSE);
        g_thread_create(main_callback, NULL, FALSE, NULL);
        gdk_threads_leave();
    

    void dispInfoPage(char* fileName, int duration)
    
        int index;
        gdk_threads_enter();
        printf("Initializing dispInfoPage\n");
        destroyWidget();
        printf("Initializing dispInfoPage1\n");
        GtkWidget *image;
        image = gtk_image_new_from_file(fileName);
        printf("Initializing dispInfoPage2\n");
        gtk_container_add(GTK_CONTAINER(window), image);
        gtk_widget_show(image);
        gtk_widget_show(window);
        printf("Initializing dispInfoPage4\n");
        printf("Initializing dispInfoPage5\n");
        gdk_threads_leave();
        printf("Initializing dispInfoPage6\n");
    

    void destroyWidget()
    
        GList *children, *iter;
        struct WidgetsAlive *temp, *prev, *next, *depTemp;
        children = gtk_container_get_children(GTK_CONTAINER(window));
        for(iter = children; iter != NULL; iter = g_list_next(iter))
            gtk_container_remove(GTK_CONTAINER(window),GTK_WIDGET(iter->data));
            printf("Deleting Widget\n");
        
        g_list_free(iter);
        g_list_free(children);

    


    int dispTextPage(char* fileName, int isJustifyCenter)
    
        int index;
        GtkWidget *textv;
        GdkWindow *textv_window;
        GdkPixmap *pixmap = NULL;
        GtkTextBuffer *textBuffer;
        gdk_threads_enter();
        GdkColor color;
        char debugBuf[128] =  '\0' ;
        char newfName[100]='\0';
        char ext[4]='\0';
        char temp[100]='\0';
        int i;
        FILE * fd;
        destroyWidget();
        textBuffer = gtk_text_buffer_new(NULL);
        textv = gtk_text_view_new_with_buffer(textBuffer);
        gtk_text_view_set_left_margin(GTK_TEXT_VIEW(textv), 22);
        gtk_text_view_set_right_margin(GTK_TEXT_VIEW(textv), 20);
        gtk_text_view_set_pixels_above_lines(GTK_TEXT_VIEW(textv),1);
        gtk_text_view_set_wrap_mode(GTK_TEXT_VIEW(textv), GTK_WRAP_CHAR);
        if (isJustifyCenter == 1)
        
            gtk_text_view_set_justification(GTK_TEXT_VIEW(textv), GTK_JUSTIFY_CENTER);
        
        else
        
            gtk_text_view_set_justification(GTK_TEXT_VIEW(textv), GTK_JUSTIFY_LEFT);
        
        gtk_text_view_set_editable(GTK_TEXT_VIEW(textv), FALSE);
        gtk_text_view_set_cursor_visible(GTK_TEXT_VIEW(textv), FALSE);
        printf("tttt0");
        gtk_container_add(GTK_CONTAINER(window), textv);
        printf("tttt1");
        textv_window = gtk_text_view_get_window (GTK_TEXT_VIEW (textv),
                                               GTK_TEXT_WINDOW_TEXT);
        gdk_color_parse ("#68604d", &color);
        pixmap = gdk_pixmap_create_from_xpm ((GdkDrawable *) textv_window, NULL,
                                           &color, fileName);
        gdk_window_set_back_pixmap (textv_window, pixmap, FALSE);
        g_object_unref(pixmap);

        textBuffer = gtk_text_view_get_buffer(GTK_TEXT_VIEW(textv));

        gtk_text_buffer_create_tag (textBuffer, "Red", "foreground", "Red", NULL);
        gtk_text_buffer_create_tag (textBuffer, "RedBold","foreground", "Red",NULL);
          gtk_text_buffer_create_tag(textBuffer, "gray_bg", "background", "gray", NULL);
          gtk_text_buffer_create_tag(textBuffer, "italic",  "style", PANGO_STYLE_ITALIC, NULL);
          gtk_text_buffer_create_tag(textBuffer, "bold","weight", PANGO_WEIGHT_BOLD, NULL);
        gtk_text_buffer_create_tag (textBuffer, "RedFontWeight", "weight", 1000,NULL);
        gtk_text_buffer_create_tag (textBuffer, "RedBoldFontWeight","weight", 1000,NULL);
        gtk_widget_show(textv);
        gtk_widget_show(window);
        gdk_threads_leave();
        return index;
    

    void *fsmThread_RunFunction()
    
        int pollMsgRetVal = -1;
        printf("Now enter into for image");
        dispInfoPage("../images/givefp.gif",1);
        sleep(5);
        dispInfoPage("../images/bootup.gif",1);
        sleep(5);
        dispInfoPage("../images/givefp.gif",1);
        sleep(5);
        dispInfoPage("../images/bootup.gif",1);
        sleep(5);
        printf("Now enter into for disptext");
        dispTextPage("",0);
        printf("Now exit for disptext");
    

    int main(int argc, char *argv[])
    
        GThread *fsmThreadId;
        GError *error = NULL;
        g_thread_init(NULL);
        dispInit(argc, argv);
        dispInfoPage("../images/bootup.gif",1);
        sleep(5);
        printf("Now creat ethread ");
        fsmThreadId = g_thread_create(fsmThread_RunFunction,NULL,TRUE,&error);
        if (error) 
          fflush(stderr);
          exit(1);
        
        g_thread_join(fsmThreadId);
        sleep(2);

        printf("ENd of main");
        return 0;
    

【参考方案1】：

所有 UI 操作/功能只能从一个线程调用。这是几乎所有（我所知道的）UI 库（Gtk+、Qt、wxWidgets...）的常见 API 使用要求

只是不要这样做。使用工作线程，使用g_idle_add 或g_timeout_add 并在那里进行（及时简短的）UI 修改。

【讨论】：

：跨线程之间通信的最佳方法是什么

@Ragav 他已经提到过：通常你会在非主线程中使用g_idle_add()。

g_idle_add 与 g_async_queue_push/pop 结合使用（后者可能不需要，取决于您的问题和实现方式）

@drahnr 感谢 :: g_idle_add :: 非常有帮助，现在正在检查处理参数的最佳方式...