Multiple Thread Progress Bar Control with gtk

Question

in my C program , download some files from the internet, im using a GTK progress bar to show the download progress.

i wanna if i download one file ,my app show one progress bar

if i download three files ,my app can show three progress bar. the rest can be done in the same manner.

i create UI with glade3. GtkTreeView have 3 columns

1. Name
2. Progress
3. Status

and i wrote some code , its can work but have some problem

if i download one file,app lonking not bad.

but if i download two files. app could not show twoprogress bar.

app just show two thread in one progress

How should I do solve it ?

progress.glade

and source code :

/*
gcc -Wall -g `pkg-config --cflags --libs gtk+-2.0 gmodule-export-2.0` -lcurl -lgthread-2.0  liststore.c -o liststore
 */
#include <stdio.h>
#include <gtk/gtk.h>
#include <glib.h>
#include <unistd.h>
#include <pthread.h>

#include <curl/curl.h>
#include <curl/types.h> /* new for v7 */
#include <curl/easy.h> /* new for v7 */

gchar *URL = "http://soundclash-records.co.uk/mp3s/upfull_rockers_never_gonna_let_you_down.mp3";

size_t my_write_func(void *ptr, size_t size, size_t nmemb, FILE *stream)
{
    return fwrite(ptr, size, nmemb, stream);
}

size_t my_read_func(void *ptr, size_t size, size_t nmemb, FILE *stream)
{
    return fread(ptr, size, nmemb, stream);
}

typedef struct _Data Data;
struct _Data
{
    GtkWidget *down; /* Down button */
    GtkWidget *tree; /* Tree view */
    gdouble progress;
};

enum
{
    STRING_COLUMN,
    INT_COLUMN,
    N_COLUMNS
};

gboolean set_download_progress(gpointer data)
{
    Data *treeview = (Data *)data;
    GtkListStore* store = GTK_LIST_STORE(gtk_tree_view_get_model(GTK_TREE_VIEW(treeview->tree)));
    GtkTreeIter iter;

    gtk_tree_model_get_iter_from_string (GTK_TREE_MODEL (store) ,
                                       &iter,
                                       g_strdup_printf ("%d",0));   
    gtk_list_store_set(store, &iter,
                       INT_COLUMN,treeview->progress, -1);

    return FALSE;
}

int my_progress_func(Data *data,
                     double t, /* dltotal */
                     double d, /* dlnow */
                     double ultotal,
                     double ulnow)
{
//  printf("%d / %d (%g %%)\n", d, t, d*100.0/t);
    gdk_threads_enter();
    gdouble progress;
    progress = d*100.0/t;
    data->progress = progress;
    g_idle_add(set_download_progress, data);

    gdk_threads_leave();
    return 0;
}

void *create_thread(void *data)
{
    Data *viewtree = (Data *)data;
    GtkTreeIter iter;

    GtkListStore* store = GTK_LIST_STORE(gtk_tree_view_get_model(GTK_TREE_VIEW(viewtree->tree)));
    gtk_list_store_append( store, &iter );


    g_print("url\n");
    CURL *curl;
    CURLcode res;
    FILE *outfile;
    gchar *url = URL;

    curl = curl_easy_init();
    if(curl)
    {
        outfile = fopen("test.curl", "w");
     if(outfile)
      g_print("curl\n");

        curl_easy_setopt(curl, CURLOPT_URL, url);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, outfile);
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, my_write_func);
        curl_easy_setopt(curl, CURLOPT_READFUNCTION, my_read_func);

        curl_easy_setopt(curl, CURLOPT_NOPROGRESS, FALSE);
        curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, my_progress_func);
        curl_easy_setopt(curl, CURLOPT_PROGRESSDATA, data);

        res = curl_easy_perform(curl);

        fclose(outfile);
        /* always cleanup */
        curl_easy_cleanup(curl);
    }
    g_object_unref( G_OBJECT( store ) );
    return NULL;
}


G_MODULE_EXPORT void
cb_add( GtkWidget *button,
         Data      *data )
{
    if (!g_thread_create(&create_thread, data, FALSE, NULL) != 0)
        g_warning("can't create the thread");
} 
int main(int argc, char **argv)
{
    GtkBuilder *builder;
    GtkWidget  *window;
    Data       *data;


    curl_global_init(CURL_GLOBAL_ALL);
    if( ! g_thread_supported() )
        g_thread_init( NULL );

    gdk_threads_init();
    gtk_init(&argc, &argv);

    data = g_slice_new( Data );

