std:🧵:hardware_concurrency for platforms that don't offer
sysctl, but do provide a POSIX sysconf and _SC_NPROCESSORS_ONLN.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@161190 91177308-0d34-0410-b5e6-96231b3b80d8
section in libc++. This requires a recompiled dylib. Failure to rebuild
the dylib will result in a link-time error if and only if the functions from
[util.smartptr.shared.atomic] are used.
The implementation is not lock free. After considerable thought, I know of no
way to make the implementation lock free. Ideas welcome along that front. But
changing the ABI of shared_ptr is not on the table at this point.
The mutex used to lock these function is encapsulated by std::__sp_mut. The
only thing the client knows about std::__sp_mut is that it has a void* data
member, can't be constructed, and has lock and unlock members. Within the
binary __sp_mut is currently implemented as a pointer to a std::mutex. That can
change in the future without disturbing the ABI (as long as sizeof(__sp_mut)
remains constant.
I specifically did not make __sp_mut a spin lock as I have a pathological
distrust of spin locks. Testing on OS X reveals that the use of std::mutex in
this role is not a large performance penalty as long as the contention for the
mutex is low (more likely to get the lock than to have to wait). In the future
we can still make __sp_mut a spin lock if that is what is desired (without ABI
damage).
The dylib contains 16 __sp_mut's to be chosen based on the hash of the address
of the shared_ptr. The constant 16 is a ball-park reasonable space/time
tradeoff.
std::hash<T*> was changed to call __murmur2_or_cityhash, instead of the identity
function. I had thought we had already done this, but I was mistaken.
All of this is under #if __has_feature(cxx_atomic) even though the
implementation is not lock free, because the signatures require access to
std::memory_order, which is currently available only under
__has_feature(cxx_atomic).
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@160940 91177308-0d34-0410-b5e6-96231b3b80d8
based on the LIBCXXRT and _LIBCPPABI_VERSION defines, but those files
do not currently include <cxxabi.h> in the non __APPLE__ case. The
attached patch updates those files so that for non __APPLE__ builds
<cxxabi.h> is included if available or if LIBCXXRT is set. I'm
modeling this on the recent updates to exception.cpp.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@160790 91177308-0d34-0410-b5e6-96231b3b80d8
out of the box on Linux systems. If you're building against libc++abi, you
still need to make sure it can find <cxxabi.h> so it knows not to export
symbols which libc++abi provides.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@155091 91177308-0d34-0410-b5e6-96231b3b80d8
Solaris not providing some of the locales that the test suite uses.
Note: This depends on an xlocale (partial) implementation for Solaris and a
couple of fixed standard headers. These will be committed to a branch later
today.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@151720 91177308-0d34-0410-b5e6-96231b3b80d8
libc++ now mostly works on FreeBSD with libcxxrt and this patch applied to the base system:
http://lists.freebsd.org/pipermail/freebsd-hackers/attachments/20110920/e666632c/xlocale-0001.obj
Summary of tests on FreeBSD:
****************************************************
Results for /root/libcxx/test:
using FreeBSD clang version 3.0 (trunk 135360) 20110717
Target: x86_64-unknown-freebsd9.0
Thread model: posix
with -std=c++0x -stdlib=libc++ -I/root/libcxx/include -L/root/libcxx/build/lib
----------------------------------------------------
sections without tests : 1
sections with failures : 48
sections without failures: 1015
+ ----
total number of sections : 1064
----------------------------------------------------
number of tests failed : 145
number of tests passed : 4179
+ ----
total number of tests : 4324
****************************************************
(Many due to this clang version not supporting C++ atomics)
More fixes to follow...
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@140245 91177308-0d34-0410-b5e6-96231b3b80d8