The standard states in section 19.5.93:
.... Notice that if this operation is performed
on an obeject reference such as one produced by
the Alias, Index, or RefOf statements, the obect
type of the base object is returned.
Do the debuglevel check before calling the print
function for _threaddebug, by making it a macro.
Do not waste cycles passing arguments.
Generalize the _threaddebug function into _threadprint()
and add a varargcheck pragma. This function can
also be used from _threadassert().
Fix missing arguments in one case, fix trailing
newlines in _threaddebug().
Make _threadgetproc()/_threadsetproc() a macro,
just dereferencing Proc**_threadprocp.
Simplify the mainjump, just call _threadsetproc()
directly without that mainp dance. Remove the
_schedinit() argument, it uses _threadgetproc() now.
Get rid of Mainarg struct, just have a global variable
for argc.
The timing loop is here for the case if the
controller doesnt produce an interrupt when
becoming broken. In normal case, we should
just get worken up from the interrupt.
In any case, 100 times a second polling is
not neccessary here, increase to 1 second.
The old strategy of wait and retry doesnt seem to
work very well as it keeps all the forking parents
stuck waiting in the kernel worsening the situation.
The idea with this change is to have rfork() return
error quickly; and without whining; as most callers
would just react with a sysfatal() which might be
better for surviving this.
It is a bit of a annoyance that kenc will try to expand
function like macros on any symbol with the same name
and then complain when it doesnt see the '(' in the
invocation.
test case below:
void
foo(int)
{
}
struct Bar
{
int baz; /* <- should not conflict */
};
void
main(void)
{
baz(123);
}
The current behaviour of the kernel to deadlock itself
instead of returning an error on fork.
This might change in the future, so prepare libthread
to handle this case.
For _schedfork(), we'r going to just retry forking
on every switch, while for _schedexec(), the exec
will fail and send ~0 down the pid channel.
The ipoput4() and ipoput6() functions can raise an error(),
which means before calling sndrst() or limbo() (from tcpiput()),
we have to get rid of our blist by calling freeblist(bp).
Makse sure to set the Block pointer to nil after freeing in
ipiput() to avoid accidents.
Fix wrong panic string in sndsynack, and make any sending
functions like sndrst(), sndsynack() and tcpsendka()
return the value of ipoput*(), so we can distinguish
"no route" error.
Add a Enoroute[] string constant.
Both htontcp4() and htontcp6() can never return nil,
as they will allocate new or resize the existing block.
Remove the misleading error handling code that assumes
that it can fail.
Unlock proto on error in limborexmit() which can
be raised from sndsynack() -> ipoput*() -> error().
Make sndsynack() pass a Routehint pointer to ipoput*()
as it already did the route lookup, so we dont have todo
it twice.
i'm not confident about mutating the route tree
pointers and have concurrent readers walking the
pointer chains.
given that most route lookups are bypassed now
for non-routing case and we are not building a
high performance router here, lets play it safe.
theres no structure in the lower 32 bits of an ipv6 address.
use the top bit to distinguish special stuff like multicast
and link-local addresses, and use the 16-bit subnet-id bits
for the rest.
Instead of having to do an arp hash table lookup for each
outgoing ip packet, forward the Routehint pointer to the
medium's bwrite() function and let it cache the arp entry
pointer.
This avoids route and arp hash table lookups for tcp, il
and connection oriented udp.
It also allows us to avoid multiple route and arp table
lookups for the retransmits once an arp/neighbour solicitation
response arrives.
The Mhead structures have two sources of references to them:
- from Pgrp.mnthash hash-table
- from a channels Chan.umh pointer as returned by namec() for a union directory
Unless one holds the Mhead.lock RWLock, the Mhead.mount chain
can be mutated by eigther cmount(), cunmount() or closepgrp().
Readers, skipping acquiering the lock where:
mountfix(): responsible for rewriting directory entries for
union directory reads; was walking the Mhead.mount chain to
detect if the passed channel itself appears in the mount list.
cmount(): had a check and copy when "new" chan was a union itself
and if the MCREATE flag is set and would copy the mount table.
All this needs to be done with Mhead read-locked while copying
the mount entries.
devproc(): in the handler for reading /proc/n/ns file.
namec(): while checking if the Chan->umh should be initialized.
In addition to this, cmount() is changed to do the mountfree()
of the original mount chain when MREPL is done after releasing
the locks.
Also, some cosmetic changes...
The IPv4 ARP cache used to indefinitely buffer packets in the Arpent hold list.
This is bad in case of a router, because it opens a 1 second
(retransmit time) window to leak all the to be forwarded packets.
This change makes the ipv4 arp code path similar to the IPv6 neighbour
solicitation path, using the retransmit process to time out old entries
(after 3 arp retransmits => 3 seconds).
A new function arpcontinue() has been added that unifies the point when
we schedule the (ipv6 sol retransmit) / (ipv4 arp timeout) and reduce
the hold queue to the last packet and unlock the cache.
As a bonus, we also now send a icmp host unreachable notification
for the dropped packets.
tlsbwrite() would call checkstate() before calling tlsrecwrite()
to make sure the channel is open. however, because checkstate()
only raises the error, the Block* passed wont be freed and
would result in a memory leak.
move the checkstate() call inside tlsrecwrite() to reuse the
error handling that frees the block on error.
in OpenBSD 6.9 and up, the kernel (bsd, bsd.mp) still has
the ostype symbols, but bsd.rd appears to have lost them,
even when decompressed.
so, as a result, we should use what we have, which isn't
much.
Due to the way LCA is defined, a using a strict LCA
on a graph like this:
<--a--b--c--d--e--f--g
\ /
+-----h-------
can lead to spurious requests to merge. This happens
because 'lca(b, g)' would return 'a', since it can be
reached in one step from 'b', and 2 steps from 'g', while
reaching 'b' from 'a' would be a longer path.
As a result, we need to implement an lca variant that
returns the starting node if one is reachable from the
other, even if it's already found the technically correct
least common ancestor.
This replaces our LCA algorithm with one based on the
painting we do while finding a twixt, making it give
the resutls we want.
git/query: fix spurious merge requests
Due to the way LCA is defined, a using a strict LCA
on a graph like this:
<--a--b--c--d--e--f--g
\ /
+-----h-------
can lead to spurious requests to merge. This happens
because 'lca(b, g)' would return 'a', since it can be
reached in one step from 'b', and 2 steps from 'g', while
reaching 'b' from 'a' would be a longer path.
As a result, we need to implement an lca variant that
returns the starting node if one is reachable from the
other, even if it's already found the technically correct
least common ancestor.
This replaces our LCA algorithm with one based on the
painting we do while finding a twixt.
directory entries cannot span sector boundaries, meaning
that the end of a sector would be zero padded until the
next sector.
we have to skip over these zero paddings to fully read
the directory.
Plumber both posts a service to /srv and sets a $plumbsrv environment
variable. Our libplumb no longer uses $plumbsrv and nothing else
does. It's a silly hack; rc doesn't update /env immediately, and
scripts, which for instance set up subrios, cannot rely on it to
clean up the plumber at the end.
Instead, add the option to specify a srvname, actually check for some
common errors and print a usage string.
Thanks to Ori for input and a preliminary patch.
