<html xmlns:o=3D"urn:schemas-microsoft-com:office:office" xmlns:w=3D"urn:sc= hemas-microsoft-com:office:word" xmlns:m=3D"http://schemas.microsoft.com/of= fice/2004/12/omml" xmlns=3D"http://www.w3.org/TR/REC-html40%22%3E<head><meta ht= tp-equiv=3DContent-Type content=3D"text/html; charset=3Dutf-8"><meta name= =3DGenerator content=3D"Microsoft Word 15 (filtered medium)"><style><!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {margin:0cm; margin-bottom:.0001pt; font-size:11.0pt; font-family:"Calibri",sans-serif;} a:link, span.MsoHyperlink {mso-style-priority:99; color:blue; text-decoration:underline;} .MsoChpDefault {mso-style-type:export-only;} @page WordSection1 {size:612.0pt 792.0pt; margin:72.0pt 72.0pt 72.0pt 72.0pt;} div.WordSection1 {page:WordSection1;} --></style></head><body lang=3DEN-CA link=3Dblue vlink=3D"#954F72"><div cla= ss=3DWordSection1><p class=3DMsoNormal>Sorry, I should have added a little = more detail. Specifically, I was seeing the `pos` variable in `mdb_page_flu= sh` going over 2^31, and this being manifested in failed shift right here (= resulting in 2^32 -1):<o:p></o:p></p><p class=3DMsoNormal><a href=3D"https:= //github.com/LMDB/lmdb/blob/mdb.master/libraries/liblmdb/mdb.c#L3711">https= ://github.com/LMDB/lmdb/blob/mdb.master/libraries/liblmdb/mdb.c#L3711</a> <= /p><p class=3DMsoNormal><o:p> </o:p></p><p class=3DMsoNormal>Thanks,<b= r>Kris</p><p class=3DMsoNormal><o:p> </o:p></p><div style=3D'mso-eleme= nt:para-border-div;border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt= 0cm 0cm 0cm'><p class=3DMsoNormal style=3D'border:none;padding:0cm'><b>Fro= m: </b><a href=3D"mailto:hyc@symas.com">Howard Chu</a><br><b>Sent: </b>Febr= uary 20, 2020 9:08 PM<br><b>To: </b><a href=3D"mailto:kriszyp@gmail.com">kr= iszyp@gmail.com</a><br><b>Cc: </b><a href=3D"mailto:openldap-its@openldap.o= rg">openldap-its@OpenLDAP.org</a><br><b>Subject: </b>Re: (ITS#9017) Improvi= ng performance of commit sync in Windows</p></div><p class=3DMsoNormal><o:p=
</o:p></p><p class=3DMsoNormal>Howard Chu wrote:</p><p class=3DMsoNo=
rmal>> There should be an off64_t type instead.</p><p class=3DMsoNormal>= <o:p> </o:p></p><p class=3DMsoNormal><o:p> </o:p></p><p class=3DM= soNormal>> But it looks to me like only the env->me_size field could = ever overflow,</p><p class=3DMsoNormal>> and using size_t for that shoul= d be fine. The other uses are for the meta page, which is always either off= set 0 or</p><p class=3DMsoNormal>> offset 4096 (with 4KB pagesize), and = the lockfile, which is always smaller than 2GB.</p><p class=3DMsoNormal><o:= p> </o:p></p><p class=3DMsoNormal>Ignore that, I was looking at the 0.= 9 branch when I wrote that.</p><p class=3DMsoNormal><o:p> </o:p></p><p= class=3DMsoNormal>-- </p><p class=3DMsoNormal>=C2=A0=C2=A0-- Howard Chu</p=
<p class=3DMsoNormal>=C2=A0 CTO, Symas Corp.=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 http://www.symas.com</p><p class=3DMsoNormal=
=C2=A0 Director, Highland Sun=C2=A0=C2=A0=C2=A0=C2=A0 http://highlandsun.c=
om/hyc/</p><p class=3DMsoNormal>=C2=A0 Chief Architect, OpenLDAP=C2=A0 http= ://www.openldap.org/project/</p><p class=3DMsoNormal><o:p> </o:p></p><= /div></body></html>=
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