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<p class="MsoNormal"><span lang="EN-US">Hi <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Assertion: cairo-1.15.2/src/cairo-scaled-font.c:1317: cairo_scaled_font_destroy: Assertion `! scaled_font->cache_frozen' failed.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">This happens in calling cairo_glyph_extents when several threads work on scaled_font.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Cairo_scaled_font_destroy is obviously unsafe for multithread, so the assertion may be triggered occasionally.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">In my situation, following patch can solve my trouble<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">------------------------ cairo/src/cairo-scaled-font.c ------------------------<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">index ac80c97..bea10f4 100644<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">@@ -1314,6 +1314,8 @@ cairo_scaled_font_destroy (cairo_scaled_font_t *scaled_font)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> if (! _cairo_reference_count_dec_and_test (&scaled_font->ref_count))<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> return;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#70AD47">+ CAIRO_MUTEX_LOCK(scaled_font->mutex);<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#70AD47">+ <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> assert (! scaled_font->cache_frozen);<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> assert (! scaled_font->global_cache_frozen);<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">@@ -1357,7 +1359,7 @@ cairo_scaled_font_destroy (cairo_scaled_font_t *scaled_font)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> unlock:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> _cairo_scaled_font_map_unlock ();<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">-<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#70AD47">+ CAIRO_MUTEX_UNLOCK(scaled_font->mutex);
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> /* If we pulled an item from the holdovers array, (while the font<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> * map lock was held, of course), then there is no way that anyone<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> * else could have acquired a reference to it. So we can now<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">So will cairo_scaled_font_destroy be optimized in further release?
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">BR</span><span lang="EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Bin Wu<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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