Mac OS X

Mac OS X
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When trying to link multiple Berkeley DB language interfaces (for example, Tcl, C++, Java, Python) into a single process, I get "multiple definitions" errors from dyld.
To fix this problem, set the environment variable MACOSX_DEPLOYMENT_TARGET to 10.3 (or your current version of OS X), and reconfigure and rebuild Berkeley DB from scratch. See the OS X ld(1) and dyld(1) man pages for information about how OS X handles symbol namespaces, as well as undefined and multiply-defined symbols.

When trying to use system-backed shared memory on OS X I see failures about "too many open files".

The default number of shared memory segments on OS X is too low. To fix this problem, edit the file /etc/rc, changing the kern.sysv.shmmax and kern.sysv.shmseg values as follows:

*** /etc/rc.orig        Fri Dec 19 09:34:09 2003
--- /etc/rc     Fri Dec 19 09:33:53 2003
***************
*** 84,93 ****
   # System tuning
   sysctl -w kern.maxvnodes=$(echo $(sysctl -n hw.physmem) '33554432 /
512 * 1024 +p'|dc)
! sysctl -w kern.sysv.shmmax=4194304
   sysctl -w kern.sysv.shmmin=1
   sysctl -w kern.sysv.shmmni=32
! sysctl -w kern.sysv.shmseg=8
   sysctl -w kern.sysv.shmall=1024
   if [ -f /etc/sysctl-macosxserver.conf ]; then
         awk '{ if (!-1 && -1) print $1 }' < 
/etc/sysctl-macosxserver.conf | while read
--- 84,93 ----
   # System tuning
   sysctl -w kern.maxvnodes=$(echo $(sysctl -n hw.physmem) '33554432 /
512 * 1024 +p'|dc)
! sysctl -w kern.sysv.shmmax=134217728
   sysctl -w kern.sysv.shmmin=1
   sysctl -w kern.sysv.shmmni=32
! sysctl -w kern.sysv.shmseg=32
   sysctl -w kern.sysv.shmall=1024
   if [ -f /etc/sysctl-macosxserver.conf ]; then
         awk '{ if (!-1 && -1) print $1 }' <
 /etc/sysctl-macosxserver.conf | while read

and then reboot the system.

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