use. If it is in use, use the watched request, otherwise use the
lockuser's own request. Only allocate a lockuser request if both
requests are null.
PR: 119920
Tested by (6.x): Landon Fuller <landonf -at- bikemonkey -dot- org>
This protects against a race with an upcall in the parent during the
fork which can clobber the parent's tcb before the vm space is copied
in the child. The child then gets a corrupted tcb that is either null
or that points to another thread that doesn't exist in the child (after
a fork, only the fork()ing thread exists in the child).
Reported by: Arno J. Klaassen (arno at heho / snv / jussieu / fr)
ia64, powerpc, and sparc64, use ANSI function headers and specifically
indicate the lack of arguments with 'void'. Otherwise, warnings are
generated at WARNS=3, leading to a compile failure with -Werror.
libkse in FreeBSD 8.0, do not build or install static versions of libkse
(i.e. libkse*.a) in the default case. Static versions will be built and
installed if libthr is not built or if libkse is the default threading
library.
Discussed on: freebsd-arch
MFC after: 3 days
doesn't use the default CFLAGS which contain -fno-strict-aliasing.
Until the code is cleaned up, just add -fno-strict-aliasing to the
CFLAGS of these for the tinderboxes' sake, allowing the rest of the
tree to have -Werror enabled again.
is also implemented in glibc and is used by a number of existing
applications (mysql, firefox, etc).
This mutex type is a default mutex with the additional property that
it spins briefly when attempting to acquire a contested lock, doing
trylock operations in userland before entering the kernel to block if
eventually unsuccessful.
The expectation is that applications requesting this mutex type know
that the mutex is likely to be only held for very brief periods, so it
is faster to spin in userland and probably succeed in acquiring the
mutex, than to enter the kernel and sleep, only to be woken up almost
immediately. This can help significantly in certain cases when
pthread mutexes are heavily contended and held for brief durations
(such as mysql).
Spin up to 200 times before entering the kernel, which represents only
a few us on modern CPUs. No performance degradation was observed with
this value and it is sufficient to avoid a large performance drop in
mysql performance in the heavily contended pthread mutex case.
The libkse implementation is a NOP.
Reviewed by: jeff
MFC after: 3 days
the threading libraries is built. This simplifies the
logic in makefiles that need to check if the pthreads
support is present. It also fixes a bug where we would
build a threading library that we shouldn't have built:
for example, building with WITHOUT_LIBTHR and the default
value of DEFAULT_THREADING_LIB (libthr) would mistakenly
build the libthr library, but not install it.
Approved by: re (kensmith)
Warning, after symbol versioning is enabled, going back is not easy
(use WITHOUT_SYMVER at your own risk).
Change the default thread library to libthr.
There most likely still needs to be a version bump for at least the
thread libraries. If necessary, this will happen later.
child thread goes back to system scope rather than process
scope. This allows an ensuing exec() to actually work.
This change was made a year ago here, but I "forgot" to
commit it :(
Approved by: deischen
MFC after: 3 weeks
they become candidates for reuse. Without this fix, some of the
state from a thread structure's previous incarnation could interfere
with its new one. Specifically, a non-bound thread started as
"suspended" (see pthread_attr_setcreatesuspend_np()) might not get
scheduled at all when resumed, as the "active" flag would be set
spuriously.
Reviewed by: deischen@, davidxu@
MFC after: 1 week
is also returned by pthread_detach() if a thread was already
detached, the error code was already documented:
> [EINVAL] The implementation has detected that the value speci-
> fied by thread does not refer to a joinable thread.
o avoid using a global register variable.
o redefine struct ia64_tp as a union. We don't have to get to the
fields themselves. We just need it to be of the right size with
the right alignment.
16-byte aligned. Consequently, struct tcb is a multiple of 16
bytes in size. We need to make sure there's no padding after
struct ppc32_tp. We do this by explicitly adding the necessary
padding in front of it.
do its work for SIGINFO. Always install libpthread signal handler
wrapper for SIGINFO even if user SIG_IGN's or SIG_DFL's it.
SIGINFO has a special meaning for libpthread: when LIBPTHREAD_DEBUG
enviroment variable defined it is used for dumping an information
about threads to /tmp/.
Reported by: mi
Reviewed by: deischen
MFC after: 2 weeks
used LIBTHREAD_1_0 as its version definition, but now needs
to define its symbols in the same namespace used by libc.
The compatibility hooks allows you to use libraries and
binaries built and linked to libpthread before libc was
built with symbol versioning. The shims can be removed if
libpthread is given a version bump.
Reviewed by: davidxu
