diff --git a/boilerplate/Makefile.win32.features b/boilerplate/Makefile.win32.features
index 0cf7095b7..cb33fe539 100644
--- a/boilerplate/Makefile.win32.features
+++ b/boilerplate/Makefile.win32.features
@@ -408,6 +408,16 @@ enabled_cairo_boilerplate_private += $(cairo_boilerplate_recording_private)
 enabled_cairo_boilerplate_cxx_sources += $(cairo_boilerplate_recording_cxx_sources)
 enabled_cairo_boilerplate_sources += $(cairo_boilerplate_recording_sources)
 
+supported_cairo_boilerplate_headers += $(cairo_boilerplate_observer_headers)
+all_cairo_boilerplate_headers += $(cairo_boilerplate_observer_headers)
+all_cairo_boilerplate_private += $(cairo_boilerplate_observer_private)
+all_cairo_boilerplate_cxx_sources += $(cairo_boilerplate_observer_cxx_sources)
+all_cairo_boilerplate_sources += $(cairo_boilerplate_observer_sources)
+enabled_cairo_boilerplate_headers += $(cairo_boilerplate_observer_headers)
+enabled_cairo_boilerplate_private += $(cairo_boilerplate_observer_private)
+enabled_cairo_boilerplate_cxx_sources += $(cairo_boilerplate_observer_cxx_sources)
+enabled_cairo_boilerplate_sources += $(cairo_boilerplate_observer_sources)
+
 unsupported_cairo_boilerplate_headers += $(cairo_boilerplate_tee_headers)
 all_cairo_boilerplate_headers += $(cairo_boilerplate_tee_headers)
 all_cairo_boilerplate_private += $(cairo_boilerplate_tee_private)
diff --git a/build/Makefile.win32.features-h b/build/Makefile.win32.features-h
index e35cc6c5e..e49ad6e6d 100644
--- a/build/Makefile.win32.features-h
+++ b/build/Makefile.win32.features-h
@@ -100,6 +100,7 @@ ifeq ($(CAIRO_HAS_TEST_SURFACES),1)
 endif
 	@echo "#define CAIRO_HAS_IMAGE_SURFACE 1" >> $(top_srcdir)/src/cairo-features.h
 	@echo "#define CAIRO_HAS_RECORDING_SURFACE 1" >> $(top_srcdir)/src/cairo-features.h
+	@echo "#define CAIRO_HAS_OBSERVER_SURFACE 1" >> $(top_srcdir)/src/cairo-features.h
 ifeq ($(CAIRO_HAS_TEE_SURFACE),1)
 	@echo "#define CAIRO_HAS_TEE_SURFACE 1" >> $(top_srcdir)/src/cairo-features.h
 endif
diff --git a/build/configure.ac.features b/build/configure.ac.features
index 4cccd9cf3..4f774e308 100644
--- a/build/configure.ac.features
+++ b/build/configure.ac.features
@@ -365,6 +365,7 @@ AC_DEFUN([CAIRO_REPORT],
 	echo "The following surface backends:"
 	echo "  Image:         yes (always builtin)"
 	echo "  Recording:     yes (always builtin)"
+	echo "  Observer:      yes (always builtin)"
 	echo "  Tee:           $use_tee"
 	echo "  XML:           $use_xml"
 	echo "  Skia:          $use_skia"
diff --git a/configure.ac b/configure.ac
index f659729d1..50efecc9c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -621,6 +621,7 @@ CAIRO_ENABLE_SURFACE_BACKEND(image, image, always, [
 dnl ===========================================================================
 
 CAIRO_ENABLE_SURFACE_BACKEND(recording, recording, always)
+CAIRO_ENABLE_SURFACE_BACKEND(observer, observer, always)
 CAIRO_ENABLE_SURFACE_BACKEND(tee, tee, no)
 CAIRO_ENABLE_SURFACE_BACKEND(xml, xml, no, [
     use_xml=$have_libz
diff --git a/perf/.gitignore b/perf/.gitignore
index bc8b9bf10..3ac12bbc2 100644
--- a/perf/.gitignore
+++ b/perf/.gitignore
@@ -1,5 +1,6 @@
 TAGS
 tags
+cairo-analyse-trace
 cairo-perf
 cairo-perf-micro
 cairo-perf-print
diff --git a/perf/Makefile.am b/perf/Makefile.am
index d41891f6c..3ac60da58 100644
--- a/perf/Makefile.am
+++ b/perf/Makefile.am
@@ -14,15 +14,22 @@ AM_LDFLAGS = $(CAIRO_LDFLAGS)
 
 SUBDIRS = micro
 
-noinst_PROGRAMS = cairo-perf-trace cairo-perf-micro
+noinst_PROGRAMS = \
+	cairo-analyse-trace \
+	cairo-perf-trace \
+	cairo-perf-micro \
+	$(NULL)
 
-EXTRA_PROGRAMS += cairo-perf-micro \
-		  cairo-perf-trace \
-		  cairo-perf-diff-files \
-		  cairo-perf-print \
-		  cairo-perf-chart \
-		  cairo-perf-compare-backends \
-		  cairo-perf-graph-files
+EXTRA_PROGRAMS += \
+	cairo-analyse-trace \
+	cairo-perf-micro \
+	cairo-perf-trace \
+	cairo-perf-diff-files \
+	cairo-perf-print \
+	cairo-perf-chart \
+	cairo-perf-compare-backends \
+	cairo-perf-graph-files \
+	$(NULL)
 EXTRA_DIST += cairo-perf-diff COPYING
 EXTRA_LTLIBRARIES += libcairoperf.la
 
@@ -43,6 +50,16 @@ libcairoperf_la_SOURCES = \
 	$(libcairoperf_headers)
 libcairoperf_la_LIBADD = $(CAIROPERF_LIBS)
 
+cairo_analyse_trace_SOURCES = \
+	$(cairo_analyse_trace_sources)	\
+	$(cairo_analyse_trace_external_sources)
+cairo_analyse_trace_LDADD =		\
+	$(top_builddir)/util/cairo-script/libcairo-script-interpreter.la \
+	$(LDADD)
+cairo_analyse_trace_DEPENDENCIES = \
+	$(top_builddir)/util/cairo-script/libcairo-script-interpreter.la \
+	$(LDADD)
+
 cairo_perf_trace_SOURCES = \
 	$(cairo_perf_trace_sources)	\
 	$(cairo_perf_trace_external_sources)
diff --git a/perf/Makefile.sources b/perf/Makefile.sources
index 9867ea526..0c15ae9c7 100644
--- a/perf/Makefile.sources
+++ b/perf/Makefile.sources
@@ -11,6 +11,9 @@ libcairoperf_headers = \
 	cairo-stats.h  \
 	$(NULL)
 
+cairo_analyse_trace_sources = cairo-analyse-trace.c
+cairo_analyse_trace_external_sources = ../src/cairo-error.c
+
 cairo_perf_trace_sources = cairo-perf-trace.c
 cairo_perf_trace_external_sources = \
 	../src/cairo-error.c \
diff --git a/perf/cairo-analyse-trace.c b/perf/cairo-analyse-trace.c
new file mode 100644
index 000000000..206ff8612
--- /dev/null
+++ b/perf/cairo-analyse-trace.c
@@ -0,0 +1,646 @@
+/* -*- Mode: c; c-basic-offset: 4; indent-tabs-mode: t; tab-width: 8; -*- */
+/*
+ * Copyright © 2006 Mozilla Corporation
+ * Copyright © 2006 Red Hat, Inc.
