On Sat, Feb 18, 2017, at 09:02 PM, Bart Schaefer wrote:
> You/we certainly may wish to document that it is dangerous to assume
> that parent and subshell can both manipulate the tied parameter, but
> it would be incorrect to automatically close the file descriptor in
> either of them.

I've updated docs and added "zgdbmclear" builtin as we now know GDBM is
fine with concurrent access if only it can be synchronized. In Zsh this
is possible via zsystem flock. I think PM_UPTODATE is a great feature as
no other program can change the database. With zsystem flock and
zgdbmclear, one can write a concurrent, elastic program within Zsh (a
challenge, though).

Also added a test case, but tests haven't been commited:

 ztie -d db/gdbm -f $dbfile dbase
 dbase[testkey]=value1
 fun() { while read line; do echo $line; done }
 eval "dbase[testkey]=value2" | fun
 echo $dbase[testkey]
 zgdbmclear dbase testkey
 echo $dbase[testkey]
0:Test store in forked Zsh
>value1
>value2

Best regards,
Sebastian Gniazdowski