Secure promiscuous mode

jack_wait: return exit code failure on timeout

Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>

Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>

Fixes #288

Thanks to Timo Wischer for the initial work

Be more verbose about $JACK_NO_AUDIO_RESERVATION

Fix gcc7 build and JackDebugClient

Fix mingw compilation

Fix some issues on Windows.

Added -S option and supporting code to permit attaching to a named jack2 server.

Adjusts the permissions of posix semaphores when promiscuous mode is enabled.

Note that changing permissions of semaphores is only supported on linux by
using the /dev/shm filesystem. As of now, linux does not use posix semaphores
anymore so this code is currently unsed.

Adjusts the permissions of linux futexes when promiscuous mode is enabled.

Adjusts the permissions of unix sockets when promiscuous mode is enabled.

Adjusts the permissions of shared memory segments when promiscuous mode is
enabled.

The jack_group2gid() function does a thread-safe lookup of a unix gid from a
unix group name.

The jack_promiscuous_perms() function adjusts the permissions of a shared
resource (socket, semaphore, shm segment, ...) referenced by a fd and/or a
path so it can be used by any member of the provided unix group.

By using those functions it will be possible to enable a secure promiscuous
mode. 'Secure' meaning here that one is not forced to launch every clients
with a (way) too permissive 0000 umask.

Correct typos in JackNetTool.cpp

Account for IP+UDP header in MTU

alsa_in/out: Convert between sample rates when necessary

alsa_in and alsa_out set the playback latency of their ports to the target delay. The problem is the target delay is in terms of the ALSA sample rate, so it should be converted to JACK's sample rate.

Example: Imagine JACK is running at 48 kHz, and alsa_out is invoked like:

alsa_out -r 96000 -t 512
Currently, alsa_out will report 512 frames of playback latency. After the fix, it converts to 48kHz and correctly reports 256.

Also converts the result of jack_frames_since_cycle_start to ALSA sample rate.

Use linux futex as JackSynchro

Valgrind

Add autoclose option to jack_load

tests: define __STDC_LIMIT_MACROS

Fix crash in JackPosixSemaphore::Wait

Includes optimizations for internal clients, but not enabled yet.

This doesn't seem necessary since it is implmented below

Crash was observed in this function when fSemaphore was NULL, this patch
copies the NULL pointer check from the commented function above into
Wait()

Waf macosx fixes

ARM Neon support for non-dithering sample conversion functions

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>