+ * Copyright © 2009 Chris Wilson
+ * Copyright © 2011 Intel Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of
+ * the authors not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. The authors make no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE AUTHORS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL,
+ * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+ * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Authors: Vladimir Vukicevic <vladimir@pobox.com>
+ *	    Carl Worth <cworth@cworth.org>
+ *	    Chris Wilson <chris@chris-wilson.co.uk>
+ */
+
+#define _GNU_SOURCE 1	/* for sched_getaffinity() and getline() */
+
+#include "../cairo-version.h" /* for the real version */
+
+#include "cairo-perf.h"
+#include "cairo-stats.h"
+
+#include "cairo-boilerplate-getopt.h"
+#include <cairo-script-interpreter.h>
+
+/* rudely reuse bits of the library... */
+#include "../src/cairo-error-private.h"
+
+/* For basename */
+#ifdef HAVE_LIBGEN_H
+#include <libgen.h>
+#endif
+#include <ctype.h> /* isspace() */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#ifdef _MSC_VER
+#include "dirent-win32.h"
+
+typedef SSIZE_T ssize_t;
+
+static char *
+basename_no_ext (char *path)
+{
+    static char name[_MAX_FNAME + 1];
+
+    _splitpath (path, NULL, NULL, name, NULL);
+
+    name[_MAX_FNAME] = '\0';
+
+    return name;
+}
+
+
+#else
+#include <dirent.h>
+
+static char *
+basename_no_ext (char *path)
+{
+    char *dot, *name;
+
+    name = basename (path);
+
+    dot = strchr (name, '.');
+    if (dot)
+	*dot = '\0';
+
+    return name;
+}
+
+#endif
+
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include <signal.h>
+
+#if HAVE_FCFINI
+#include <fontconfig/fontconfig.h>
+#endif
+
+struct trace {
+    const cairo_boilerplate_target_t *target;
+    void            *closure;
+    cairo_surface_t *surface;
+};
+
+cairo_bool_t
+cairo_perf_can_run (cairo_perf_t *perf,
+		    const char	 *name,
+		    cairo_bool_t *is_explicit)
+{
+    unsigned int i;
+    char *copy, *dot;
+    cairo_bool_t ret;
+
+    if (is_explicit)
+	*is_explicit = FALSE;
+
+    if (perf->exact_names) {
+	if (is_explicit)
+	    *is_explicit = TRUE;
+	return TRUE;
+    }
+
+    if (perf->num_names == 0 && perf->num_exclude_names == 0)
+	return TRUE;
+
+    copy = xstrdup (name);
+    dot = strchr (copy, '.');
+    if (dot != NULL)
+	*dot = '\0';
+
+    if (perf->num_names) {
+	ret = TRUE;
+	for (i = 0; i < perf->num_names; i++)
+	    if (strstr (copy, perf->names[i])) {
+		if (is_explicit)
+		    *is_explicit = strcmp (copy, perf->names[i]) == 0;
+		goto check_exclude;
+	    }
+
+	ret = FALSE;
+	goto done;
+    }
+
+check_exclude:
+    if (perf->num_exclude_names) {
+	ret = FALSE;
+	for (i = 0; i < perf->num_exclude_names; i++)
+	    if (strstr (copy, perf->exclude_names[i])) {
+		if (is_explicit)
+		    *is_explicit = strcmp (copy, perf->exclude_names[i]) == 0;
+		goto done;
+	    }
+
+	ret = TRUE;
+	goto done;
+    }
+
+done:
+    free (copy);
+
+    return ret;
+}
+
+static cairo_surface_t *
+surface_create (void		 *closure,
+		cairo_content_t  content,
+		double		  width,
+		double		  height,
+		long		  uid)
+{
+    struct trace *args = closure;
+    return cairo_surface_create_similar (args->surface, content, width, height);
+}
+
+static int user_interrupt;
+
+static void
+interrupt (int sig)
+{
+    if (user_interrupt) {
+	signal (sig, SIG_DFL);
+	raise (sig);
+    }
+
+    user_interrupt = 1;
+}
+
+static void
+describe (cairo_perf_t *perf,
+          void *closure)
+{
+    char *description = NULL;
+
+    if (perf->has_described_backend)
+	    return;
+    perf->has_described_backend = TRUE;
+
+    if (perf->target->describe)
+        description = perf->target->describe (closure);
+
+    if (description == NULL)
+        return;
+
+    free (description);
+}
+
+static void
+execute (cairo_perf_t	 *perf,
+	 struct trace	 *args,
+	 const char	 *trace)
+{
+    char *trace_cpy, *name;
+    const cairo_script_interpreter_hooks_t hooks = {
+	.closure = args,
+	.surface_create = surface_create,
+    };
+
+    trace_cpy = xstrdup (trace);
+    name = basename_no_ext (trace_cpy);
+
+    if (perf->list_only) {
+	printf ("%s\n", name);
+	free (trace_cpy);
+	return;
+    }
+
+    describe (perf, args->closure);
+
+    {
+	cairo_script_interpreter_t *csi;
+	cairo_status_t status;
+	unsigned int line_no;
+
+	csi = cairo_script_interpreter_create ();
+	cairo_script_interpreter_install_hooks (csi, &hooks);
+
+	cairo_script_interpreter_run (csi, trace);
+
+	cairo_script_interpreter_finish (csi);
+
+	line_no = cairo_script_interpreter_get_line_number (csi);
+	status = cairo_script_interpreter_destroy (csi);
+	if (status) {
+	    /* XXXX cairo_status_to_string is just wrong! */
+	    fprintf (stderr, "Error during replay, line %d: %s\n",
+		     line_no, cairo_status_to_string (status));
+	}
+    }
+    user_interrupt = 0;
+
+    free (trace_cpy);
+}
+
+static void
+usage (const char *argv0)
+{
+    fprintf (stderr,
+"Usage: %s [-l] [-r] [-v] [-i iterations] [test-names ... | traces ...]\n"
+"       %s -l\n"
+"\n"
+"Run the cairo performance test suite over the given tests (all by default)\n"
+"The command-line arguments are interpreted as follows:\n"
+"\n"
+"  -v	verbose\n"
+"  -x   exclude; specify a file to read a list of traces to exclude\n"
+"  -l	list only; just list selected test case names without executing\n"
+"\n"
+"If test names are given they are used as sub-string matches so a command\n"
+"such as \"cairo-perf-trace firefox\" can be used to run all firefox traces.\n"
+"Alternatively, you can specify a list of filenames to execute.\n",
+	     argv0, argv0);
+}
+
+#ifndef __USE_GNU
+#define POORMANS_GETLINE_BUFFER_SIZE (65536)
+static ssize_t
+getline (char	**lineptr,
+	 size_t  *n,
+	 FILE	 *stream)
+{
+    if (!*lineptr)
+    {
+	*n = POORMANS_GETLINE_BUFFER_SIZE;
+	*lineptr = (char *) malloc (*n);
+    }
+
+    if (!fgets (*lineptr, *n, stream))
+	return -1;
+
+    if (!feof (stream) && !strchr (*lineptr, '\n'))
+    {
+	fprintf (stderr, "The poor man's implementation of getline in "
+			  __FILE__ " needs a bigger buffer. Perhaps it's "
+			 "time for a complete implementation of getline.\n");
+	exit (0);
+    }
+
+    return strlen (*lineptr);
+}
+#undef POORMANS_GETLINE_BUFFER_SIZE
+
+static char *
+strndup (const char *s,
+	 size_t      n)
+{
+    size_t len;
+    char *sdup;
+
+    if (!s)
+	return NULL;
+
+    len = strlen (s);
+    len = (n < len ? n : len);
+    sdup = (char *) malloc (len + 1);
+    if (sdup)
+    {
+	memcpy (sdup, s, len);
+	sdup[len] = '\0';
+    }
+
+    return sdup;
+}
+#endif /* ifndef __USE_GNU */
+
+static cairo_bool_t
+read_excludes (cairo_perf_t *perf,
+	       const char   *filename)
+{
+    FILE *file;
+    char *line = NULL;
+    size_t line_size = 0;
+    char *s, *t;
+
+    file = fopen (filename, "r");
+    if (file == NULL)
+	return FALSE;
+
+    while (getline (&line, &line_size, file) != -1) {
+	/* terminate the line at a comment marker '#' */
+	s = strchr (line, '#');
+	if (s)
+	    *s = '\0';
+
+	/* whitespace delimits */
+	s = line;
+	while (*s != '\0' && isspace (*s))
+	    s++;
+
+	t = s;
+	while (*t != '\0' && ! isspace (*t))
+	    t++;
+
+	if (s != t) {
+	    int i = perf->num_exclude_names;
+	    perf->exclude_names = xrealloc (perf->exclude_names,
+					    sizeof (char *) * (i+1));
+	    perf->exclude_names[i] = strndup (s, t-s);
+	    perf->num_exclude_names++;
+	}
+    }
+    free (line);
+
+    fclose (file);
+
+    return TRUE;
+}
+
+static void
+parse_options (cairo_perf_t *perf,
+	       int	     argc,
+	       char	    *argv[])
+{
+    char *end;
+    int c;
+
+    perf->list_only = FALSE;
+    perf->names = NULL;
+    perf->num_names = 0;
+    perf->exclude_names = NULL;
+    perf->num_exclude_names = 0;
+
+    while (1) {
+	c = _cairo_getopt (argc, argv, "i:x:lrvc");
+	if (c == -1)
+	    break;
+
+	switch (c) {
+	case 'i':
+	    perf->exact_iterations = TRUE;
+	    perf->iterations = strtoul (optarg, &end, 10);
+	    if (*end != '\0') {