    /* Create builder */
    builder = gtk_builder_new();
    gtk_builder_add_from_file( builder, "progress.glade", NULL );

    window    = GTK_WIDGET( gtk_builder_get_object( builder, "window1" ) );
    data->down   = GTK_WIDGET( gtk_builder_get_object( builder, "down" ) );
    data->tree = GTK_WIDGET( gtk_builder_get_object( builder, "treeview" ) );

    gtk_builder_connect_signals( builder, data );
    g_object_unref( G_OBJECT( builder ) );

    gtk_widget_show( window );

    gtk_main();
    g_slice_free( Data, data );

    return 0;
}

=========================================================

Update : 12-11-09

/*
gcc -Wall -g `pkg-config --cflags --libs gtk+-2.0 gmodule-export-2.0 gthread-2.0 libcurl` liststore2.c -o liststore2
 */
#include <stdio.h>
#include <gtk/gtk.h>
#include <glib.h>
#include <unistd.h>
#include <pthread.h>

#include <curl/curl.h>
#include <curl/types.h> /* new for v7 */
#include <curl/easy.h> /* new for v7 */

gchar *URL = "http://soundclash-records.co.uk/mp3s/upfull_rockers_never_gonna_let_you_down.mp3";
static GHashTable* TreeRowReferences;
static GPrivate* current_data_key = NULL;

size_t my_write_func(void *ptr, size_t size, size_t nmemb, FILE *stream)
{
    return fwrite(ptr, size, nmemb, stream);
}

size_t my_read_func(void *ptr, size_t size, size_t nmemb, FILE *stream)
{
    return fread(ptr, size, nmemb, stream);
}

typedef struct _Data Data;
struct _Data
{
    GtkWidget *down; /* Down button */
    GtkWidget *tree; /* Tree view */
    gdouble progress;
};

enum
{
    STRING_COLUMN,
    INT_COLUMN,
    N_COLUMNS
};

gboolean set_download_progress(gpointer data)
{
    Data *treeview = (Data *)data;

    GtkListStore* store = GTK_LIST_STORE(gtk_tree_view_get_model(GTK_TREE_VIEW(treeview->tree)));
    GtkTreeIter iter;

    GtkTreeRowReference* reference = g_hash_table_lookup(TreeRowReferences,data);

    GtkTreePath* path = gtk_tree_row_reference_get_path(reference);

    gtk_tree_model_get_iter(GTK_TREE_MODEL(store), 
        &iter, path);

    gtk_list_store_set(store, &iter,
                       INT_COLUMN,treeview->progress, -1);

    gtk_tree_path_free (path);
    return FALSE;
}

int my_progress_func(Data *data,
             double t, /* dltotal */
             double d, /* dlnow */
             double ultotal,
             double ulnow)
{
    if(t == 0)
        return 0;
    data->progress = d*100.0/t;

    gdk_threads_enter();
    g_idle_add(set_download_progress, data);
    gdk_threads_leave();
    return 0;
}

void *create_thread(void *data)
{

    Data *current_treeview = g_private_get (current_data_key);

    if (!current_treeview)
    {
      current_treeview = g_new (Data, 1);
      current_treeview = (Data *)data;
      g_private_set (current_data_key, current_treeview);
      g_print("p %g\n",current_treeview->progress);
    }
    else{
     current_treeview = (Data *)data;
       g_print("c %g\n",current_treeview->progress);
    }

    g_print("url\n");
    CURL *curl;
    CURLcode res;
    FILE *outfile;
    gchar *url = URL;
    gdk_threads_enter();
    curl = curl_easy_init();
    if(curl)
    {
        outfile = fopen("test.curl", "w");
     if(outfile)
      g_print("curl\n");

        curl_easy_setopt(curl, CURLOPT_URL, url);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, outfile);
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, my_write_func);
        curl_easy_setopt(curl, CURLOPT_READFUNCTION, my_read_func);

        curl_easy_setopt(curl, CURLOPT_NOPROGRESS, FALSE);
        curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, my_progress_func);
        curl_easy_setopt(curl, CURLOPT_PROGRESSDATA, current_treeview);
     gdk_threads_leave();
        res = curl_easy_perform(curl);

        fclose(outfile);
        /* always cleanup */
        curl_easy_cleanup(curl);
    }
    return NULL;
}


G_MODULE_EXPORT void
cb_add( GtkWidget *button,
         Data      *data )
{    
    Data *current_download = (Data *)data;
    GtkTreeIter iter;
    GtkListStore* store = GTK_LIST_STORE(gtk_tree_view_get_model(GTK_TREE_VIEW(current_download->tree)));
    gtk_list_store_append( store, &iter );

