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Author SHA1 Message Date
Jonathan Roelofs
baed05dd37 Address some post-commit review comments on r217261 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@217276 91177308-0d34-0410-b5e6-96231b3b80d8
 2014-09-05 20:28:44 +00:00
Jonathan Roelofs
8d86b2e686 Allow libc++ to be built on systems without POSIX threads 
If you're crazy enough to want this sort of thing, then add
-D_LIBCPP_HAS_NO_THREADS to your CXXFLAGS and
--param=additiona_features=libcpp-has-no-threads to your lit commnad line.

http://reviews.llvm.org/D3969


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@217271 91177308-0d34-0410-b5e6-96231b3b80d8
 2014-09-05 19:45:05 +00:00
Joerg Sonnenberger
4c6acb5ecd Switch to using C++ style casts. 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@198505 91177308-0d34-0410-b5e6-96231b3b80d8
 2014-01-04 17:43:00 +00:00
Howard Hinnant
e33c2d1926 This should be nothing but a load-time optimization. I'm trying to reduce load time initializers and this is a big one. No visible functionality change intended. 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@177212 91177308-0d34-0410-b5e6-96231b3b80d8
 2013-03-16 00:17:53 +00:00
Howard Hinnant
9c0df1416f Rename uses of _ and __ because these are getting stepped on by macros from other system code. 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@167038 91177308-0d34-0410-b5e6-96231b3b80d8
 2012-10-30 19:06:59 +00:00
Howard Hinnant
96c60b482e Patch contributed by Dev Dude for mingw64 port. 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@162188 91177308-0d34-0410-b5e6-96231b3b80d8
 2012-08-19 15:13:16 +00:00
Howard Hinnant
65f059b842 Despite my pathological distrust of spin locks, the number just don't lie. I've put a small spin in __sp_mut::lock() on std::mutex::try_lock(), which is testing quite well. In my experience, putting in a yield for every failed iteration is also a major performance booster. This change makes one of the performance tests I was using (a highly contended one) run about 20 times faster. 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@160967 91177308-0d34-0410-b5e6-96231b3b80d8
 2012-07-30 17:13:21 +00:00
Howard Hinnant
5fec82dc0d Implement [util.smartptr.shared.atomic]. This is the last unimplemented 
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
 2012-07-30 01:40:57 +00:00
Howard Hinnant
46e9493c68 Appy constexpr to <memory>. Picked up a few missing noexcepts as well. 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@159902 91177308-0d34-0410-b5e6-96231b3b80d8
 2012-07-07 20:56:04 +00:00
Howard Hinnant
5586c020c9 Fix memory leak in converting weak_ptr to shared_ptr 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@147298 91177308-0d34-0410-b5e6-96231b3b80d8
 2011-12-27 22:20:51 +00:00
Howard Hinnant
ec3773c2da Quash a whole bunch of warnings 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@145624 91177308-0d34-0410-b5e6-96231b3b80d8
 2011-12-01 20:21:04 +00:00
Howard Hinnant
1694d23e23 noexcept for <memory>. I've added a few extension noexcept to: allocator_traits<A>::deallocate, allocaate<T>::deallocate, return_temporary_buffer, and default_delete<T>::operator()(T*) const. My rationale was: If a std-dicated noexcept function needs to call another std-defined function, that called function must be noexcept. We're all a little new to noexcept, so things like this are to be expected. Also included fix for broken __is_swappable trait pointed out by Marc Glisse, thanks Marc|. And fixed a test case for is_nothrow_destructible. Destructors are now noexcept by default| 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@132261 91177308-0d34-0410-b5e6-96231b3b80d8
 2011-05-28 14:41:13 +00:00
Howard Hinnant
b64f8b07c1 license change 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@119395 91177308-0d34-0410-b5e6-96231b3b80d8
 2010-11-16 22:09:02 +00:00
Howard Hinnant
28dbbe0596 Dave Zarzycki showed how the efficiency of shared_ptr could be significantly 
increased.  The following program is running 49% faster:

#include <iostream>
#include <memory>
#include <chrono>
#include <vector>
#include "chrono_io"

int main()
{
    typedef std::chrono::high_resolution_clock Clock;
    Clock::time_point t0 = Clock::now();
    {
        std::shared_ptr<int> p(new int (1));
        std::vector<std::shared_ptr<int> > v(1000000, p);
        v.insert(v.begin(), p);
        v.insert(v.begin(), p);
        v.insert(v.begin(), p);
        v.insert(v.begin(), p);
    }
    Clock::time_point t1 = Clock::now();
    std::cout << (t1-t0) << '\n';
}


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@119388 91177308-0d34-0410-b5e6-96231b3b80d8
 2010-11-16 21:33:17 +00:00
Howard Hinnant
16e6e1d72f Fixing whitespace problems 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@111751 91177308-0d34-0410-b5e6-96231b3b80d8
 2010-08-22 00:03:27 +00:00
Howard Hinnant
d444470d6c now works with -fno-exceptions and -fno-rtti 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@110828 91177308-0d34-0410-b5e6-96231b3b80d8
 2010-08-11 17:04:31 +00:00
Howard Hinnant
adff4895b2 patch by Jeffrey Yasskin for porting to Ubuntu Hardy. Everything was accepted except there were some bug fixes needed in <locale> for the __nolocale_* series. For the apple branch I ended up using templates instead of the var_args solution because it seemed both safer and more efficient. 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@104516 91177308-0d34-0410-b5e6-96231b3b80d8
 2010-05-24 17:49:41 +00:00
Howard Hinnant
f5256e16df Wiped out some non-ascii characters that snuck into the copyright. 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@103516 91177308-0d34-0410-b5e6-96231b3b80d8
 2010-05-11 21:36:01 +00:00
Howard Hinnant
bc8d3f97eb libcxx initial import 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@103490 91177308-0d34-0410-b5e6-96231b3b80d8
 2010-05-11 19:42:16 +00:00