Call back after collecting all traces.

2008-03-24  Soren Sandmann <sandmann@daimi.au.dk>

        * collector.c (collect_traces): Call back after collecting all
        traces. 

        * TODO: update

        * process.c: Simpler code to find vmlinux 



svn path=/trunk/; revision=406

ChangeLog

@@ -1,3 +1,12 @@
+2008-03-24  Soren Sandmann <sandmann@daimi.au.dk>
+
+	* collector.c (collect_traces): Call back after collecting all
+	traces. 
+
+	* TODO: update
+
+	* process.c: Simpler code to find vmlinux 
+
 Sat Mar 29 11:14:38 2008  Søren Sandmann  <sandmann@redhat.com>
 
 	* unwind.[ch], testunwind.c: Beginning of a dwarf unwinder.

TODO

@@ -121,6 +121,22 @@ Before 1.2:
 		- do heuristic stackwalk in kernel
 		- do heuristic stackwalk in userland
 
+	- Send heuristic stack trace to user space, along with
+	  location on the stack. Then, in userspace analyze the
+	  machine code to determine the size of the stack frame at any
+	  point. The instructions that would need to be recognized are:
+
+	  	 subl <constant>, %esp
+		 addl <constant>, %esp
+		 leave
+		 jcc
+		 push
+		 pop
+
+	  GCC is unlikely to have different stack sizes at the entry
+	  to a basic block.
+
+	  We can often find a vmlinux in /lib/modules/<uname-r>/build.
 
 * "Expand all" is horrendously slow because update_screenshot gets called 
   for every "expanded" signal. In fact even normal expanding is really

collector.c

@@ -170,6 +170,8 @@ in_dead_period (Collector *collector)
 static void
 collect_traces (Collector *collector)
 {
+    gboolean first;
+    
     /* After a reset we ignore samples for a short period so that
      * a reset will actually cause 'samples' to become 0
      */
@@ -179,6 +181,8 @@ collect_traces (Collector *collector)
 	return;
     }
 
+    first = collector->n_samples == 0;
+    
     while (collector->current != collector->map_area->head)
     {
 	const SysprofStackTrace *trace;
@@ -211,10 +215,10 @@ collect_traces (Collector *collector)
 	    collector->current = 0;
 	
 	collector->n_samples++;
-	
-	if (collector->callback)
-	    collector->callback (collector->n_samples == 1, collector->data);
     }
+	
+    if (collector->callback)
+	collector->callback (first, collector->data);
 }
 
 static void

process.c

@@ -446,35 +446,28 @@ file_exists (const char *name)
 static gchar *
 look_for_vmlinux (void)
 {
+    static const char names[][48] = {
+	"/lib/modules/%s/build/vmlinux",
+	"/usr/lib/debug/lib/modules/%s/vmlinux",
+	"/lib/modules/%s/source/vmlinux",
+	"/boot/vmlinux-%s",
+    };
     struct utsname utsname;
-    char *result;
-    char **s;
-    char *names[4];
-
+    int i;
+    
     uname (&utsname);
 
-    names[0] = g_strdup_printf (
-	"/usr/lib/debug/lib/modules/%s/vmlinux", utsname.release);
-    names[1] = g_strdup_printf (
-	"/lib/modules/%s/source/vmlinux", utsname.release);
-    names[2] = g_strdup_printf (
-	"/boot/vmlinux-%s", utsname.release);
-    names[3] = NULL;
-
-    result = NULL;
-    for (s = names; *s; s++)
+    for (i = 0; i < G_N_ELEMENTS (names); ++i)
     {
-	if (file_exists (*s))
-	{
-	    result = g_strdup (*s);
-	    break;
-	}
+	char *filename = g_strdup_printf (names[i], utsname.release);
+
+	if (file_exists (filename))
+	    return filename;
+
+	g_free (filename);
     }
 
-    for (s = names; *s; s++)
-	g_free (*s);
-
-    return result;
+    return NULL;
 }
 
 static const gchar *