+		fprintf (stderr, "Invalid argument for -i (not an integer): %s\n",
+			 optarg);
+		exit (1);
+	    }
+	    break;
+	case 'l':
+	    perf->list_only = TRUE;
+	    break;
+	case 'x':
+	    if (! read_excludes (perf, optarg)) {
+		fprintf (stderr, "Invalid argument for -x (not readable file): %s\n",
+			 optarg);
+		exit (1);
+	    }
+	    break;
+	default:
+	    fprintf (stderr, "Internal error: unhandled option: %c\n", c);
+	    /* fall-through */
+	case '?':
+	    usage (argv[0]);
+	    exit (1);
+	}
+    }
+
+    if (optind < argc) {
+	perf->names = &argv[optind];
+	perf->num_names = argc - optind;
+    }
+}
+
+static void
+cairo_perf_fini (cairo_perf_t *perf)
+{
+    cairo_boilerplate_free_targets (perf->targets);
+    cairo_boilerplate_fini ();
+
+    free (perf->times);
+    cairo_debug_reset_static_data ();
+#if HAVE_FCFINI
+    FcFini ();
+#endif
+}
+
+static cairo_bool_t
+have_trace_filenames (cairo_perf_t *perf)
+{
+    unsigned int i;
+
+    if (perf->num_names == 0)
+	return FALSE;
+
+#if HAVE_UNISTD_H
+    for (i = 0; i < perf->num_names; i++)
+	if (access (perf->names[i], R_OK) == 0)
+	    return TRUE;
+#endif
+
+    return FALSE;
+}
+
+static cairo_status_t
+print (void *closure, const unsigned char *data, unsigned int length)
+{
+    fwrite (data, length, 1, closure);
+    return CAIRO_STATUS_SUCCESS;
+}
+
+static void
+cairo_perf_trace (cairo_perf_t			   *perf,
+		  const cairo_boilerplate_target_t *target,
+		  const char			   *trace)
+{
+    struct trace args;
+    cairo_surface_t *real;
+
+    args.target = target;
+    real = target->create_surface (NULL,
+				   CAIRO_CONTENT_COLOR_ALPHA,
+				   1, 1,
+				   1, 1,
+				   CAIRO_BOILERPLATE_MODE_PERF,
+				   0,
+				   &args.closure);
+    args.surface = cairo_surface_create_observer (real);
+    cairo_surface_destroy (real);
+    if (cairo_surface_status (args.surface)) {
+	fprintf (stderr,
+		 "Error: Failed to create target surface: %s\n",
+		 target->name);
+	return;
+    }
+
+    printf ("Observing '%s'...", trace);
+    fflush (stdout);
+
+    execute (perf, &args, trace);
+
+    printf ("\n");
+    cairo_device_observer_print (cairo_surface_get_device (args.surface),
+				 print, stdout);
+    fflush (stdout);
+
+    cairo_surface_destroy (args.surface);
+
+    if (target->cleanup)
+	target->cleanup (args.closure);
+}
+
+static void
+warn_no_traces (const char *message,
+		const char *trace_dir)
+{
+    fprintf (stderr,
+"Error: %s '%s'.\n"
+"Have you cloned the cairo-traces repository and uncompressed the traces?\n"
+"  git clone git://anongit.freedesktop.org/cairo-traces\n"
+"  cd cairo-traces && make\n"
+"Or set the env.var CAIRO_TRACE_DIR to point to your traces?\n",
+	    message, trace_dir);
+}
+
+static int
+cairo_perf_trace_dir (cairo_perf_t		       *perf,
+		      const cairo_boilerplate_target_t *target,
+		      const char		       *dirname)
+{
+    DIR *dir;
+    struct dirent *de;
+    int num_traces = 0;
+    cairo_bool_t force;
+    cairo_bool_t is_explicit;
+
+    dir = opendir (dirname);
+    if (dir == NULL)
+	return 0;
+
+    force = FALSE;
+    if (cairo_perf_can_run (perf, dirname, &is_explicit))
+	force = is_explicit;
+
+    while ((de = readdir (dir)) != NULL) {
+	char *trace;
+	struct stat st;
+
+	if (de->d_name[0] == '.')
+	    continue;
+
+	xasprintf (&trace, "%s/%s", dirname, de->d_name);
+	if (stat (trace, &st) != 0)
+	    goto next;
+
+	if (S_ISDIR(st.st_mode)) {
+	    num_traces += cairo_perf_trace_dir (perf, target, trace);
+	} else {
+	    const char *dot;
+
+	    dot = strrchr (de->d_name, '.');
+	    if (dot == NULL)
+		goto next;
+	    if (strcmp (dot, ".trace"))
+		goto next;
+
+	    num_traces++;
+	    if (!force && ! cairo_perf_can_run (perf, de->d_name, NULL))
+		goto next;
+
+	    cairo_perf_trace (perf, target, trace);
+	}
+next:
+	free (trace);
+
+    }
+    closedir (dir);
+
+    return num_traces;
+}
+
+int
+main (int   argc,
+      char *argv[])
+{
+    cairo_perf_t perf;
+    const char *trace_dir = "cairo-traces:/usr/src/cairo-traces:/usr/share/cairo-traces";
+    unsigned int n;
+    int i;
+
+    parse_options (&perf, argc, argv);
+
+    signal (SIGINT, interrupt);
+
+    if (getenv ("CAIRO_TRACE_DIR") != NULL)
+	trace_dir = getenv ("CAIRO_TRACE_DIR");
+
+    perf.targets = cairo_boilerplate_get_targets (&perf.num_targets, NULL);
+    perf.times = xmalloc (perf.iterations * sizeof (cairo_perf_ticks_t));
+
+    /* do we have a list of filenames? */
+    perf.exact_names = have_trace_filenames (&perf);
+
+    for (i = 0; i < perf.num_targets; i++) {
+	const cairo_boilerplate_target_t *target = perf.targets[i];
+
+	if (! perf.list_only && ! target->is_measurable)
+	    continue;
+
+	perf.target = target;
+	perf.has_described_backend = FALSE;
+
+	if (perf.exact_names) {
+	    for (n = 0; n < perf.num_names; n++) {
+		struct stat st;
+
+		if (stat (perf.names[n], &st) == 0) {
+		    if (S_ISDIR (st.st_mode)) {
+			cairo_perf_trace_dir (&perf, target, perf.names[n]);
+		    } else
+			cairo_perf_trace (&perf, target, perf.names[n]);
+		}
+	    }
+	} else {
+	    int num_traces = 0;
+	    const char *dir;
+
+	    dir = trace_dir;
+	    do {
+		char buf[1024];
+		const char *end = strchr (dir, ':');
+		if (end != NULL) {
+		    memcpy (buf, dir, end-dir);
+		    buf[end-dir] = '\0';
+		    end++;
+
+		    dir = buf;
+		}
+
+		num_traces += cairo_perf_trace_dir (&perf, target, dir);
+		dir = end;
+	    } while (dir != NULL);
+
+	    if (num_traces == 0) {
+		warn_no_traces ("Found no traces in", trace_dir);
+		return 1;
+	    }
+	}
+
+	if (perf.list_only)
+	    break;
+    }
+
+    cairo_perf_fini (&perf);
+
+    return 0;
+}
diff --git a/src/Makefile.sources b/src/Makefile.sources
index c007d18f8..a47a01087 100644
--- a/src/Makefile.sources
+++ b/src/Makefile.sources
@@ -100,6 +100,7 @@ cairo_private = \
 	cairo-surface-fallback-private.h \
 	cairo-surface-private.h \
 	cairo-surface-clipper-private.h \
+	cairo-surface-observer-private.h \
 	cairo-surface-offset-private.h \
 	cairo-surface-subsurface-private.h \
 	cairo-surface-snapshot-private.h \
@@ -181,6 +182,7 @@ cairo_sources = \
 	cairo-surface.c \
 	cairo-surface-fallback.c \
 	cairo-surface-clipper.c \
+	cairo-surface-observer.c \
 	cairo-surface-offset.c \
 	cairo-surface-snapshot.c \
 	cairo-surface-subsurface.c \
diff --git a/src/Makefile.win32.features b/src/Makefile.win32.features
index 640df730b..8cfd6e76a 100644
--- a/src/Makefile.win32.features
+++ b/src/Makefile.win32.features
@@ -530,6 +530,16 @@ enabled_cairo_private += $(cairo_recording_private)
 enabled_cairo_cxx_sources += $(cairo_recording_cxx_sources)
 enabled_cairo_sources += $(cairo_recording_sources)
 
+supported_cairo_headers += $(cairo_observer_headers)
+all_cairo_headers += $(cairo_observer_headers)
+all_cairo_private += $(cairo_observer_private)
+all_cairo_cxx_sources += $(cairo_observer_cxx_sources)
+all_cairo_sources += $(cairo_observer_sources)
+enabled_cairo_headers += $(cairo_observer_headers)
+enabled_cairo_private += $(cairo_observer_private)
+enabled_cairo_cxx_sources += $(cairo_observer_cxx_sources)
+enabled_cairo_sources += $(cairo_observer_sources)
+
 unsupported_cairo_headers += $(cairo_tee_headers)
 all_cairo_headers += $(cairo_tee_headers)
 all_cairo_private += $(cairo_tee_private)
diff --git a/src/cairo-surface-observer-private.h b/src/cairo-surface-observer-private.h
new file mode 100644
index 000000000..522be6a80
--- /dev/null
+++ b/src/cairo-surface-observer-private.h
@@ -0,0 +1,168 @@
+/* cairo - a vector graphics library with display and print output
+ *
+ * Copyright © 2011 Intel Corporation
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it either under the terms of the GNU Lesser General Public
+ * License version 2.1 as published by the Free Software Foundation
+ * (the "LGPL") or, at your option, under the terms of the Mozilla
+ * Public License Version 1.1 (the "MPL"). If you do not alter this
+ * notice, a recipient may use your version of this file under either
+ * the MPL or the LGPL.
