[Rd] memory leak in png()

[Duncan Murdoch]

I don't have a valgrind-capable version of R, but I'd be interested to 
see whether this is a one-time loss, or repeated.  That is, do you get a 
much bigger loss from running the lossy code in a loop like this?

  for (i in 1:100) { png(filename='p.png'); plot(1:10); dev.off() }

Duncan Murdoch


On 17/01/2023 4:55 a.m., Martin Maechler wrote:
>>>>>> Edward Ionides
>>>>>>      on Mon, 16 Jan 2023 09:04:49 -0500 writes:
> 
>      > Hi all,
> 
>      > Yesterday I discovered what seems to me like a memory leak in png() so I'm
>      > reporting it in case that is helpful. Here is a small reproducible example:
> 
>      > R -d "valgrind --tool=memcheck --track-origins=yes --leak-check=full"
>      > --vanilla -e "png(filename='p.png'); plot(1:10); dev.off()"
>      > ## HAS LEAK
>      > ==1021711== LEAK SUMMARY:
>      > ==1021711==    definitely lost: 9,216 bytes in 30 blocks
>      > ==1021711==    indirectly lost: 19,370 bytes in 838 blocks
>      > ==1021711==      possibly lost: 3,868 bytes in 8 blocks
> 
>      > R -d "valgrind --tool=memcheck --track-origins=yes --leak-check=full"
>      > --vanilla -e "pdf(file='p.pdf'); plot(1:10); dev.off()"
>      > ## NO LEAK
>      > ==1031300== LEAK SUMMARY:
>      > ==1031300==    definitely lost: 0 bytes in 0 blocks
>      > ==1031300==    indirectly lost: 0 bytes in 0 blocks
>      > ==1031300==      possibly lost: 0 bytes in 0 blocks
> 
> I can reproduce, although I need to have the memcheck options in ~/.valgrindrc
> The same happens if grid-based graphics is used and for the
> latest R-devel :
> 
> R-devel -d valgrind --vanilla -e 'png("p.png");lattice::xyplot(1~1);dev.off()'
> 
> Using  png() shows leak
> using  pdf()  is fine (0 bytes lost)
> 
> 
> Looking at the full report (--leak-check=full  --track-origins=true
> as 2 lines in ~/.valgrindrc ) I see several origins tracked to
> internal malloc code,
> but then also e.g.,
> 
> ==1410108== 96 bytes in 1 blocks are possibly lost in loss record 700 of 3,037
> ==1410108==    at 0x484A464: calloc (vg_replace_malloc.c:1328)
> ==1410108==    by 0x159EA3A0: g_malloc0 (gmem.c:155)
> ==1410108==    by 0x15A3AB8C: g_rc_box_alloc_full.constprop.0 (grcbox.c:234)
> ==1410108==    by 0x1600A6C9: UnknownInlinedFun (pangofc-fontmap.c:899)
> ==1410108==    by 0x1600A6C9: UnknownInlinedFun (pangofc-fontmap.c:2145)
> ==1410108==    by 0x1600A6C9: pango_fc_font_map_load_fontset (pangofc-fontmap.c:2245)
> ==1410108==    by 0x158E7474: UnknownInlinedFun (itemize.c:892)
> ==1410108==    by 0x158E7474: UnknownInlinedFun (itemize.c:952)
> ==1410108==    by 0x158E7474: pango_itemize_with_font (itemize.c:1564)
> ==1410108==    by 0x158FA89E: pango_layout_check_lines.part.0.lto_priv.0 (pango-layout.c:4894)
> ==1410108==    by 0x158EF4DB: UnknownInlinedFun (pango-layout.c:4786)
> ==1410108==    by 0x158EF4DB: pango_layout_get_line (pango-layout.c:1715)
> ==1410108==    by 0x1B5E441F: PG_text_extents (cairoFns.c:1487)
> ==1410108==    by 0x1B5E441F: PangoCairo_StrWidth (cairoFns.c:1565)
> ==1410108==    by 0x4CEBE6: GEStrWidth (engine.c:2615)
> ==1410108==    by 0x4CEBE6: GEStrWidth (engine.c:2578)
> ==1410108==    by 0x1BE12D11: textRect (util.c:198)
> ==1410108==    by 0x1BDFAF19: gridText (grid.c:3740)
> ==1410108==    by 0x1BE01FAB: L_textBounds (grid.c:3892)
> 
> which (from the bottom up) shows  package grid C code,
> then R main but infrastructure for grDevices ("GEStrWidth (engine.c)")  and
> subdirectory grDevices/src/cairo/cairoFns.c
> and then goes into system cairo or pangocairo libraries,
> which here (Linux Fedora 36) are (I thik)
> 
> 	libpangocairo-1.0.so.0
> 	libpango-1.0.so.0
> 
> {as they are stripped, I don't know how to check }
> 
> To *fix* this I also have to defer to others.
> 
> Thank you for the report,
> Martin
> 
> --
> Martin Maechler
> ETH Zurich  and  R Core team
> 
> 
>      > For some context, I am running R4.2.2. My goal was to run valgrind on the
>      > latest version of my spatPomp package. A memory leak was detected by
>      > rhub::check_with_valgrind(). I then tracked down the problem by running
>      > valgrind locally and in the end it seemed to come down to a problem with
>      > png(). This was used in the spatPomp unit tests while testing the plot
>      > method. I can use pdf() instead, but the point here is to report the issue
>      > in case it is not known.
> 
>      > I'm new to R package development and happy to accept any advice.
> 
>      > Thanks,
>      > Ed
> 
>      > Edward L. Ionides
>      > Associate Chair for Undergraduate Studies and Professor,
>      > Department of Statistics, University of Michigan
>      > 1085 South University, Ann Arbor, MI 48109-1107
>      > email: ionides using umich.edu
>      > phone: 734 615 3332
>      > office: 453 West Hall
> 
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> 
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