In order to avoid recursive dead-locks where whilst one thread holds the
scaled font lock and is waiting on the XLockDisplay() another thread catches
the CloseDisplay and then tries to acquire the scaled font lock, we drop
the list mutex whilst processing the callbacks.
Do not initialize font options when setting up the
cairo_xlib_screen_info_t corresponding to the display itself and not
associated with any screen. This avoids a potential NULL dereferences.
(Fixes https://bugs.freedesktop.org/show_bug.cgi?id=10517)
pixman_format_t is a simple structure used in short-term allocations and
suitable for on-stack allocation.
Killing the pixman_format_create()/pixman_format_destroy() pairs avoid
around 6% of the allocations during cairo-perf (e.g. 426,158 allocs out
of a total of 7,063,469).
It is possible for a scaled_font to be flagged as in error, though only
through a "true error" e.g. a malloc failure. However, when returning a font
from the cache it should not be in error. So if we find a error font in the
cache we remove it and return a new font.
These are all to satisfy new warnings caused by the preceding commit,
(which added cairo_warn to various function tables). While fixing the
propoagation, fix functions to declare a return type of cairo_status_t
instead of int.
The attribute was introduced with gcc-3.4, but the ability to suppress
warnings from misapplied attributes (-Wno-attributes) was only introduced
later. Without the supression, gcc will emit tens of warnings for each
compilation completely drowning the real errors that the programmer
must see.
The function calls that get the new treatment here are:
_cairo_meta_surface_replay
_cairo_surface_show_page
_cairo_array_append
all within _cairo_svg_surface_emit_meta_surface
Also fix all callers to notice and propagate the error, (though
some paths will still lose the CAIRO_STATUS_INVALID_MATRIX value
due to a return value of NULL at one point).
Fixing this uncovered a leak of a CAIRO_INT_STATUS_UNSUPPORTED value
up to cairo_show_page, (and similarly to cairo_copy_page). There was
really no good reason for _cairo_surface_show_page and
_cairo_surface_copy_page to be returning cairo_int_status_t. Fix
this by simply handling the UNSUPPORTED return at the surface layer
instead of the gstate layer.
Obviously, the new name is _cairo_pdf_surface_emit_to_unicode_stream which
is consistent with the to_unicode_stream identifiers already existing in
the implementation.
This class of functions modify their argument and return it as a
*convenience* for the caller. For example, within cairo a common idiom is:
cairo_object_reference (new);
cairo_object_unreference (this->obj);
this->obj = new;
which updates the member to the new object irrespective of whether the
new object is the same as the one being replaced. Other issues arise
with subtypes, as the return type is the parent's and so require more
complicated handling to compile cleanly.
Disabling the warning is therefore preferred over adding code which
decreases readibility and reduces maintainability. We need to make the
compiler work for us, not against us...
As previously implemented, there's no essential information in the
return value from _cairo_dotostr, (the caller can simply use strlen
to recompute the same value, which is what the only caller is already
doing).
There would be real information in a return value which would return
the result from the call to snprintf for the case where the buffer is
not large enough for the number being printed.