+ *
+ * You should have received a copy of the LGPL along with this library
+ * in the file COPYING-LGPL-2.1; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
+ * You should have received a copy of the MPL along with this library
+ * in the file COPYING-MPL-1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
+ * OF ANY KIND, either express or implied. See the LGPL or the MPL for
+ * the specific language governing rights and limitations.
+ *
+ * The Original Code is the cairo graphics library.
+ *
+ * The Initial Developer of the Original Code is Intel Corporation.
+ *
+ * Contributor(s):
+ *      Chris Wilson <chris@chris-wilson.co.uk>
+ */
+
+#ifndef CAIRO_SURFACE_SNAPSHOT_PRIVATE_H
+#define CAIRO_SURFACE_SNAPSHOT_PRIVATE_H
+
+#include "cairo-device-private.h"
+#include "cairo-surface-private.h"
+
+struct stat {
+    double min, max, sum, sum_sq;
+    unsigned count;
+};
+
+#define NUM_OPERATORS (CAIRO_OPERATOR_HSL_LUMINOSITY+1)
+#define NUM_CAPS (CAIRO_LINE_CAP_SQUARE+1)
+#define NUM_JOINS (CAIRO_LINE_JOIN_BEVEL+1)
+#define NUM_ANTIALIAS (CAIRO_ANTIALIAS_SUBPIXEL+1)
+#define NUM_FILL_RULE (CAIRO_FILL_RULE_EVEN_ODD+1)
+
+struct extents {
+    struct stat area;
+    unsigned int bounded, unbounded;
+};
+
+struct pattern {
+    unsigned int type[7]; /* native/record/other surface/gradients */
+};
+
+struct path {
+    unsigned int type[5]; /* empty/pixel/rectilinear/straight/curved */
+};
+
+struct clip {
+    unsigned int type[4]; /* none, region, boxes, general */
+};
+
+typedef struct _cairo_observation cairo_observation_t;
+typedef struct _cairo_device_observer cairo_device_observer_t;
+
+struct _cairo_observation {
+    int num_surfaces;
+    int num_contexts;
+    int num_sources_acquired;
+
+    /* XXX put interesting stats here! */
+
+    struct paint {
+	unsigned int count;
+	struct extents extents;
+	unsigned int operators[NUM_OPERATORS];
+	struct pattern source;
+	struct clip clip;
+	unsigned int noop;
+    } paint;
+
+    struct mask {
+	unsigned int count;
+	struct extents extents;
+	unsigned int operators[NUM_OPERATORS];
+	struct pattern source;
+	struct pattern mask;
+	struct clip clip;
+	unsigned int noop;
+    } mask;
+
+    struct fill {
+	unsigned int count;
+	struct extents extents;
+	unsigned int operators[NUM_OPERATORS];
+	struct pattern source;
+	struct path path;
+	unsigned int antialias[NUM_ANTIALIAS];
+	unsigned int fill_rule[NUM_FILL_RULE];
+	struct clip clip;
+	unsigned int noop;
+    } fill;
+
+    struct stroke {
+	unsigned int count;
+	struct extents extents;
+	unsigned int operators[NUM_OPERATORS];
+	unsigned int caps[NUM_CAPS];
+	unsigned int joins[NUM_CAPS];
+	unsigned int antialias[NUM_ANTIALIAS];
+	struct pattern source;
+	struct path path;
+	struct stat line_width;
+	struct clip clip;
+	unsigned int noop;
+    } stroke;
+
+    struct glyphs {
+	unsigned int count;
+	struct extents extents;
+	unsigned int operators[NUM_OPERATORS];
+	struct pattern source;
+	struct clip clip;
+	unsigned int noop;
+    } glyphs;
+};
+
+struct _cairo_device_observer {
+    cairo_device_t base;
+    cairo_device_t *target;
+
+    cairo_observation_t log;
+};
+
+struct _cairo_surface_observer {
+    cairo_surface_t base;
+    cairo_surface_t *target;
+
+    cairo_observation_t log;
+};
+
+static inline cairo_surface_t *
+_cairo_surface_observer_get_target (cairo_surface_t *surface)
+{
+    return ((cairo_surface_observer_t *) surface)->target;
+}
+
+static inline cairo_bool_t
+_cairo_surface_is_observer (cairo_surface_t *surface)
+{
+    return surface->backend->type == (cairo_surface_type_t)CAIRO_INTERNAL_SURFACE_TYPE_OBSERVER;
+}
+
+static inline cairo_bool_t
+_cairo_device_is_observer (cairo_device_t *device)
+{
+    return device->backend->type == (cairo_device_type_t)CAIRO_INTERNAL_DEVICE_TYPE_OBSERVER;
+}
+
+
+#endif /* CAIRO_SURFACE_SNAPSHOT_PRIVATE_H */
diff --git a/src/cairo-surface-observer.c b/src/cairo-surface-observer.c
new file mode 100644
index 000000000..ca1190954
--- /dev/null
+++ b/src/cairo-surface-observer.c
@@ -0,0 +1,1009 @@
+/* cairo - a vector graphics library with display and print output
+ *
+ * Copyright © 2011 Intel Corporation
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it either under the terms of the GNU Lesser General Public
+ * License version 2.1 as published by the Free Software Foundation
+ * (the "LGPL") or, at your option, under the terms of the Mozilla
+ * Public License Version 1.1 (the "MPL"). If you do not alter this
+ * notice, a recipient may use your version of this file under either
+ * the MPL or the LGPL.
+ *
+ * You should have received a copy of the LGPL along with this library
+ * in the file COPYING-LGPL-2.1; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
+ * You should have received a copy of the MPL along with this library
+ * in the file COPYING-MPL-1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
+ * OF ANY KIND, either express or implied. See the LGPL or the MPL for
+ * the specific language governing rights and limitations.
+ *
+ * The Original Code is the cairo graphics library.
+ *
+ * The Initial Developer of the Original Code is Intel Corporation.
