Fix memory leak when viewing many files

src/main.c

@@ -41,6 +41,7 @@
 
 #include <string.h>
 #include <stdlib.h>
+#include <malloc.h>
 #include <glib/gi18n.h>
 
 static XviewerStartupFlags flags;
@@ -96,6 +97,17 @@ main (int argc, char **argv)
 	GError *error = NULL;
 	GOptionContext *ctx;
 
+	/* Pin the mmap threshold so that large image buffers (which are
+	 * typically several MB and can vary a lot in size while browsing)
+	 * always go through mmap/munmap, guaranteeing their memory is
+	 * released back to the OS immediately on free. Without this,
+	 * glibc's malloc can grow its heap arena to fit a peak allocation
+	 * and never shrink it back, causing RSS to climb and plateau at
+	 * high-water marks that never come back down while browsing many
+	 * large images in succession. */
+	mallopt (M_MMAP_THRESHOLD, 128 * 1024);
+	mallopt (M_MMAP_MAX, 65536);
+
 	bindtextdomain (GETTEXT_PACKAGE, XVIEWER_LOCALE_DIR);
 	bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
 	textdomain (GETTEXT_PACKAGE);

src/xviewer-image.c

@@ -1302,6 +1302,7 @@ xviewer_image_real_load (XviewerImage *img,
 
 		if (gdk_pixbuf_animation_is_static_image (priv->anim)) {
 			priv->image = gdk_pixbuf_animation_get_static_image (priv->anim);
+			g_object_unref (priv->anim);
 			priv->anim = NULL;
 		} else {
 			priv->anim_iter = gdk_pixbuf_animation_get_iter (priv->anim,NULL);

src/xviewer-jobs.c

@@ -279,12 +279,16 @@ xviewer_job_cancel (XviewerJob *job)
 	g_object_ref (job);
 
 	/* check if job was cancelled previously */
-	if (job->cancelled)
+	if (job->cancelled) {
+		g_object_unref (job);
 		return;
+	}
 
 	/* check if job finished previously */
-        if (job->finished)
+        if (job->finished) {
+		g_object_unref (job);
 		return;
+	}
 
 	/* show info for debugging */
 	xviewer_debug_message (DEBUG_JOBS,
@@ -566,8 +570,21 @@ xviewer_job_load_run (XviewerJob *job)
 			&job->error);
 
 	/* check if the current job was previously cancelled */
-	if (xviewer_job_is_cancelled (job))
+	if (xviewer_job_is_cancelled (job)) {
+		/* xviewer_image_load() above may have already finished
+		 * decoding the full image into memory before this
+		 * cancellation was noticed (e.g. small/cached files loading
+		 * faster than the user can browse past them). Since this
+		 * job's "finished" signal is never emitted, the image will
+		 * never be displayed or data-reffed, so its decoded pixel
+		 * data would otherwise leak forever. Force-release it. */
+		if (job_load->data & XVIEWER_IMAGE_DATA_IMAGE) {
+			xviewer_image_data_ref (job_load->image);
+			xviewer_image_data_unref (job_load->image);
+		}
+		g_object_unref (job);
 		return;
+	}
 
 	/* --- enter critical section --- */
 	g_mutex_lock (job->mutex);
@@ -857,8 +874,10 @@ xviewer_job_save_run (XviewerJob *job)
 	}
 
 	/* check if the current job was previously cancelled */
-	if (xviewer_job_is_cancelled (job))
+	if (xviewer_job_is_cancelled (job)) {
+		g_object_unref (job);
 		return;
+	}
 
 	save_job = XVIEWER_JOB_SAVE (job);
 
@@ -1233,6 +1252,7 @@ xviewer_job_thumbnail_run (XviewerJob *job)
 
 	if (!job_thumbnail->thumbnail) {
 		job->finished = TRUE;
+		g_object_unref (job);
 		return;
 	}
 

src/xviewer-list-store.c

@@ -417,6 +417,7 @@ file_monitor_changed_cb (GFileMonitor *monitor,
 					    -1);
 
 			xviewer_list_store_remove (store, &iter);
+			g_object_unref (image);
 		}
 		break;
 	case G_FILE_MONITOR_EVENT_CREATED:

src/xviewer-thumbnail.c

@@ -494,6 +494,7 @@ xviewer_thumbnail_load (XviewerImage *image, GError **error)
 	    (data->failed_thumb_exists && gnome_desktop_thumbnail_factory_has_valid_failed_thumbnail (factory, data->uri_str, data->mtime))) {
 		xviewer_debug_message (DEBUG_THUMBNAIL, "%s: bad permissions or valid failed thumbnail present",data->uri_str);
 		set_thumb_error (error, XVIEWER_THUMB_ERROR_GENERIC, "Thumbnail creation failed");
+		xviewer_thumb_data_free (data);
 		return NULL;
 	}
 

src/xviewer-window.c

@@ -931,6 +931,13 @@ xviewer_window_display_image (XviewerWindow *window, XviewerImage *image)
 	priv = window->priv;
 
 	if (image != NULL) {
+		g_signal_handlers_disconnect_by_func (image,
+						      image_thumb_changed_cb,
+						      window);
+		g_signal_handlers_disconnect_by_func (image,
+						      image_file_changed_cb,
+						      window);
+
 		g_signal_connect (image,
 				  "thumbnail_changed",
 				  G_CALLBACK (image_thumb_changed_cb),
@@ -1021,6 +1028,15 @@ xviewer_window_update_openwith_menu (XviewerWindow *window, XviewerImage *image)
 
         if (priv->actions_open_with != NULL) {
               gtk_ui_manager_remove_action_group (priv->ui_mgr, priv->actions_open_with);
+              /* gtk_ui_manager_insert_action_group() below takes its own
+               * reference; removing it only drops that one. The reference
+               * from gtk_action_group_new() (which this struct field has
+               * been implicitly holding) must be released here too,
+               * otherwise every action group -- and every GAppInfo/
+               * GKeyFile-backed action it holds for each installed
+               * "Open With" candidate app -- leaks on every single image
+               * display. */
+              g_object_unref (priv->actions_open_with);
               priv->actions_open_with = NULL;
         }
 
@@ -1150,8 +1166,25 @@ xviewer_window_clear_load_job (XviewerWindow *window)
 	XviewerWindowPrivate *priv = window->priv;
 
 	if (priv->load_job != NULL) {
-		if (!priv->load_job->finished)
+		if (!priv->load_job->finished) {
 			xviewer_job_cancel (priv->load_job);
+		} else {
+			/* The job already finished decoding the full image
+			 * before we got a chance to act on it: the "finished"
+			 * signal disconnected below never gets to run, so
+			 * xviewer_job_load_cb()/xviewer_window_display_image()
+			 * never see this image and never data-ref it. Without
+			 * this, the fully decoded pixel data would stay
+			 * resident forever. Force-release it. This is safe
+			 * even if this image happens to be on-screen already,
+			 * since data-ref/unref only frees when the count
+			 * would drop to zero. */
+			XviewerImage *load_image = XVIEWER_JOB_LOAD (priv->load_job)->image;
+			if (xviewer_image_has_data (load_image, XVIEWER_IMAGE_DATA_IMAGE)) {
+				xviewer_image_data_ref (load_image);
+				xviewer_image_data_unref (load_image);
+			}
+		}
 
 		g_signal_handlers_disconnect_by_func (priv->load_job,
 						      xviewer_job_progress_cb,