From dc51fea3b4e70c7da059b0e2252e50fde0ea33e1 Mon Sep 17 00:00:00 2001
From: Soeren Sandmann <sandmann@redhat.com>
Date: Fri, 24 Feb 2006 07:10:42 +0000
Subject: [PATCH] Clear screenshot window when start is toggled.

Fri Feb 24 02:09:33 2006  Soeren Sandmann  <sandmann@redhat.com>

        * sysprof.c (on_start_toggled): Clear screenshot window when start
        is toggled.

        * TODO: Add some notes about stack handling on the x86
---
 TODO      | 21 +++++++++++++++++++++
 sysprof.c | 38 +++++++++++++++++++++-----------------
 2 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/TODO b/TODO
index f768adbb..1646e36d 100644
--- a/TODO
+++ b/TODO
@@ -268,6 +268,27 @@ http://www.linuxbase.org/spec/booksets/LSB-Embedded/LSB-Embedded/ehframe.html
 - somehow get access to VSEnterprise profiler and see how it works.
   somehow get access to vtune and see how it works.
 
+* Some notes about timer interrupt handling in Linux
+
+On an SMP system APIC is used - the interesting file is arch/i386/kernel/apic.c
+
+On UP systems, the normal IRQ0 is used
+When the interrupt happens, 
+	entry.S
+		calls do_IRQ, which sets up the special interrupt stack, 
+		and calls __do_IRQ, which is in /kernel/irq/handle.c.
+		This calls the corresponding irqaction, which has previously
+		been setup by arch/i386/mach-default/setup.c to point to
+		timer_interrupt, which is in arch/i386/kernel/time.c.
+		This calls do_timer_interrupt_hooks() which is defined in
+		/include/asm-i386/mach-default/do_timer.h. This function
+		then calls profile_tick().
+
+	Note when the CPU switches from user mode to kernel mode, it 
+	pushes SS/ESP on top of the kernel stack, but when it switches
+	from kernel mode to kernel mode, it does _not_ push SS/ESP.
+	It does in both cases push EIP though.
+
 Later:
 
 - See if it is possible to group the X server activity under the process that
diff --git a/sysprof.c b/sysprof.c
index 495c7902..2d1bfc91 100644
--- a/sysprof.c
+++ b/sysprof.c
@@ -105,6 +105,8 @@ struct Application
 					    */
 };
 
+static void update_screenshot_window (Application *app);
+
 static gboolean
 show_samples_timeout (gpointer data)
 {
@@ -361,7 +363,7 @@ static void
 on_start_toggled (GtkWidget *widget, gpointer data)
 {
     Application *app = data;
-    
+
     if (!gtk_toggle_tool_button_get_active (
 	    GTK_TOGGLE_TOOL_BUTTON (app->start_button)))
     {
@@ -385,7 +387,8 @@ on_start_toggled (GtkWidget *widget, gpointer data)
 	       "\n"
 	       "as root.");
     }
-    
+
+    update_screenshot_window (app);
     update_sensitivity (app);
 }
 
@@ -1085,6 +1088,17 @@ typedef struct
     GString *text;
 } AddTextInfo;
 
+static void
+set_monospace (GtkWidget *widget)
+{
+    PangoFontDescription *desc =
+	pango_font_description_from_string ("monospace");
+    
+    gtk_widget_modify_font (widget, desc);
+    
+    pango_font_description_free (desc);
+}
+
 static void
 add_text (GtkTreeView *view,
 	  GtkTreePath *path,
@@ -1108,21 +1122,13 @@ add_text (GtkTreeView *view,
     g_string_append_printf (info->text, "%-*s %6.2f %6.2f\n", info->max_width - indent, name, self, cumulative);
 }
 
-static void
-set_monospace (GtkWidget *widget)
-{
-    PangoFontDescription *desc =
-	pango_font_description_from_string ("monospace");
-    
-    gtk_widget_modify_font (widget, desc);
-    
-    pango_font_description_free (desc);
-}
-
 static void
 update_screenshot_window (Application *app)
 {
-    /* FIXME: clear the text buffer here */
+    GtkTextBuffer *text_buffer =
+	gtk_text_view_get_buffer (GTK_TEXT_VIEW (app->screenshot_textview));
+
+    gtk_text_buffer_set_text (text_buffer, "", -1);
     
     if (app->descendants)
     {
@@ -1139,9 +1145,7 @@ update_screenshot_window (Application *app)
 				   add_text,
 				   &info);
 
-	gtk_text_buffer_set_text (
-	    gtk_text_view_get_buffer (GTK_TEXT_VIEW (app->screenshot_textview)),
-	    info.text->str, -1);
+	gtk_text_buffer_set_text (text_buffer, info.text->str, -1);
 
 	set_monospace (app->screenshot_textview);