+ *
+ * Contributor(s):
+ *      Chris Wilson <chris@chris-wilson.co.uk>
+ */
+
+#include "cairoint.h"
+
+#include "cairo-composite-rectangles-private.h"
+#include "cairo-error-private.h"
+#include "cairo-image-surface-private.h"
+#include "cairo-pattern-private.h"
+#include "cairo-output-stream-private.h"
+#include "cairo-surface-observer-private.h"
+#include "cairo-surface-subsurface-private.h"
+#include "cairo-reference-count-private.h"
+
+static const cairo_surface_backend_t _cairo_surface_observer_backend;
+
+/* observation/stats */
+
+static void init_stats (struct stat *s)
+{
+    s->min = HUGE_VAL;
+    s->max = -HUGE_VAL;
+}
+
+static void init_extents (struct extents *e)
+{
+    init_stats (&e->area);
+}
+
+static void init_pattern (struct pattern *p)
+{
+}
+
+static void init_path (struct path *p)
+{
+}
+
+static void init_clip (struct clip *c)
+{
+}
+
+static void init_paint (struct paint *p)
+{
+    init_extents (&p->extents);
+    init_pattern (&p->source);
+    init_clip (&p->clip);
+}
+
+static void init_mask (struct mask *m)
+{
+    init_extents (&m->extents);
+    init_pattern (&m->source);
+    init_pattern (&m->mask);
+    init_clip (&m->clip);
+}
+
+static void init_fill (struct fill *f)
+{
+    init_extents (&f->extents);
+    init_pattern (&f->source);
+    init_path (&f->path);
+    init_clip (&f->clip);
+}
+
+static void init_stroke (struct stroke *s)
+{
+    init_extents (&s->extents);
+    init_pattern (&s->source);
+    init_path (&s->path);
+    init_clip (&s->clip);
+}
+
+static void init_glyphs (struct glyphs *g)
+{
+    init_extents (&g->extents);
+    init_pattern (&g->source);
+    init_clip (&g->clip);
+}
+
+static void
+log_init (cairo_observation_t *log)
+{
+    memset (log, 0, sizeof(*log));
+
+    init_paint (&log->paint);
+    init_mask (&log->mask);
+    init_fill (&log->fill);
+    init_stroke (&log->stroke);
+    init_glyphs (&log->glyphs);
+}
+
+static cairo_surface_t*
+get_pattern_surface (const cairo_pattern_t *pattern)
+{
+    return ((cairo_surface_pattern_t *)pattern)->surface;
+}
+
+static void
+add_pattern (struct pattern *stats,
+	     const cairo_pattern_t *source,
+	     const cairo_surface_t *target)
+{
+    int classify;
+
+    switch (source->type) {
+    case CAIRO_PATTERN_TYPE_SURFACE:
+	if (get_pattern_surface (source)->type == target->type)
+	    classify = 0;
+	else if (get_pattern_surface (source)->type == CAIRO_SURFACE_TYPE_RECORDING)
+	    classify = 1;
+	else
+	    classify = 2;
+	break;
+    default:
+    case CAIRO_PATTERN_TYPE_SOLID:
+	classify = 3;
+	break;
+    case CAIRO_PATTERN_TYPE_LINEAR:
+	classify = 4;
+	break;
+    case CAIRO_PATTERN_TYPE_RADIAL:
+	classify = 5;
+	break;
+    case CAIRO_PATTERN_TYPE_MESH:
+	classify = 6;
+	break;
+    }
+    stats->type[classify]++;
+}
+
+static void
+add_path (struct path *stats,
+	  const cairo_path_fixed_t *path,
+	  cairo_bool_t is_fill)
+{
+    int classify;
+
+    /* XXX improve for stroke */
+    classify = -1;
+    if (is_fill) {
+	if (path->fill_is_empty)
+	    classify = 0;
+	else if (_cairo_path_fixed_fill_is_rectilinear (path))
+	    classify = 1;
+    } else {
+	if (_cairo_path_fixed_stroke_is_rectilinear (path))
+	    classify = 1;
+    }
+    if (classify == 1 && ! path->fill_maybe_region)
+	classify = 2;
+    classify = 3 + path->has_curve_to != 0;
+    stats->type[classify]++;
+}
+
+static void
+add_clip (struct clip *stats,
+	  const cairo_clip_t *clip)
+{
+    int classify;
+
+    if (clip == NULL)
+	classify = 0;
+    else if (_cairo_clip_is_region (clip))
+	classify = 1;
+    else if (clip->path == NULL)
+	classify = 2;
+    else
+	classify = 3;
+
+    stats->type[classify]++;
+
+}
+
+static void
+stats_add (struct stat *s, double v)
+{
+    if (v < s->min)
+	s->min = v;
+    if (v > s->max)
+	s->max = v;
+    s->sum += v;
+    s->sum_sq += v*v;
+    s->count++;
+}
+
+static void
+add_extents (struct extents *stats,
+	     const cairo_composite_rectangles_t *extents)
+{
+    const cairo_rectangle_int_t *r = extents->is_bounded ? &extents->bounded :&extents->unbounded;
+    stats_add (&stats->area, r->width * r->height);
+    stats->bounded += extents->is_bounded != 0;
+    stats->unbounded += extents->is_bounded == 0;
+}
+
+/* device interface */
+
+static void
+_cairo_device_observer_lock (void *_device)
+{
+    cairo_device_observer_t *device = (cairo_device_observer_t *) _device;
+    cairo_device_acquire (device->target);
+}
+
+static void
+_cairo_device_observer_unlock (void *_device)
+{
+    cairo_device_observer_t *device = (cairo_device_observer_t *) _device;
+    cairo_device_release (device->target);
+}
+
+static cairo_status_t
+_cairo_device_observer_flush (void *_device)
+{
+    cairo_device_observer_t *device = (cairo_device_observer_t *) _device;
+
+    if (device->target == NULL)
+	return CAIRO_STATUS_SUCCESS;
+
+    cairo_device_flush (device->target);
+    return device->target->status;
+}
+
+static void
+_cairo_device_observer_finish (void *_device)
+{
+    cairo_device_observer_t *device = (cairo_device_observer_t *) _device;
+    cairo_device_finish (device->target);
+}
+
+static void
+_cairo_device_observer_destroy (void *_device)
+{
+    cairo_device_observer_t *device = (cairo_device_observer_t *) _device;
+    cairo_device_destroy (device->target);
+    free (device);
+}
+
+static const cairo_device_backend_t _cairo_device_observer_backend = {
+    CAIRO_INTERNAL_DEVICE_TYPE_OBSERVER,
+
+    _cairo_device_observer_lock,
+    _cairo_device_observer_unlock,
+
+    _cairo_device_observer_flush,
+    _cairo_device_observer_finish,
+    _cairo_device_observer_destroy,
+};
+
+static cairo_device_t *
+_cairo_device_create_observer_internal (cairo_device_t *target)
+{
+    cairo_device_observer_t *device;
+
+    device = malloc (sizeof (cairo_device_observer_t));
+    if (unlikely (device == NULL))
+	return _cairo_device_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));
+
+    _cairo_device_init (&device->base, &_cairo_device_observer_backend);
+    device->target = cairo_device_reference (target);
+
+    log_init (&device->log);
+
+    return &device->base;
+}
+
+/* surface interface */
+
+static cairo_device_observer_t *
+to_device (cairo_surface_observer_t *suface)
+{
+    return (cairo_device_observer_t *)suface->base.device;
+}
+
+static cairo_surface_t *
+_cairo_surface_create_observer_internal (cairo_device_t *device,
+					 cairo_surface_t *target)
+{
+    cairo_surface_observer_t *surface;
+
+    surface = malloc (sizeof (cairo_surface_observer_t));
+    if (unlikely (surface == NULL))
+	return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));
+
+    _cairo_surface_init (&surface->base,
+			 &_cairo_surface_observer_backend, device,
+			 target->content);
+
+    log_init (&surface->log);
+
+    surface->target = cairo_surface_reference (target);
+    surface->base.type = surface->target->type;
+    surface->base.is_clear = surface->target->is_clear;
+
+    surface->log.num_surfaces++;
+    to_device (surface)->log.num_surfaces++;
+
+    return &surface->base;
+}
+
+
+static cairo_status_t
+_cairo_surface_observer_finish (void *abstract_surface)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+
+    cairo_surface_destroy (surface->target);
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+static cairo_surface_t *
+_cairo_surface_observer_create_similar (void *abstract_other,
+					cairo_content_t content,
+					int width, int height)
+{
+    cairo_surface_observer_t *other = abstract_other;
+    cairo_surface_t *target, *surface;
+
+    target = NULL;
+    if (other->target->backend->create_similar)
+	target = other->target->backend->create_similar (other->target, content,