    GtkTreeRowReference* reference = NULL;
    GtkTreePath* path = gtk_tree_model_get_path(GTK_TREE_MODEL(store), &iter);
    reference = gtk_tree_row_reference_new(GTK_TREE_MODEL(store), path);
    g_hash_table_insert(TreeRowReferences, current_download, reference);
    gtk_tree_path_free(path);

    if (!g_thread_create(&create_thread, current_download, FALSE, NULL) != 0)
        g_warning("can't create the thread");
} 

int main(int argc, char **argv)
{
    GtkBuilder *builder;
    GtkWidget  *window;
    Data       *data;


    curl_global_init(CURL_GLOBAL_ALL);
    if( ! g_thread_supported() )
        g_thread_init( NULL );

    gdk_threads_init();
    gtk_init(&argc, &argv);

    data = g_slice_new( Data );

    /* Create builder */
    builder = gtk_builder_new();
    gtk_builder_add_from_file( builder, "progress.glade", NULL );

    window    = GTK_WIDGET( gtk_builder_get_object( builder, "window1" ) );
    data->down   = GTK_WIDGET( gtk_builder_get_object( builder, "down" ) );
    data->tree = GTK_WIDGET( gtk_builder_get_object( builder, "treeview" ) );
    TreeRowReferences = g_hash_table_new(NULL, NULL);

    gtk_builder_connect_signals( builder, data );
    g_object_unref( G_OBJECT( builder ) );

    gdk_threads_enter();
    gtk_widget_show( window );
    gdk_threads_leave();

    gtk_main();
    g_slice_free( Data, data );

    return 0;
}

Answer 1

Here are my tips for getting your code to work:

1. If there's a pkg-config file for a library, like gthread or libcurl, then use that instead of mixing pkg-config calls and -l switches. This wasn't the problem, but it might give you problems later on. So compile your file like this:

   gcc -Wall -g `pkg-config --cflags --libs gtk+-2.0 gmodule-export-2.0 gthread-2.0 libcurl` liststore.c -o liststore
   

2. If using threads, always, always, always, wrap your call to gtk_main() in between gdk_threads_enter() and gdk_threads_leave(). This wasn't the problem either, but it definitely will give you problems later on.

3. Next step, eliminate all the warnings spewing all over the console. It's easier to spot a mistake when the warning it generates isn't lost in 50 other warnings. And those warnings do mean you're doing something wrong, so don't ignore them.

   a. The first warnings I got were complaining about NaNs. NaN stands for "not a number" and it's what you get when you divide by zero. The only division in your code is in my_progress_func() so probably CURL sometimes passes in zero as the dltotal parameter. If you check for that, it eliminates those warnings:

   int my_progress_func(Data *data,
                double t, /* dltotal */
                double d, /* dlnow */
                double ultotal,
                double ulnow)
   {
       if(t == 0)
           return 0;
       data->progress = d*100.0/t;
       gdk_threads_enter();
       g_idle_add(set_download_progress, data);
       gdk_threads_leave();
       return 0;
   }
   

   b. The next cause of warnings is the unref statement at the end of thread_create(). What you are doing is using gtk_tree_view_get_model() to get the model from the tree view, but that doesn't give you a reference to the model. So when you unref it, you are actually destroying the model while the tree view is still using it. Delete that statement, and all the warnings magically disappear. You don't need to unref the model at all. The tree view owns the only reference to it, and when the tree view gets destroyed it will unref the model automatically. That still isn't the problem though.

4. Now all that's out of the way, you can be certain the problem isn't being caused by some invalid pointer or thread problem. And it turns out to be something quite simple after all:

   gtk_tree_model_get_iter_from_string (GTK_TREE_MODEL (store) ,
                                        &iter,
                                        g_strdup_printf ("%d",0));
   

   Here, you are always getting an iter pointing to row number 0, i.e. the first row. And that's why all the download progress shows up in the first row. I would recommend using GPrivate to have a per-thread data structure with its own progress fraction, and a GtkTreeRowReference to the row you create when starting the thread. Get CURL to send that data structure to the callback. Don't use a GtkTreeIter or GtkTreePath to store the row. Instead, get your GtkTreeIter like this:

   gtk_tree_model_get_iter(gtk_tree_row_reference_get_model(row_reference), &iter, gtk_tree_row_reference_get_path(row_reference));
   

Good luck.