I have reported a bug to cairo-bugs mailing list For more information, please visit https://bugs.freedesktop.org/show_bug.cgi?id=66871 Are both pango and cairo thread-safe?
2013/7/13 Hodong Kim <[email protected]> > Hello. > > I am developing evince backend for hwp document file. > I want to apply pango layout to evince hwp backend. > > so, I tried to apply "Example 1. Using Pango with Cairo" > (https://developer.gnome.org/pango/stable/pango-Cairo-Rendering.html) > to SAMPLE evince backend and EXAMPLE library. > > /* Example 1. Using Pango with Cairo */ > /* https://developer.gnome.org/pango/1.34/pango-Cairo-Rendering.html */ > #include <math.h> > #include <pango/pangocairo.h> > static void > draw_text (cairo_t *cr) > { > #define RADIUS 150 > #define N_WORDS 10 > #define FONT "Sans Bold 27" > PangoLayout *layout; > PangoFontDescription *desc; > int i; > /* Center coordinates on the middle of the region we are drawing > */ > cairo_translate (cr, RADIUS, RADIUS); > /* Create a PangoLayout, set the font and text */ > layout = pango_cairo_create_layout (cr); > pango_layout_set_text (layout, "Text", -1); > desc = pango_font_description_from_string (FONT); > pango_layout_set_font_description (layout, desc); > pango_font_description_free (desc); > /* Draw the layout N_WORDS times in a circle */ > for (i = 0; i < N_WORDS; i++) > { > int width, height; > double angle = (360. * i) / N_WORDS; > double red; > cairo_save (cr); > /* Gradient from red at angle == 60 to blue at angle == 240 */ > red = (1 + cos ((angle - 60) * G_PI / 180.)) / 2; > cairo_set_source_rgb (cr, red, 0, 1.0 - red); > cairo_rotate (cr, angle * G_PI / 180.); > /* Inform Pango to re-layout the text with the new transformation */ > pango_cairo_update_layout (cr, layout); > pango_layout_get_size (layout, &width, &height); > cairo_move_to (cr, - ((double)width / PANGO_SCALE) / 2, - RADIUS); > pango_cairo_show_layout (cr, layout); > cairo_restore (cr); > } > /* free the layout object */ > g_object_unref (layout); > } > > gboolean example_page_render (ExamplePage *page, cairo_t *cr) > { > g_return_val_if_fail (EXAMPLE_IS_PAGE (page), FALSE); > draw_text (cr); > return TRUE; > } > > then opened the sample text file from the terminal with evince > but segmentation fault occurred intermittently. > > I cannot understand the behavior that when I use cairo it works fine > but when I use pango segmentation fault occurs. > > Is it because of pango_cairo_font_map_get_default() or thread ? > but considering ev_job_render_run (EvJob *job) in libview/ev-jobs.c > > ev_document_fc_mutex_lock () > ... > job_render->surface = ev_document_render (job->document, rc); > ... > ev_document_fc_mutex_unlock () > > Although pango is thread-safe since 1.32.6 > when I tested in pango 1.30.0 / 1.32.5 / 1.34.1 / 1.35.0 > segmentation fault alse occurred in all cases. > > I don't know why. > Please advise me how to do. > > To test libexample and evince-sample-backend please follow the below steps. > > Step 1. Downloads the attachment and extract. > > evince-sample-backend and libexample will be created. > > Step 2. compile and install libexample > > cd libexample > ./autogen.sh > make > sudo make install > sudo ldconfig > cd .. > > Step 3. compile and install evince-sample-backend > > cd evince-sample-backend > ./autogen.sh > make > sudo make install > sudo ldconfig > > Step 4. open the any text file from the terminal with evince many times. > > $ evince any.txt > > > My current environment: > debian wheezy > evince 3.4.0-3.1 > libpango1.0-0 1.30.0-1 > libcairo2 1.12.2-3 >
_______________________________________________ gtk-i18n-list mailing list [email protected] https://mail.gnome.org/mailman/listinfo/gtk-i18n-list