+							 width, height);
+    if (target == NULL)
+	target = _cairo_image_surface_create_with_content (content,
+							   width, height);
+
+    surface = _cairo_surface_create_observer_internal (other->base.device,
+						       target);
+    cairo_surface_destroy (target);
+
+    return surface;
+}
+
+static cairo_surface_t *
+_cairo_surface_observer_create_similar_image (void *other,
+					      cairo_format_t format,
+					      int width, int height)
+{
+    cairo_surface_observer_t *surface = other;
+
+    if (surface->target->backend->create_similar_image)
+	return surface->target->backend->create_similar_image (surface->target,
+							       format,
+							       width, height);
+
+    return NULL;
+}
+
+static cairo_surface_t *
+_cairo_surface_observer_map_to_image (void *abstract_surface,
+				      const cairo_rectangle_int_t *extents)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+
+    if (surface->target->backend->map_to_image == NULL)
+	return NULL;
+
+    return surface->target->backend->map_to_image (surface->target, extents);
+}
+
+static cairo_int_status_t
+_cairo_surface_observer_unmap_image (void *abstract_surface,
+				     cairo_image_surface_t *image)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+
+    if (surface->target->backend->unmap_image == NULL)
+	return CAIRO_INT_STATUS_UNSUPPORTED;
+
+    return surface->target->backend->unmap_image (surface->target, image);
+}
+
+static cairo_int_status_t
+_cairo_surface_observer_paint (void *abstract_surface,
+			       cairo_operator_t op,
+			       const cairo_pattern_t *source,
+			       const cairo_clip_t *clip)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+    cairo_device_observer_t *device = to_device (surface);
+    cairo_composite_rectangles_t composite;
+    cairo_rectangle_int_t extents;
+    cairo_int_status_t status;
+
+    /* XXX device locking */
+
+    surface->log.paint.count++;
+    surface->log.paint.operators[op]++;
+    add_pattern (&surface->log.paint.source, source, surface->target);
+    add_clip (&surface->log.paint.clip, clip);
+
+    device->log.paint.count++;
+    device->log.paint.operators[op]++;
+    add_pattern (&device->log.paint.source, source, surface->target);
+    add_clip (&device->log.paint.clip, clip);
+
+    _cairo_surface_get_extents (surface->target, &extents);
+    status = _cairo_composite_rectangles_init_for_paint (&composite,
+							 &extents,
+							 op, source,
+							 clip);
+    if (unlikely (status)) {
+	surface->log.paint.noop++;
+	device->log.paint.noop++;
+	return status;
+    }
+
+    add_extents (&surface->log.paint.extents, &composite);
+    add_extents (&device->log.paint.extents, &composite);
+    _cairo_composite_rectangles_fini (&composite);
+
+    /* XXX time? */
+    return _cairo_surface_paint (surface->target,
+				 op, source,
+				 clip);
+}
+
+static cairo_int_status_t
+_cairo_surface_observer_mask (void *abstract_surface,
+			      cairo_operator_t op,
+			      const cairo_pattern_t *source,
+			      const cairo_pattern_t *mask,
+			      const cairo_clip_t *clip)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+    cairo_device_observer_t *device = to_device (surface);
+    cairo_composite_rectangles_t composite;
+    cairo_rectangle_int_t extents;
+    cairo_int_status_t status;
+
+    surface->log.mask.count++;
+    surface->log.mask.operators[op]++;
+    add_pattern (&surface->log.mask.source, source, surface->target);
+    add_pattern (&surface->log.mask.mask, mask, surface->target);
+    add_clip (&surface->log.mask.clip, clip);
+
+    device->log.mask.count++;
+    device->log.mask.operators[op]++;
+    add_pattern (&device->log.mask.source, source, surface->target);
+    add_pattern (&device->log.mask.mask, mask, surface->target);
+    add_clip (&device->log.mask.clip, clip);
+
+    _cairo_surface_get_extents (surface->target, &extents);
+    status = _cairo_composite_rectangles_init_for_mask (&composite,
+							&extents,
+							op, source, mask,
+							clip);
+    if (unlikely (status)) {
+	surface->log.mask.noop++;
+	device->log.mask.noop++;
+	return status;
+    }
+
+    add_extents (&surface->log.mask.extents, &composite);
+    add_extents (&device->log.mask.extents, &composite);
+    _cairo_composite_rectangles_fini (&composite);
+
+    return _cairo_surface_mask (surface->target,
+				op, source, mask,
+				clip);
+}
+
+static cairo_int_status_t
+_cairo_surface_observer_fill (void			*abstract_surface,
+			      cairo_operator_t		op,
+			      const cairo_pattern_t	*source,
+			      const cairo_path_fixed_t	*path,
+			      cairo_fill_rule_t		fill_rule,
+			      double			 tolerance,
+			      cairo_antialias_t		antialias,
+			      const cairo_clip_t	*clip)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+    cairo_device_observer_t *device = to_device (surface);
+    cairo_composite_rectangles_t composite;
+    cairo_rectangle_int_t extents;
+    cairo_int_status_t status;
+
+    surface->log.fill.count++;
+    surface->log.fill.operators[op]++;
+    surface->log.fill.fill_rule[fill_rule]++;
+    surface->log.fill.antialias[antialias]++;
+    add_pattern (&surface->log.fill.source, source, surface->target);
+    add_path (&surface->log.fill.path, path, TRUE);
+    add_clip (&surface->log.fill.clip, clip);
+
+    device->log.fill.count++;
+    device->log.fill.operators[op]++;
+    device->log.fill.fill_rule[fill_rule]++;
+    device->log.fill.antialias[antialias]++;
+    add_pattern (&device->log.fill.source, source, surface->target);
+    add_path (&device->log.fill.path, path, TRUE);
+    add_clip (&device->log.fill.clip, clip);
+
+    _cairo_surface_get_extents (surface->target, &extents);
+    status = _cairo_composite_rectangles_init_for_fill (&composite,
+							&extents,
+							op, source, path,
+							clip);
+    if (unlikely (status)) {
+	surface->log.fill.noop++;
+	device->log.fill.noop++;
+	return status;
+    }
+
+    add_extents (&surface->log.fill.extents, &composite);
+    add_extents (&device->log.fill.extents, &composite);
+    _cairo_composite_rectangles_fini (&composite);
+
+    return _cairo_surface_fill (surface->target,
+				op, source, path,
+				fill_rule, tolerance, antialias,
+				clip);
+}
+
+static cairo_int_status_t
+_cairo_surface_observer_stroke (void				*abstract_surface,
+				cairo_operator_t		 op,
+				const cairo_pattern_t		*source,
+				const cairo_path_fixed_t	*path,
+				const cairo_stroke_style_t	*style,
+				const cairo_matrix_t		*ctm,
+				const cairo_matrix_t		*ctm_inverse,
+				double				 tolerance,
+				cairo_antialias_t		 antialias,
+				const cairo_clip_t		*clip)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+    cairo_device_observer_t *device = to_device (surface);
+    cairo_composite_rectangles_t composite;
+    cairo_rectangle_int_t extents;
+    cairo_int_status_t status;
+
+    surface->log.stroke.count++;
+    surface->log.stroke.operators[op]++;
+    surface->log.stroke.antialias[antialias]++;
+    add_pattern (&surface->log.stroke.source, source, surface->target);
+    add_path (&surface->log.stroke.path, path, FALSE);
+    add_clip (&surface->log.stroke.clip, clip);
+
+    device->log.stroke.count++;
+    device->log.stroke.operators[op]++;
+    device->log.stroke.antialias[antialias]++;
+    add_pattern (&device->log.stroke.source, source, surface->target);
+    add_path (&device->log.stroke.path, path, FALSE);
+    add_clip (&device->log.stroke.clip, clip);
+
+    _cairo_surface_get_extents (surface->target, &extents);
+    status = _cairo_composite_rectangles_init_for_stroke (&composite,
+							  &extents,
+							  op, source,
+							  path, style, ctm,
+							  clip);
