Date: Thu, 18 May 2000 11:55:09 -0400 From: Joy Ganguly <joy@niksun.com> To: freebsd-hackers <freebsd-hackers@freeBSD.org> Subject: Re: Question about file write???? Message-ID: <3924125D.20A907D@falcon.niksun.com> References: <20000517160746.12768.qmail@www0a.netaddress.usa.net> <20000517102516.B14968@fw.wintelcom.net> <3922DB0F.9D9095C9@falcon.niksun.com> <20000517135644.D14968@fw.wintelcom.net> <39231E06.31DFB153@falcon.niksun.com> <200005172324.QAA28046@apollo.backplane.com>
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Matthew Dillon wrote: > > I think it would be a whole lot easier to implement mmap() on the > device, then allow the user process to mmap() the device buffer > and read() and write() it directly. I don't think you need to > implement any ioctl's for this problem. > > fd = open device > ptr = mmap(...) > > fd = open file > read(fd, ptr, BUFSIZE) read from file, store into device buf > ... > write(fd, ptr, BUFSIZE) read from device buf, store into file > > I am sorry that i missed this point in my previous post. well the problem with the mmap is that my device does not have a buffer always. earlier the 'read' ioctl on the device used to sleep till a buffer was available. what does the mmap do?? can it block?? i am sorry if this sounds naive bcoz i am a relative newbie thanx in advance -joy To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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