This is useful when you want to ensure some little thing happens when you
exit a certain scope.
This patch makes use of it in LibC's netdb code to make sure we close the
connection to the LookupServer.
LookupServer can now take two types of requests:
* L: Lookup
* R: Reverse lookup
The /bin/host program now does a reverse lookup if the input string is a
valid IPv4 address. :^)
If I'm understanding the standard C library correctly, setenv() copies while
putenv() does not. That's really confusing and putenv() basically sucks.
To know which environment variables to free on replacement and which ones to
leave alone, we keep track of the ones malloced by setenv in a side table.
This patch also moves Shell to using setenv() instead of putenv().
Fixes#29.
Right now, we allow anything inside a user to raise or lower any other process's
priority. This feels simple enough to me. Linux disallows raising, but
that's annoying in practice.
It can't be 100% precise but it doesn't really matter. Use this to implement
realloc() nicely. This also fixes a bug in realloc() where we didn't take
the size of the allocation metadata into account when computing the size of
an allocation backed by a BigAllocationBlock.
We were only reusing the existing allocation if the new requested size
was exactly the same as the fudged size of the block. This meant that
realloc() could allocate a new block even though the new block would be
identical to the old block.
Also run it across the whole tree to get everything using the One True Style.
We don't yet run this in an automated fashion as it's a little slow, but
there is a snippet to do so in makeall.sh.
Passing this flag to recv() temporarily puts the file descriptor into
non-blocking mode.
Also implement LocalSocket::recv() as a simple forwarding to read().
This is in keeping with how putenv should function. It does mean that
the shell's export command now leaks, but that's not a difficult fix.
Contributes to #29.