+    if (unlikely (status)) {
+	surface->log.stroke.noop++;
+	device->log.stroke.noop++;
+	return status;
+    }
+
+    add_extents (&surface->log.stroke.extents, &composite);
+    add_extents (&device->log.stroke.extents, &composite);
+    _cairo_composite_rectangles_fini (&composite);
+
+    return _cairo_surface_stroke (surface->target,
+				  op, source, path,
+				  style, ctm, ctm_inverse,
+				  tolerance, antialias,
+				  clip);
+}
+
+static cairo_int_status_t
+_cairo_surface_observer_glyphs (void			*abstract_surface,
+				cairo_operator_t	 op,
+				const cairo_pattern_t	*source,
+				cairo_glyph_t		*glyphs,
+				int			 num_glyphs,
+				cairo_scaled_font_t	*scaled_font,
+				const cairo_clip_t		*clip,
+				int *remaining_glyphs)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+    cairo_device_observer_t *device = to_device (surface);
+    cairo_composite_rectangles_t composite;
+    cairo_rectangle_int_t extents;
+    cairo_int_status_t status;
+
+    surface->log.glyphs.count++;
+    surface->log.glyphs.operators[op]++;
+    add_pattern (&surface->log.glyphs.source, source, surface->target);
+    add_clip (&surface->log.glyphs.clip, clip);
+
+    device->log.glyphs.count++;
+    device->log.glyphs.operators[op]++;
+    add_pattern (&device->log.glyphs.source, source, surface->target);
+    add_clip (&device->log.glyphs.clip, clip);
+
+    _cairo_surface_get_extents (surface->target, &extents);
+    status = _cairo_composite_rectangles_init_for_glyphs (&composite,
+							  &extents,
+							  op, source,
+							  scaled_font,
+							  glyphs, num_glyphs,
+							  clip,
+							  NULL);
+    if (unlikely (status)) {
+	surface->log.glyphs.noop++;
+	device->log.glyphs.noop++;
+	return status;
+    }
+
+    add_extents (&surface->log.glyphs.extents, &composite);
+    add_extents (&device->log.glyphs.extents, &composite);
+    _cairo_composite_rectangles_fini (&composite);
+
+    *remaining_glyphs = 0;
+    return _cairo_surface_show_text_glyphs (surface->target, op, source,
+					    NULL, 0,
+					    glyphs, num_glyphs,
+					    NULL, 0, 0,
+					    scaled_font,
+					    clip);
+}
+
+static cairo_status_t
+_cairo_surface_observer_flush (void *abstract_surface)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+
+    cairo_surface_flush (surface->target);
+    return surface->target->status;
+}
+
+static cairo_status_t
+_cairo_surface_observer_mark_dirty (void *abstract_surface,
+				      int x, int y,
+				      int width, int height)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+    cairo_status_t status;
+
+    printf ("mark-dirty (%d, %d) x (%d, %d)\n", x, y, width, height);
+
+    status = CAIRO_STATUS_SUCCESS;
+    if (surface->target->backend->mark_dirty_rectangle)
+	status = surface->target->backend->mark_dirty_rectangle (surface->target,
+						       x,y, width,height);
+
+    return status;
+}
+
+static cairo_int_status_t
+_cairo_surface_observer_copy_page (void *abstract_surface)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+    cairo_status_t status;
+
+    status = CAIRO_STATUS_SUCCESS;
+    if (surface->target->backend->copy_page)
+	status = surface->target->backend->copy_page (surface->target);
+
+    return status;
+}
+
+static cairo_int_status_t
+_cairo_surface_observer_show_page (void *abstract_surface)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+    cairo_status_t status;
+
+    status = CAIRO_STATUS_SUCCESS;
+    if (surface->target->backend->show_page)
+	status = surface->target->backend->show_page (surface->target);
+
+    return status;
+}
+
+static cairo_bool_t
+_cairo_surface_observer_get_extents (void *abstract_surface,
+				     cairo_rectangle_int_t *extents)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+    return _cairo_surface_get_extents (surface->target, extents);
+}
+
+static void
+_cairo_surface_observer_get_font_options (void *abstract_surface,
+					  cairo_font_options_t *options)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+
+    if (surface->target->backend->get_font_options != NULL)
+	surface->target->backend->get_font_options (surface->target, options);
+}
+
+static cairo_status_t
+_cairo_surface_observer_acquire_source_image (void                    *abstract_surface,
+						cairo_image_surface_t  **image_out,
+						void                   **image_extra)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+
+    surface->log.num_sources_acquired++;
+    to_device (surface)->log.num_sources_acquired++;
+
+    return _cairo_surface_acquire_source_image (surface->target,
+						image_out, image_extra);
+}
+
+static void
+_cairo_surface_observer_release_source_image (void                   *abstract_surface,
+						cairo_image_surface_t  *image,
+						void                   *image_extra)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+
+    return _cairo_surface_release_source_image (surface->target, image, image_extra);
+}
+
+static cairo_surface_t *
+_cairo_surface_observer_snapshot (void *abstract_surface)
+{
+    cairo_surface_observer_t *surface = abstract_surface;
+
+    printf ("taking snapshot\n");
+
+    /* XXX hook onto the snapshot so that we measure number of reads */
+
+    if (surface->target->backend->snapshot)
+	return surface->target->backend->snapshot (surface->target);
+
+    return NULL;
+}
+
+static cairo_t *
+_cairo_surface_observer_create_context(void *target)
+{
+    cairo_surface_observer_t *surface = target;
+
+    if (_cairo_surface_is_subsurface (&surface->base))
+	surface = (cairo_surface_observer_t *)
+	    _cairo_surface_subsurface_get_target (&surface->base);
+
+    surface->log.num_contexts++;
+    to_device (surface)->log.num_contexts++;
+
+    return surface->target->backend->create_context (target);
+}
+
+static const cairo_surface_backend_t _cairo_surface_observer_backend = {
+    CAIRO_INTERNAL_SURFACE_TYPE_OBSERVER,
+    _cairo_surface_observer_finish,
+
+    _cairo_surface_observer_create_context,
+
+    _cairo_surface_observer_create_similar,
+    _cairo_surface_observer_create_similar_image,
+    _cairo_surface_observer_map_to_image,
+    _cairo_surface_observer_unmap_image,
+
+    _cairo_surface_observer_acquire_source_image,
+    _cairo_surface_observer_release_source_image,
+
+    NULL, NULL, /* acquire, release dest */
+    NULL, /* clone similar */
+    NULL, /* composite */
+    NULL, /* fill rectangles */
+    NULL, /* composite trapezoids */
+    NULL, /* create span renderer */
+    NULL, /* check span renderer */
+
+    _cairo_surface_observer_copy_page,
+    _cairo_surface_observer_show_page,
+
+    _cairo_surface_observer_get_extents,
+    NULL, /* old_show_glyphs */
+    _cairo_surface_observer_get_font_options,
+    _cairo_surface_observer_flush,
+    _cairo_surface_observer_mark_dirty,
+    NULL, /* font_fini */
+    NULL, /* glyph_fini */
+
+    _cairo_surface_observer_paint,
+    _cairo_surface_observer_mask,
+    _cairo_surface_observer_stroke,
+    _cairo_surface_observer_fill,
+    _cairo_surface_observer_glyphs,
+
+    _cairo_surface_observer_snapshot,
+};
+
+/**
+ * cairo_surface_create_observer:
+ * @target: an existing surface for which the observer will watch
+ *
+ * Create a new surface that exists solely to watch another is doing. In
+ * the process it will log operations and times, which are fast, which are
+ * slow, which are frequent, etc.
+ *
+ * Return value: a pointer to the newly allocated surface. The caller
+ * owns the surface and should call cairo_surface_destroy() when done
+ * with it.
+ *
+ * This function always returns a valid pointer, but it will return a
+ * pointer to a "nil" surface if @other is already in an error state
+ * or any other error occurs.
