Author: marshall
Date: Sun Nov 3 09:43:35 2013
New Revision: 193960
URL: http://llvm.org/viewvc/llvm-project?rev=193960&view=rev
Log:
Fix LWG Issue 2078. Make std::async(policy,...) try multiple policies until one succeeds.
Modified:
libcxx/trunk/include/future
libcxx/trunk/www/cxx1y_status.html
Modified: libcxx/trunk/include/future
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/future?rev=193960&r1=193959&r2=193960&view=diff
==============================================================================
--- libcxx/trunk/include/future (original)
+++ libcxx/trunk/include/future Sun Nov 3 09:43:35 2013
@@ -2331,20 +2331,32 @@ private:
}
};
+bool __does_policy_contain(launch __policy, launch __value )
+{ return (int(__policy) & int(__value)) != 0; }
+
template <class _Fp, class... _Args>
future<typename __invoke_of<typename decay<_Fp>::type, typename decay<_Args>::type...>::type>
async(launch __policy, _Fp&& __f, _Args&&... __args)
{
typedef __async_func<typename decay<_Fp>::type, typename decay<_Args>::type...> _BF;
typedef typename _BF::_Rp _Rp;
- future<_Rp> __r;
- if (int(__policy) & int(launch::async))
- __r = _VSTD::__make_async_assoc_state<_Rp>(_BF(__decay_copy(_VSTD::forward<_Fp>(__f)),
+
+#ifndef _LIBCPP_NO_EXCEPTIONS
+ try
+ {
+#endif
+ if (__does_policy_contain(__policy, launch::async))
+ return _VSTD::__make_async_assoc_state<_Rp>(_BF(__decay_copy(_VSTD::forward<_Fp>(__f)),
__decay_copy(_VSTD::forward<_Args>(__args))...));
- else if (int(__policy) & int(launch::deferred))
- __r = _VSTD::__make_deferred_assoc_state<_Rp>(_BF(__decay_copy(_VSTD::forward<_Fp>(__f)),
+#ifndef _LIBCPP_NO_EXCEPTIONS
+ }
+ catch ( ... ) { if (__policy == launch::async) throw ; }
+#endif
+
+ if (__does_policy_contain(__policy, launch::deferred))
+ return _VSTD::__make_deferred_assoc_state<_Rp>(_BF(__decay_copy(_VSTD::forward<_Fp>(__f)),
__decay_copy(_VSTD::forward<_Args>(__args))...));
- return __r;
+ return future<_Rp>{};
}
template <class _Fp, class... _Args>
Modified: libcxx/trunk/www/cxx1y_status.html
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/www/cxx1y_status.html?rev=193960&r1=193959&r2=193960&view=diff
==============================================================================
--- libcxx/trunk/www/cxx1y_status.html (original)
+++ libcxx/trunk/www/cxx1y_status.html Sun Nov 3 09:43:35 2013
@@ -196,7 +196,7 @@
<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2194">2194</a></td><td>Impossible container requirements for adaptor types</td><td>Chicago</td><td>Complete</td></tr>
<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2013">2013</a></td><td>Do library implementers have the freedom to add constexpr?</td><td>Chicago</td><td>Complete</td></tr>
<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2018">2018</a></td><td>regex_traits::isctype Returns clause is wrong</td><td>Chicago</td><td>Complete</td></tr>
- <tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2078">2078</a></td><td>Throw specification of async() incomplete</td><td>Chicago</td><td></td></tr>
+ <tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2078">2078</a></td><td>Throw specification of async() incomplete</td><td>Chicago</td><td>Complete</td></tr>
<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2097">2097</a></td><td>packaged_task constructors should be constrained</td><td>Chicago</td><td>Complete</td></tr>
<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2100">2100</a></td><td>Timed waiting functions cannot timeout if launch::async policy used</td><td>Chicago</td><td>Complete</td></tr>
<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2120">2120</a></td><td>What should async do if neither 'async' nor 'deferred' is set in policy?</td><td>Chicago</td><td>Complete</td></tr>