This patch introduces two new convenience functions to set the default
thread attributes used for creating threads. This allows a programmer
to set the default thread attributes just once in a process and then
run pthread_create without additional attributes.
Resolves BZ #15618.
pthread_attr_getaffinity_np may write beyond bounds of the input
cpuset buffer if the size of the input buffer is smaller than the
buffer present in the input pthread attributes. Fix is to copy to the
extent of the minimum of the source and the destination.
It is very very possible that the futex syscall returns an
error and that the caller of lll_futex_wake may want to
look at that error and propagate the failure.
This patch allows a caller to see the syscall error.
There are no users of the syscall error at present, but
future cleanups are now be able to check for the error.
--
nplt/
2013-06-10 Carlos O'Donell <carlos@redhat.com>
* sysdeps/unix/sysv/linux/i386/lowlevellock.h
(lll_futex_wake): Return syscall error.
* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h
(lll_futex_wake): Return syscall error.
The sem_post.c file uses atomic functions without including
atomic.h. Add `#include <atomic.h>' to the file to prevent
any compile time warnings when other headers change and
atomic.h isn't implicitly included.
---
nptl/
2013-04-07 Carlos O'Donell <carlos@redhat.com>
* sysdeps/unix/sysv/linux/sem_post.c: Include atomic.h.
Fixes BZ #15337.
Static builds fail with the following warning:
/home/tools/glibc/glibc/nptl/../nptl/sysdeps/unix/sysv/linux/x86_64/cancellation.S:80:
undefined reference to `__GI___pthread_unwind'
When the source is configured with --disable-hidden-plt. This is
because the preprocessor conditional in cancellation.S only checks if
the build is for SHARED, whereas hidden_def is defined appropriately
only for a SHARED build that will have symbol versioning *and* hidden
defs are enabled. The last case is false here.
This reverts the change that allows the POSIX Thread default stack size
to be changed by the environment variable
GLIBC_PTHREAD_DEFAULT_STACKSIZE. It has been requested that more
discussion happen before this change goes into 2.18.
This feature is specifically for the C++ compiler to offload calling
thread_local object destructors on thread program exit, to glibc.
This is to overcome the possible complication of destructors of
thread_local objects getting called after the DSO in which they're
defined is unloaded by the dynamic linker. The DSO is marked as
'unloadable' if it has a constructed thread_local object and marked as
'unloadable' again when all the constructed thread_local objects
defined in it are destroyed.
* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S
(__pthread_cond_timedwait): If possible use FUTEX_WAIT_BITSET to
directly use absolute timeout.
Since the FUTEX_WAIT operation takes a relative timeout, the
pthread_cond_timedwait and other timed function implementations have
to get a relative timeout from the absolute timeout parameter it gets
before it makes the futex syscall. This value is then converted back
into an absolute timeout within the kernel. This is a waste and has
hence been improved upon by a FUTEX_WAIT_BITSET operation (OR'd with
FUTEX_CLOCK_REALTIME to make the kernel use the realtime clock instead
of the default monotonic clock). This was implemented only in the x86
and sh assembly code and not in the C code. This patch implements
support for FUTEX_WAIT_BITSET whenever available (since linux-2.6.29)
for s390 and powerpc.
nptl/
* sysdeps/unix/sysv/linux/sparc/lowlevellock.h (BUSY_WAIT_NOP):
Define when we have v9 instructions available.
* sysdeps/unix/sysv/linux/sparc/sparc64/cpu_relax.S: New file.
* sysdeps/unix/sysv/linux/sparc/sparc32/sparcv9/cpu_relax.S: New
file.
* sysdeps/unix/sysv/linux/sparc/sparc32/sparcv9/Makefile: New
file.
* sysdeps/unix/sysv/linux/sparc/sparc64/Makefile: Add cpu_relax
to libpthread-routines.
The macro pthread_cleanup_push_defer_np in pthread.h has a misaligned
line continuation marker. This marker was previously aligned, but
recent changes have moved it out of alignment. This change realigns
the marker. This also reduces the diff against the hppa version of
pthread.h where the marker is aligned.
[BZ #14652]
When a thread waiting in pthread_cond_wait with a PI mutex is
cancelled after it has returned successfully from the futex syscall
but just before async cancellation is disabled, it enters its
cancellation handler with the mutex held and simply calling a
mutex_lock again will result in a deadlock. Hence, it is necessary to
see if the thread owns the lock and try to lock it only if it doesn't.
[BZ #14568]
* sysdeps/sparc/tls.h (DB_THREAD_SELF_INCLUDE): Delete.
(DB_THREAD_SELF): Use constants for the register offsets. Correct
the case of a 64-bit debugger with a 32-bit inferior.
[BZ #14417]
A futex call with FUTEX_WAIT_REQUEUE_PI returns with the mutex locked
on success. If such a successful thread is pipped to the cond_lock by
another spuriously woken waiter, it could be sent back to wait on the
futex with the mutex lock held, thus causing a deadlock. So it is
necessary that the thread relinquishes the mutex before going back to
sleep.
[BZ #14477]
Add an additional entry in the exception table to jump to
__condvar_w_cleanup2 instead of __condvar_w_cleanup for PI mutexes
when %ebx contains the address of the futex instead of the condition
variable.
Ref gcc.gnu.org/bugzilla/show_bug.cgi?id=52839#c10
Release barriers are needed to ensure that any memory written by
init_routine is seen by other threads before *once_control changes.
In the case of clear_once_control we need to flush any partially
written state.