+ *
+ * Since: 1.12
+ **/
+cairo_surface_t *
+cairo_surface_create_observer (cairo_surface_t *target)
+{
+    cairo_device_t *device;
+    cairo_surface_t *surface;
+
+    if (unlikely (target->status))
+	return _cairo_surface_create_in_error (target->status);
+    if (unlikely (target->finished))
+	return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_SURFACE_FINISHED));
+
+    device = _cairo_device_create_observer_internal (target->device);
+    if (unlikely (device->status))
+	return _cairo_surface_create_in_error (device->status);
+
+    surface = _cairo_surface_create_observer_internal (device, target);
+    cairo_device_destroy (device);
+
+    return surface;
+}
+
+static void
+print_extents (cairo_output_stream_t *stream, const struct extents *e)
+{
+    _cairo_output_stream_printf (stream,
+				 "  extents: total %g, avg %g [unbounded %d]\n",
+				 e->area.sum,
+				 e->area.sum / e->area.count,
+				 e->unbounded);
+}
+
+static void
+print_pattern (cairo_output_stream_t *stream,
+	       const char *name,
+	       const struct pattern *p)
+{
+    _cairo_output_stream_printf (stream,
+				 "  %s: %d native, %d record, %d other surface, %d solid, %d linear, %d radial, %d mesh\n",
+				 name,
+				 p->type[0],
+				 p->type[1],
+				 p->type[2],
+				 p->type[3],
+				 p->type[4],
+				 p->type[5],
+				 p->type[6]);
+}
+
+static void
+print_path (cairo_output_stream_t *stream,
+	    const struct path *p)
+{
+    _cairo_output_stream_printf (stream,
+				 "  path: %d empty, %d pixel-aligned, %d rectilinear, %d straight, %d curved\n",
+				 p->type[0],
+				 p->type[1],
+				 p->type[2],
+				 p->type[3],
+				 p->type[4]);
+}
+
+static void
+print_clip (cairo_output_stream_t *stream, const struct clip *c)
+{
+    _cairo_output_stream_printf (stream,
+				 "  clip: %d none, %d region, %d boxes, %d general path\n",
+				 c->type[0],
+				 c->type[1],
+				 c->type[2],
+				 c->type[3]);
+}
+
+static void
+_cairo_observation_print (cairo_output_stream_t *stream,
+				  cairo_observation_t *log)
+{
+    _cairo_output_stream_printf (stream, "surfaces: %d\n",
+				 log->num_surfaces);
+    _cairo_output_stream_printf (stream, "contexts: %d\n",
+				 log->num_contexts);
+    _cairo_output_stream_printf (stream, "sources acquired: %d\n",
+				 log->num_sources_acquired);
+
+    _cairo_output_stream_printf (stream, "paint: count %d [no-op %d]\n",
+				 log->paint.count, log->paint.noop);
+    if (log->paint.count) {
+	print_extents (stream, &log->paint.extents);
+	print_pattern (stream, "source", &log->paint.source);
+	print_clip (stream, &log->paint.clip);
+    }
+
+    _cairo_output_stream_printf (stream, "mask: count %d [no-op %d]\n",
+				 log->mask.count, log->mask.noop);
+    if (log->mask.count) {
+	print_extents (stream, &log->mask.extents);
+	print_pattern (stream, "source", &log->mask.source);
+	print_pattern (stream, "mask", &log->mask.mask);
+	print_clip (stream, &log->mask.clip);
+    }
+
+    _cairo_output_stream_printf (stream, "fill: count %d [no-op %d]\n",
+				 log->fill.count, log->fill.noop);
+    if (log->fill.count) {
+	print_extents (stream, &log->fill.extents);
+	print_pattern (stream, "source", &log->fill.source);
+	print_path (stream, &log->fill.path);
+	print_clip (stream, &log->fill.clip);
+    }
+
+    _cairo_output_stream_printf (stream, "stroke: count %d [no-op %d]\n",
+				 log->stroke.count, log->stroke.noop);
+    if (log->stroke.count) {
+	print_extents (stream, &log->stroke.extents);
+	print_pattern (stream, "source", &log->stroke.source);
+	print_path (stream, &log->stroke.path);
+	print_clip (stream, &log->stroke.clip);
+    }
+
+    _cairo_output_stream_printf (stream, "glyphs: count %d [no-op %d]\n",
+				 log->glyphs.count, log->glyphs.noop);
+    if (log->glyphs.count) {
+	print_extents (stream, &log->glyphs.extents);
+	print_pattern (stream, "source", &log->glyphs.source);
+	print_clip (stream, &log->glyphs.clip);
+    }
+}
+
+void
+cairo_surface_observer_print (cairo_surface_t *abstract_surface,
+			      cairo_write_func_t write_func,
+			      void *closure)
+{
+    cairo_output_stream_t *stream;
+    cairo_surface_observer_t *surface;
+
+    if (unlikely (CAIRO_REFERENCE_COUNT_IS_INVALID (&abstract_surface->ref_count)))
+	return;
+
+    if (! _cairo_surface_is_observer (abstract_surface))
+	return;
+
+    surface = (cairo_surface_observer_t *) abstract_surface;
+
+    stream = _cairo_output_stream_create (write_func, NULL, closure);
+    _cairo_observation_print (stream, &surface->log);
+    _cairo_output_stream_destroy (stream);
+}
+
+void
+cairo_device_observer_print (cairo_device_t *abstract_device,
+			     cairo_write_func_t write_func,
+			     void *closure)
+{
+    cairo_output_stream_t *stream;
+    cairo_device_observer_t *device;
+
+    if (unlikely (CAIRO_REFERENCE_COUNT_IS_INVALID (&abstract_device->ref_count)))
+	return;
+
+    if (! _cairo_device_is_observer (abstract_device))
+	return;
+
+    device = (cairo_device_observer_t *) abstract_device;
+
+    stream = _cairo_output_stream_create (write_func, NULL, closure);
+    _cairo_observation_print (stream, &device->log);
+    _cairo_output_stream_destroy (stream);
+}
diff --git a/src/cairo-surface.c b/src/cairo-surface.c
index 236ab425b..6851ca92d 100644
--- a/src/cairo-surface.c
+++ b/src/cairo-surface.c
@@ -562,6 +562,8 @@ cairo_surface_create_similar_image (cairo_surface_t  *other,
 				    int		width,
 				    int		height)
 {
+    cairo_surface_t *image;
+
     if (other->status)
 	return _cairo_surface_create_in_error (other->status);
     if (unlikely (other->finished))
@@ -572,11 +574,13 @@ cairo_surface_create_similar_image (cairo_surface_t  *other,
     if (unlikely (! CAIRO_FORMAT_VALID (format)))
 	return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_INVALID_FORMAT));
 
+    image = NULL;
     if (other->backend->create_similar_image)
-	return other->backend->create_similar_image (other,
-						    format, width, height);
-
-    return cairo_image_surface_create (format, width, height);
+	image = other->backend->create_similar_image (other,
+						      format, width, height);
+    if (image == NULL)
+	image = cairo_image_surface_create (format, width, height);
+    return image;
 }
 
 /**
diff --git a/src/cairo-types-private.h b/src/cairo-types-private.h
index 4933cf260..0b57ec28c 100644
--- a/src/cairo-types-private.h
+++ b/src/cairo-types-private.h
@@ -82,6 +82,7 @@ typedef struct _cairo_scaled_font_subsets cairo_scaled_font_subsets_t;
 typedef struct _cairo_solid_pattern cairo_solid_pattern_t;
 typedef struct _cairo_surface_attributes cairo_surface_attributes_t;
 typedef struct _cairo_surface_backend cairo_surface_backend_t;
+typedef struct _cairo_surface_observer cairo_surface_observer_t;
 typedef struct _cairo_surface_snapshot cairo_surface_snapshot_t;
 typedef struct _cairo_surface_subsurface cairo_surface_subsurface_t;
 typedef struct _cairo_surface_wrapper cairo_surface_wrapper_t;
@@ -231,6 +232,7 @@ typedef enum _cairo_internal_surface_type {
     CAIRO_INTERNAL_SURFACE_TYPE_SNAPSHOT = 0x1000,
     CAIRO_INTERNAL_SURFACE_TYPE_PAGINATED,
     CAIRO_INTERNAL_SURFACE_TYPE_ANALYSIS,
+    CAIRO_INTERNAL_SURFACE_TYPE_OBSERVER,
     CAIRO_INTERNAL_SURFACE_TYPE_TEST_FALLBACK,
     CAIRO_INTERNAL_SURFACE_TYPE_TEST_PAGINATED,
     CAIRO_INTERNAL_SURFACE_TYPE_TEST_WRAPPING,
@@ -238,6 +240,10 @@ typedef enum _cairo_internal_surface_type {
     CAIRO_INTERNAL_SURFACE_TYPE_TYPE3_GLYPH
 } cairo_internal_surface_type_t;
 
+typedef enum _cairo_internal_device_type {
+    CAIRO_INTERNAL_DEVICE_TYPE_OBSERVER = 0x1000,
+} cairo_device_surface_type_t;
+
 #define CAIRO_HAS_TEST_PAGINATED_SURFACE 1
 #define CAIRO_HAS_TEST_NULL_SURFACE 1
 #define CAIRO_HAS_TEST_WRAPPING_SURFACE 1
diff --git a/src/cairo.h b/src/cairo.h
index 9d788cc88..bf2e232bc 100644
--- a/src/cairo.h
+++ b/src/cairo.h
@@ -2095,6 +2095,19 @@ cairo_surface_create_for_rectangle (cairo_surface_t	*target,
                                     double		 width,
                                     double		 height);
 
+cairo_public cairo_surface_t *
+cairo_surface_create_observer (cairo_surface_t *target);
+
+cairo_public void
+cairo_surface_observer_print (cairo_surface_t *surface,
+			      cairo_write_func_t write_func,
+			      void *closure);
+
+cairo_public void
+cairo_device_observer_print (cairo_device_t *device,
+			     cairo_write_func_t write_func,
+			     void *closure);
+
 cairo_public cairo_surface_t *
 cairo_surface_reference (cairo_surface_t *surface);