between creation of a file descriptor and close(2) when using kernel
assisted threads. What we do is stick descriptors in the table, but
mark them as "larval". This causes essentially everything to treat
it as a non-existent descriptor, except for fdalloc(), which sees a
filled slot so that it won't (incorrectly) allocate it again. When
a descriptor is fully constructed, the code that has constructed it
marks it as "mature" (which actually clears the "larval" flag), and
things continue to work as normal.
While here, gather all the code that gets a descriptor from the table
into a fd_getfile() function, and call it, rather than having the
same (sometimes incorrect) code copied all over the place.
The optimized integer formula was supplied by Wolfgang Solfrank on
"tech-kern@netbsd.org". This fixes problems with e.g FreeBSD TV (fxtv),
RealPlayer-7.0 Beta 2 (PR pkg/10818) and KDE's "kscd".
encodings, too. (This is currently an issue with the eso(4) driver, which,
due to different byte orders in playing and recording directions, sets the
emulated flag for all 16-bit encodings, although it could be argued that this
is an unfortunate weakness of the query_encoding() interface.)
count is 0, wait for use count to drain before finishing the close.
This is necessary in order for multiple processes to safely share file
descriptor tables.
the /dev/rmidiN devices, or with a sequencer interface via /dev/music.
So far the only supported MIDI device is the MPU401 port on SoundBlaster
(and only on SB on isapnp, since we do not have locators with multiple
values yet).
The changes is to allow some limited mixer manipulation through
the audio device (instead of the mixer device).
This rendered 4 methods in audio_hw_if unused so garbage collect these.
- It is now possible to handle devices that want "looping" DMA,
e.g. the SoundBlaster correctly. The WSS and SB drivers use this.
To do this several new methods were introduced in audio_hw_if.
- Different silence handling (forced by previous change).
- The audio driver can now be mmap()-ed, but due to problems in
the VM system only for writing for now.
- The OSS (Linux) audio emulation takes advantage of some of the
new features.
renamed AUDIO_ENCODING_SLINEAR and AUDIO_ENCODING_LINEAR reverts to the
NetBSD 1.2 sematics. A kernel with COMPAT_12 defined will accept
AUDIO_ENCODING_LINEAR and treat it as before, without COMPAT_12 it
will be rejected.
mycroft