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d585939e08
Replace 4.4BSD Lite's unix domain socket backpressure hack with a cleaner
mechanism, based on the new SB_STOP sockbuf flag. The old hack dynamically
changed the sending sockbuf's high water mark whenever adding or removing
data from the receiving sockbuf. It worked for stream sockets, but it never
worked for SOCK_SEQPACKET sockets because of their atomic nature. If the
sockbuf was partially full, it might return EMSGSIZE instead of blocking.
The new solution is based on DragonFlyBSD's fix from commit
3a6117bbe0ed6a87605c1e43e12a1438d8844380 on 2008-05-27. It adds an SB_STOP
flag to sockbufs. Whenever uipc_send surpasses the socket's size limit, it
sets SB_STOP on the sending sockbuf. sbspace() will then return 0 for that
sockbuf, causing sosend_generic and friends to block. uipc_rcvd will
likewise clear SB_STOP. There are two fringe benefits: uipc_{send,rcvd} no
longer need to call chgsbsize() on every send and receive because they don't
change the sockbuf's high water mark. Also, uipc_sense no longer needs to
acquire the UIPC linkage lock, because it's simpler to compute the
st_blksizes.
There is one drawback: since sbspace() will only ever return 0 or the
maximum, sosend_generic will allow the sockbuf to exceed its nominal maximum
size by at most one packet of size less than the max. I don't think that's
a serious problem. In fact, I'm not even positive that FreeBSD guarantees a
socket will always stay within its nominal size limit.
sys/sys/sockbuf.h
Add the SB_STOP flag and adjust sbspace()
sys/sys/unpcb.h
Delete the obsolete unp_cc and unp_mbcnt fields from struct unpcb.
sys/kern/uipc_usrreq.c
Adjust uipc_rcvd, uipc_send, and uipc_sense to use the SB_STOP
backpressure mechanism. Removing obsolete unpcb fields from
db_show_unpcb.
tests/sys/kern/unix_seqpacket_test.c
Clear expected failures from ATF.
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| Kyuafile | ||
| Makefile | ||
| README | ||
src/tests: The FreeBSD test suite
=================================
This file describes the build infrastructure of the FreeBSD test suite.
If you are only interested in using the test suite itself, please refer
to tests(7) instead.
The build of the test suite is organized in the following manner:
* The build of all test artifacts is protected by the MK_TESTS knob.
The user can disable these with the WITHOUT_TESTS setting in
src.conf(5).
* The goal for /usr/tests/ (the installed test programs) is to follow
the same hierarchy as /usr/src/ wherever possible, which in turn drives
several of the design decisions described below. This simplifies the
discoverability of tests. We want a mapping such as:
/usr/src/bin/cp/ -> /usr/tests/bin/cp/
/usr/src/lib/libc/ -> /usr/tests/lib/libc/
/usr/src/usr.bin/cut/ -> /usr/tests/usr.bin/cut/
... and many more ...
* Test programs for specific utilities and libraries are located next
to the source code of such programs. For example, the tests for the
src/lib/libcrypt/ library live in src/lib/libcrypt/tests/. The tests/
subdirectory is optional and should, in general, be avoided.
* The src/tests/ hierarchy (this directory) provides generic test
infrastructure and glue code to join all test programs together into
a single test suite definition.
* The src/tests/ hierarchy also includes cross-functional test programs:
i.e. test programs that cover more than a single utility or library
and thus don't fit anywhere else in the tree. Consider this to follow
the same rationale as src/share/man/: this directory contains generic
manual pages while the manual pages that are specific to individual
tools or libraries live next to the source code.
In order to keep the src/tests/ hierarchy decoupled from the actual test
programs being installed --which is a worthy goal because it simplifies
the addition of new test programs and simplifies the maintenance of the
tree-- the top-level Kyuafile does not know which subdirectories may
exist upfront. Instead, such Kyuafile automatically detects, at
run-time, which */Kyuafile files exist and uses those directly.
Similarly, every directory in src/ that wants to install a Kyuafile to
just recurse into other subdirectories reuses this Kyuafile with
auto-discovery features. As an example, take a look at src/lib/tests/
whose sole purpose is to install a Kyuafile into /usr/tests/lib/.
The goal in this specific case is for /usr/tests/lib/ to be generated
entirely from src/lib/.
--
$FreeBSD$