From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,7e32386ac8078f13 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news1.google.com!proxad.net!news.tele.dk!news.tele.dk!small.news.tele.dk!not-for-mail Sender: malo@0x535ddc7c.boanxx18.adsl-dhcp.tele.dk Newsgroups: comp.lang.ada Subject: Re: POSIX.Memory_Mapping.Map_Memory References: <1107014307.952357.216870@f14g2000cwb.googlegroups.com> <1107016260.265640.138990@z14g2000cwz.googlegroups.com> <1107053159.644479.173850@z14g2000cwz.googlegroups.com> <1107100953.572623.128530@f14g2000cwb.googlegroups.com> <87u0oykawh.fsf@deneb.enyo.de> <1109487570.008408.193130@f14g2000cwb.googlegroups.com> From: Mark Lorenzen Date: 27 Feb 2005 14:03:15 +0100 Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Organization: TDC Totalloesninger NNTP-Posting-Host: 83.93.220.124 X-Trace: 1109509395 dtext01.news.tele.dk 169 83.93.220.124:58880 X-Complaints-To: abuse@post.tele.dk Xref: g2news1.google.com comp.lang.ada:8507 Date: 2005-02-27T14:03:15+01:00 List-Id: "Adrian Hoe" writes: > Florian Weimer wrote: > > * Mark Lorenzen: > > > > >> I was just wondering: Is it allowed to map a device file as shared > > >> memory? Try to use MAP_PRIVATE instead of MAP_SHARED. > > > > > > Furthermore: I do not think that it is possible to map character > > > special files, since it only allows sequential access. You can > > > probably only map block special files. > > > > It's possible to map /dev/zero. In fact, there is little difference > > between character and block devices these days. > > > > Just for the purpose of recording for people who may need this in the > future: > > I've successfully mapped the memory with > POSIX.Memory_Mapping.Map_Memory. > > The VIDIOCGMBUF ioctl has to be issued before Map_Memory. This ioctl > reports the size of buffer to Memory_Map and the offset within the > buffer for each frame. > > My application is far from completion but I have resolved this > Memory_Map issue. I believe the wheel has just started rolling again. > :-) > > Regards, > > -- > Adrian Hoe Thanks for the info. So we can fortunately conclude that the problem is neither Ada nor Florist related, but is simply a special issue with this type of device. - Mark Lorenzen