wip

gdk/backtrace-helper.h

@@ -0,0 +1,81 @@
+/* backtrace-helper.h
+ *
+ * Copyright 2020-2023 Christian Hergert <chergert@redhat.com>
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of the
+ * License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#pragma once
+
+#include <sysprof-capture.h>
+
+#ifdef HAVE_EXECINFO_H
+# include <execinfo.h>
+#endif
+#ifdef ENABLE_LIBUNWIND
+# define UNW_LOCAL_ONLY
+# include <libunwind.h>
+#endif
+
+static void
+backtrace_init (void)
+{
+#ifdef ENABLE_LIBUNWIND
+  unw_set_caching_policy (unw_local_addr_space, UNW_CACHE_PER_THREAD);
+# ifdef HAVE_UNW_SET_CACHE_SIZE
+  unw_set_cache_size (unw_local_addr_space, 1024, 0);
+#endif
+#endif
+}
+
+static int
+backtrace_func (SysprofCaptureAddress  *addrs,
+                guint                   n_addrs,
+                G_GNUC_UNUSED gpointer  user_data)
+{
+#if defined(ENABLE_LIBUNWIND)
+# if GLIB_SIZEOF_VOID_P == 8
+  /* We know that collector will overwrite fields *AFTER* it
+   * has called the backtrace function allowing us to cheat
+   * and subtract an offset from addrs to avoid having to
+   * copy frame pointers around.
+   */
+  return unw_backtrace ((void **)addrs - 2, n_addrs) - 2;
+# else
+  static const int skip = 2;
+  void **stack = alloca (n_addrs * sizeof (gpointer));
+  int n = unw_backtrace (stack, n_addrs);
+  for (guint i = skip; i < n; i++)
+    addrs[i-skip] = GPOINTER_TO_SIZE (stack[i]);
+  return MAX (0, n - skip);
+# endif
+#elif defined(HAVE_EXECINFO_H)
+# if GLIB_SIZEOF_VOID_P == 8
+  /* See note on unw_backtrace() */
+  return backtrace ((void **)addrs - 2, n_addrs) - 2;
+# else /* GLIB_SIZEOF_VOID_P != 8 */
+  static const int skip = 2;
+  void **stack = alloca (n_addrs * sizeof (gpointer));
+  int n = backtrace (stack, n_addrs);
+  for (guint i = skip; i < n; i++)
+    addrs[i-skip] = GPOINTER_TO_SIZE (stack[i]);
+  return MAX (0, n - skip);
+# endif /* GLIB_SIZEOF_VOID_P */
+#else
+  return 0;
+#endif
+}
+

gdk/gdkprofiler.c

@@ -32,6 +32,9 @@
 #include "gdkversionmacros.h"
 #include "gdkframeclockprivate.h"
 
+#ifdef HAVE_SYSPROF
+# include "backtrace-helper.h"
+#endif
 
 gboolean
 gdk_profiler_is_running (void)
@@ -160,3 +163,19 @@ void
   sysprof_collector_set_counters (&id, &value, 1);
 #endif
 }
+
+void
+(gdk_profiler_add_stacktrace) (void)
+{
+#ifdef HAVE_SYSPROF
+  static gsize did_init;
+
+  if (!did_init)
+    {
+      did_init = TRUE;
+      backtrace_init ();
+    }
+
+  sysprof_collector_sample (backtrace_func, NULL);
+#endif
+}

gdk/gdkprofilerprivate.h

@@ -63,6 +63,8 @@ void   gdk_profiler_end_markf (gint64       begin_time,
                                const gchar *message_format,
                                ...) G_GNUC_PRINTF (3, 4);
 
+void    gdk_profiler_add_stacktrace (void);
+
 guint   gdk_profiler_define_counter     (const char *name,
                                          const char *description);
 guint   gdk_profiler_define_int_counter (const char *name,
@@ -86,6 +88,8 @@ void    gdk_profiler_set_int_counter    (guint  id,
 /* no varargs macro support; the call will have to be optimised out by the compiler */
 #endif
 
+#define gdk_profiler_add_stacktrace() G_STMT_START {} G_STMT_END
+
 #define gdk_profiler_define_counter(n, d) 0
 #define gdk_profiler_define_int_counter(n, d) 0
 #define gdk_profiler_set_counter(i, v) G_STMT_START {} G_STMT_END

gtk/gtkrange.c

@@ -27,6 +27,8 @@
 
 #include "gtkrangeprivate.h"
 
+#include "gdkprofilerprivate.h"
+
 #include "gtkaccessible.h"
 #include "gtkaccessiblerange.h"
 #include "gtkadjustmentprivate.h"
@@ -2348,6 +2350,8 @@ gtk_range_adjustment_changed (GtkAdjustment *adjustment,
   double upper = gtk_adjustment_get_upper (priv->adjustment);
   double lower = gtk_adjustment_get_lower (priv->adjustment);
 
+  gdk_profiler_add_stacktrace ();
+
   gtk_widget_set_visible (priv->slider_widget, upper != lower || !GTK_IS_SCALE (range));
 
   gtk_widget_queue_allocate (priv->trough_widget);

meson.build

@@ -156,6 +156,7 @@ check_headers = [
   'crt/externs.h',
   'dev/evdev/input.h',
   'dlfcn.h',
+  'execinfo.h',
   'ftw.h',
   'inttypes.h',
   'linux/input.h',