Add a function timerfd_tracker::enter_critical_section_cancelable,
which is like enter_critical_section but honors a cancel event. Call
this when a timer expires while the timerfd thread is in its inner
loop. This avoids a deadlock if timerfd_tracker::dtor has entered its
critical section and is trying to cancel the thread. See
https://cygwin.com/ml/cygwin/2019-06/msg00096.html.
This patch set implements the Linux syscalls sched_getaffinity,
sched_setaffinity, pthread_getaffinity_np, and pthread_setaffinity_np.
Linux has a straightforward view of the cpu sets used in affinity masks.
They are simply long (1024-bit) bit masks. This code emulates that view
while internally dealing with Windows' distribution of available CPUs among
processor groups.
libX11 provides <X11/Xlocale.h>. The build of libX11 itself adds
include/X11 to the compiler's include path. This results in a name
collision with /usr/include/xlocale.h on case-insensitive filesystems.
Commit 90e35b1eb3 renamed sys/_locale.h to xlocale.h in March 2017 under
the assumption that we should provide the locale_t type in the same file
as on Linux, FreeBSD, and Darwin.
A few weeks later (June 2017), glibc removed the xlocale.h file in favor
of bits/types/locale_t.h, which shouldn't be included directly anyway.
For reference and the reasoning, see
https://sourceware.org/git/?p=glibc.git;a=commit;h=f0be25b6336d
Given the above, revert 90e35b1eb3 and
fix additional usage of xlocale.h.