1
0
mirror of https://git.FreeBSD.org/src.git synced 2024-12-06 09:17:25 +00:00
Mirror of the FreeBSD src repository https://git.FreeBSD.org/src.git .
Go to file
John Baldwin 53e1ffbbce The current POSIX semaphore implementation stores the _has_waiters flag
in a separate word from the _count.  This does not permit both items to
be updated atomically in a portable manner.  As a result, sem_post()
must always perform a system call to safely clear _has_waiters.

This change removes the _has_waiters field and instead uses the high bit
of _count as the _has_waiters flag.  A new umtx object type (_usem2) and
two new umtx operations are added (SEM_WAIT2 and SEM_WAKE2) to implement
these semantics.  The older operations are still supported under the
COMPAT_FREEBSD9/10 options.  The POSIX semaphore API in libc has
been updated to use the new implementation.  Note that the new
implementation is not compatible with the previous implementation.
However, this only affects static binaries (which cannot be helped by
symbol versioning).  Binaries using a dynamic libc will continue to work
fine.  SEM_MAGIC has been bumped so that mismatched binaries will error
rather than corrupting a shared semaphore.  In addition, a padding field
has been added to sem_t so that it remains the same size.

Differential Revision:	https://reviews.freebsd.org/D961
Reported by:	adrian
Reviewed by:	kib, jilles (earlier version)
Sponsored by:	Norse
2014-10-24 20:02:44 +00:00
bin sh: Allow backslash-newline continuation in more places: 2014-10-19 11:59:15 +00:00
cddl Correct the calculation of tcps_rto in the struct tcpcb -> tcpsinfo_t 2014-10-21 05:19:08 +00:00
contrib - Add sys/types.h for the APIs in sys/sysctl.h 2014-10-24 16:18:16 +00:00
crypto Merge OpenSSL 1.0.1j. 2014-10-15 19:12:05 +00:00
etc Hook libxo to the build. 2014-10-23 23:14:23 +00:00
games Update factor for changes to types in primes, which is a dependency. 2014-09-27 10:57:34 +00:00
gnu Build gperf only if we're using g++ (not clang++) 2014-10-09 23:05:31 +00:00
include The current POSIX semaphore implementation stores the _has_waiters flag 2014-10-24 20:02:44 +00:00
kerberos5 Fix incremental builds involving non-root users with read-only source files. 2014-09-18 14:50:21 +00:00
lib The current POSIX semaphore implementation stores the _has_waiters flag 2014-10-24 20:02:44 +00:00
libexec Add an "empty" Makefile.pc98 because it doesn't need/want HYPERV. It 2014-10-16 14:08:59 +00:00
release Add more descriptive metadata to the ISO images. 2014-10-17 03:55:33 +00:00
rescue Remove duplicate prog. 2014-09-28 08:59:38 +00:00
sbin Fix documentation issue. 2014-10-24 17:06:56 +00:00
secure Merge OpenSSL 1.0.1j. 2014-10-15 19:29:22 +00:00
share Add D-Link DWA-123 rev D1 and Elecom WDC-150SU2M. 2014-10-24 15:36:30 +00:00
sys The current POSIX semaphore implementation stores the _has_waiters flag 2014-10-24 20:02:44 +00:00
tests Fix source address selection on unbound sockets in the presence of multiple 2014-09-16 15:28:19 +00:00
tools Fix typo in src option description 2014-10-21 20:44:33 +00:00
usr.bin The current POSIX semaphore implementation stores the _has_waiters flag 2014-10-24 20:02:44 +00:00
usr.sbin Improve ctld.conf example. 2014-10-24 12:30:43 +00:00
.arcconfig Update the URL to the phabricator instance. 2014-08-14 16:25:43 +00:00
.arclint arc: add linting for python files 2014-06-02 00:21:42 +00:00
COPYRIGHT
LOCKS
MAINTAINERS add myself as opencrypto maintainer as I'm doing some work in the 2014-08-11 19:03:20 +00:00
Makefile Import OpenSSL 1.0.1j. 2014-10-15 17:32:57 +00:00
Makefile.inc1 My previous commit exposed an issue as it fixed a different 2014-10-22 03:39:11 +00:00
ObsoleteFiles.inc - Honer MK_KERBEROS for Heimdal rc.d scripts. 2014-10-19 20:46:59 +00:00
README Import OpenSSL 1.0.1j. 2014-10-15 17:32:57 +00:00
UPDATING Build gperf only if we're using g++ (not clang++) 2014-10-09 23:05:31 +00:00

This is the top level of the FreeBSD source directory.  This file
was last revised on:
$FreeBSD$

For copyright information, please see the file COPYRIGHT in this
directory (additional copyright information also exists for some
sources in this tree - please see the specific source directories for
more information).

The Makefile in this directory supports a number of targets for
building components (or all) of the FreeBSD source tree, the most
commonly used one being ``world'', which rebuilds and installs
everything in the FreeBSD system from the source tree except the
kernel, the kernel-modules and the contents of /etc.  The ``world''
target should only be used in cases where the source tree has not
changed from the currently running version.  See:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html
for more information, including setting make(1) variables.

The ``buildkernel'' and ``installkernel'' targets build and install
the kernel and the modules (see below).  Please see the top of
the Makefile in this directory for more information on the
standard build targets and compile-time flags.

Building a kernel is a somewhat more involved process, documentation
for which can be found at:
   http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html
And in the config(8) man page.
Note: If you want to build and install the kernel with the
``buildkernel'' and ``installkernel'' targets, you might need to build
world before.  More information is available in the handbook.

The sample kernel configuration files reside in the sys/<arch>/conf
sub-directory (assuming that you've installed the kernel sources), the
file named GENERIC being the one used to build your initial installation
kernel.  The file NOTES contains entries and documentation for all possible
devices, not just those commonly used.  It is the successor of the ancient
LINT file, but in contrast to LINT, it is not buildable as a kernel but a
pure reference and documentation file.


Source Roadmap:
---------------
bin		System/user commands.

cddl		Various commands and libraries under the Common Development
		and Distribution License.

contrib		Packages contributed by 3rd parties.

crypto		Cryptography stuff (see crypto/README).

etc		Template files for /etc.

games		Amusements.

gnu		Various commands and libraries under the GNU Public License.
		Please see gnu/COPYING* for more information.

include		System include files.

kerberos5	Kerberos5 (Heimdal) package.

lib		System libraries.

libexec		System daemons.

release		Release building Makefile & associated tools.

rescue		Build system for statically linked /rescue utilities.

sbin		System commands.

secure		Cryptographic libraries and commands.

share		Shared resources.

sys		Kernel sources.

tools		Utilities for regression testing and miscellaneous tasks.

usr.bin		User commands.

usr.sbin	System administration commands.


For information on synchronizing your source tree with one or more of
the FreeBSD Project's development branches, please see:

  http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html