GObject is slow

[Alexander Larsson <alla lysator liu se>]

I've been doing some profiling of GtkFB to find out bottlenecks in the
rasterization code. But looking at the profiles show that rasterization
isn't even at the top. Instead i see a lot of functions from the GObject
type checking code.

Here is the top of a profile on a testgtk run using GtkFB @ 1024x768
16bit. glib+pango+gtk+ is compiled with -O2 -g  and -DG_DISABLE_ASSERT
-DG_DISABLE_CHECKS -DGTK_NO_CHECK_CASTS.

I basically opened a few test in testgtk, scrolled some scrollbars,
clicked some buttons etc. I think i use the following tests: button,
checkbutton, clist, color selector, ctree, cursor, dialog, filesel, gamma
curve, image notebook and styles.

The last two columns are calculated by me and is % time except
g_main_poll.

Function Name                                     calls   func%  func(ms)    f+c%   f+c(ms)    f-p%   f+c-p%

g_main_poll                                       23786  61.970     77463  62.035     77545    n/a 
gdk_fb_draw_drawable_memmove                      32678   6.194      7742   6.194      7742    16.3%  16.3%
g_type_check_flags                              2773957   2.256      2819   4.912      6140    5.9 %  12.9%
g_type_check_instance_cast                      2444663   2.227      2783   8.769     10961    5.9 %  23.1%
LOOKUP_TYPE_NODE                                9563625   2.069      2586   2.069      2586    5.4 %  5.5 %
gdk_fb_draw_drawable_generic                      43009   1.752      2189   3.252      4065    4.6 %  8.6 %
g_type_conforms_to                              2706083   1.700      2125   2.467      3083    4.5 %  6.5 %
type_node_fundamental_info                      2736730   1.440      1800   2.017      2520    3.8 %  5.3 %
call_gmon_start                                 2048582   1.404      1755  83.075    103845    3.7 %  
g_free                                          1686235   0.944      1179   0.944      1179    2.5 %
gdk_fb_drawable_set_pixel_16                    2015218   0.694       867   0.694       867    1.8 %
gdk_region_destroy                               623334   0.610       762   1.260      1574    1.6 %
pango_fb_font_get_glyph_info                     335858   0.599       748   3.685      4606    1.6 %  9.7 %
gdk_fb_drawable_get_pixel                       2124696   0.596       744   0.596       744    1.6 %
pango_fb_font_set_size                           629307   0.582       726   2.792      3489    1.5 %  7.3 %
miRegionOp                                       237907   0.577       720   1.159      1449    1.5 %
gdk_region_rectangle                             583661   0.564       704   1.261      1576    1.5 %
gdk_fb_clip_region                                79361   0.555       693   3.017      3771    1.5 %
pango_fb_font_get_glyph_extents                  287358   0.498       622   6.015      7518    1.3 %  15.8%
list_fonts                                            4   0.459       574   0.461       575    1.2 %
gdk_fb_draw_drawable_3                            95739   0.423       528  11.724     14655    1.1 %  30.8%
gdk_fb_fill_span_simple_16                       280496   0.385       481   0.385       481    1.0 %
g_main_iterate                                    23786   0.363       453  98.822    123529    1.0 %
gdk_fb_fill_spans                                 36867   0.348       434   4.469      5585    0.9 %  11.8%
pango_fb_font_get_type                          1496613   0.323       403   0.323       404    
g_hash_table_lookup_node                         427700   0.306       383   0.422       527 
gdk_fb_drawable_get_color_16                     460285   0.291       363   0.291       363 
find_char                                        238433   0.274       342   1.131      1414 
g_type_instance_conforms_to                      367544   0.270       337   0.975      1218 
gdk_region_intersect                             272430   0.251       313   1.043      1304 
g_hash_table_lookup                              424545   0.209       261   0.626       783 
gtk_signal_emitv                                  37326   0.209       260  80.773    100967 
paint_ring                                           16   0.165       206   0.410       512 


/ Alex