From ee2f3c09788862612219acd93cec3d8d619cc7d1 Mon Sep 17 00:00:00 2001
From: jocelyn <jocelyn+git@yggdras.dyndns.org>
Date: Thu, 5 Mar 2009 21:45:58 +0100
Subject: [PATCH] Replace g_thread by g_thread_pool

All g_thread are replaced by a single g_thread_pool, which gives the ability to
easily limit the number of running threads, and will make it possible to wait
for all threads to finish correctly before exisiting viking.
---
 src/background.c   | 28 +++++++++++++++++++---------
 src/background.h   |  1 +
 src/vikmapslayer.c |  7 +++++--
 3 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/src/background.c b/src/background.c
index 624d78b..b9ca150 100644
--- a/src/background.c
+++ b/src/background.c
@@ -25,6 +25,8 @@
 #include "vikstatus.h"
 #include "background.h"
 
+static GThreadPool *thread_pool = NULL;
+
 static GtkWidget *bgwindow = NULL;
 static GtkWidget *bgtreeview = NULL;
 static GtkListStore *bgstore = NULL;
@@ -55,7 +57,7 @@ static void background_thread_update ()
   g_slist_foreach ( statusbars_to_update, (GFunc) a_background_update_status, buf );
 }
 
-void a_background_thread_progress ( gpointer callbackdata, gdouble fraction )
+int a_background_thread_progress ( gpointer callbackdata, gdouble fraction )
 {
   gpointer *args = (gpointer *) callbackdata;
   a_background_testcancel ( callbackdata );
@@ -65,7 +67,7 @@ void a_background_thread_progress ( gpointer callbackdata, gdouble fraction )
 
   args[6] = GINT_TO_POINTER(GPOINTER_TO_INT(args[6])-1);
   bgitemcount--;
-  background_thread_update();
+  return background_thread_update();
 }
 
 static void thread_die ( gpointer args[6] )
@@ -82,11 +84,9 @@ static void thread_die ( gpointer args[6] )
 
   g_free ( args[5] ); /* free iter */
   g_free ( args );
-
-  g_thread_exit ( NULL );
 }
 
-void a_background_testcancel ( gpointer callbackdata )
+int a_background_testcancel ( gpointer callbackdata )
 {
   gpointer *args = (gpointer *) callbackdata;
   if ( args[0] )
@@ -94,11 +94,11 @@ void a_background_testcancel ( gpointer callbackdata )
     vik_thr_free_func cleanup = args[4];
     if ( cleanup )
       cleanup ( args[2] );
-    thread_die( args );
+    return -1;
   }
+  return 0;
 }
-
-void thread_helper ( gpointer args[6] )
+void thread_helper ( gpointer args[6], gpointer user_data )
 {
   /* unpack args */
   vik_thr_func func = args[1];
@@ -141,7 +141,7 @@ void a_background_thread ( GtkWindow *parent, const gchar *message, vik_thr_func
 		       -1 );
 
   /* run the thread in the background */
-  g_thread_create( (GThreadFunc) thread_helper, args, FALSE, NULL );
+  g_thread_pool_push( thread_pool, args, NULL );
 }
 
 void a_background_show_window ()
@@ -194,6 +194,10 @@ static void bgwindow_response (GtkDialog *dialog, gint arg1 )
 
 void a_background_init()
 {
+  /* initialize thread pool */
+  gint max_threads = 10;  /* limit maximum number of threads running at one time */
+  thread_pool = g_thread_pool_new ( (GFunc) thread_helper, NULL, max_threads, FALSE, NULL );
+
   GtkCellRenderer *renderer;
   GtkTreeViewColumn *column;
   GtkWidget *scrolled_window;
@@ -232,6 +236,12 @@ void a_background_init()
 
 }
 
+void a_background_uninit()
+{
+  /* wait until all running threads stop */
+  g_thread_pool_free ( thread_pool, TRUE, TRUE );
+}
+
 void a_background_add_status(VikStatusbar *vs)
 {
   statusbars_to_update = g_slist_prepend(statusbars_to_update,vs);
diff --git a/src/background.h b/src/background.h
index 6bbb49f..09af6b1 100644
--- a/src/background.h
+++ b/src/background.h
@@ -36,6 +36,7 @@ void a_background_thread_progress ( gpointer callbackdata, gdouble fraction );
 void a_background_testcancel ( gpointer callbackdata );
 void a_background_show_window ();
 void a_background_init ();
+void a_background_uninit ();
 void a_background_add_status(VikStatusbar *vs);
 void a_background_remove_status(VikStatusbar *vs);
 
diff --git a/src/vikmapslayer.c b/src/vikmapslayer.c
index 5668757..934da6e 100644
--- a/src/vikmapslayer.c
+++ b/src/vikmapslayer.c
@@ -778,7 +778,7 @@ static void weak_ref_cb(gpointer ptr, GObject * dead_vml)
   g_mutex_unlock(mdi->mutex);
 }
 
-static void map_download_thread ( MapDownloadInfo *mdi, gpointer threaddata )
+static int map_download_thread ( MapDownloadInfo *mdi, gpointer threaddata )
 {
   guint donemaps = 0;
   gint x, y;
@@ -793,7 +793,9 @@ static void map_download_thread ( MapDownloadInfo *mdi, gpointer threaddata )
                      mdi->mapcoord.scale, mdi->mapcoord.z, x, y );
 
       donemaps++;
-      a_background_thread_progress ( threaddata, ((gdouble)donemaps) / mdi->mapstoget ); /* this also calls testcancel */
+      int res = a_background_thread_progress ( threaddata, ((gdouble)donemaps) / mdi->mapstoget ); /* this also calls testcancel */
+      if (res != 0)
+        return -1;
 
       if ( mdi->redownload == REDOWNLOAD_ALL)
         g_remove ( mdi->filename_buf );
@@ -850,6 +852,7 @@ static void map_download_thread ( MapDownloadInfo *mdi, gpointer threaddata )
   if (mdi->map_layer_alive)
     g_object_weak_unref(G_OBJECT(mdi->vml), weak_ref_cb, mdi);
   g_mutex_unlock(mdi->mutex); 
+  return 0;
 }
 
 static void mdi_cancel_cleanup ( MapDownloadInfo *mdi )
-- 
2.11.4.GIT