Guys, if we the following on FreeBSD (pseudo-code):
fd = open(/dev/dsp, O_RDWR); mmap(PROT_READ, fd); mmap(PROT_WRITE, fd); This won't work entirely correctly, right? I base my question on some observations of how a particular program behaves on FreeBSD and on the following comment in sys/dev/sound/pcm/dsp.c: /* * XXX The linux api uses the nprot to select read/write buffer * our vm system doesn't allow this, so force write buffer. * * This is just a quack to fool full-duplex mmap, so that at * least playback _or_ recording works. If you really got the * urge to make _both_ work at the same time, avoid O_RDWR. * Just open each direction separately and mmap() it. * * Failure is not an option due to INVARIANTS check within * device_pager.c, which means, we have to give up one over * another. */ P.S. is this something that can easily fixed or not? -- Andriy Gapon _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
