Patchwork [v3] fix PR 54297 - segfaults with std::async

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Submitter Jonathan Wakely
Date Aug. 25, 2012, 11:02 p.m.
Message ID <CAH6eHdT=GnPWyRDcBWG5c6kmiEOme7mfr2m_H54bK56J_wcO9A@mail.gmail.com>
Download mbox | patch
Permalink /patch/179993/
State New
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Comments

Jonathan Wakely - Aug. 25, 2012, 11:02 p.m.
This fixes a stupid mistake I made where the functor and asynchronous
result can go out of scope before the async thread is joined.

The _Async_state_common destructor still needs to be exported from the
library, which is what the macro hack is for.

        PR libstdc++/54297
        * include/std/future (~_Async_state_impl): Join thread before
        derived class members are destroyed.
        (~_Async_state_common): Only define non-trivial destructor when
        included from future.cc for ABI compatibility reasons.
        * src/c++11/future.cc (_GLIBCXX_ABI_COMPAT_ASYNC): Define.
        * testsuite/30_threads/async/54297.cc: New.

Tested x86_64-linux, committed to trunk and 4.7
commit 1006a99bff42b02e8ff7d2eaa696d639cfe3d0d7
Author: Jonathan Wakely <jwakely.gcc@gmail.com>
Date:   Sat Aug 25 19:25:27 2012 +0100

    	PR libstdc++/54297
    	* include/std/future (~_Async_state_impl): Join thread before
    	derived class members are destroyed.
    	(~_Async_state_common): Only define non-trivial destructor when
    	included from future.cc for ABI compatibility reasons.
    	* src/c++11/future.cc (_GLIBCXX_ABI_COMPAT_ASYNC): Define.
    	* testsuite/30_threads/async/54297.cc: New.

Patch

diff --git a/libstdc++-v3/include/std/future b/libstdc++-v3/include/std/future
index a8d7112..feae382 100644
--- a/libstdc++-v3/include/std/future
+++ b/libstdc++-v3/include/std/future
@@ -1427,10 +1427,10 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
   class __future_base::_Async_state_common : public __future_base::_State_base
   {
   protected:
-#ifdef _GLIBCXX_HAVE_TLS
+#if defined(_GLIBCXX_HAVE_TLS) && defined(_GLIBCXX_ABI_COMPAT_ASYNC)
     ~_Async_state_common();
 #else
-    ~_Async_state_common() { _M_join(); }
+    ~_Async_state_common() = default;
 #endif
 
     // Allow non-timed waiting functions to block until the thread completes,
@@ -1457,6 +1457,8 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
         } };
       }
 
+      ~_Async_state_impl() { _M_join(); }
+
     private:
       typedef __future_base::_Ptr<_Result<_Res>> _Ptr_type;
       _Ptr_type _M_result;
diff --git a/libstdc++-v3/src/c++11/future.cc b/libstdc++-v3/src/c++11/future.cc
index 380c3a4..eaea393 100644
--- a/libstdc++-v3/src/c++11/future.cc
+++ b/libstdc++-v3/src/c++11/future.cc
@@ -22,6 +22,8 @@ 
 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 // <http://www.gnu.org/licenses/>.
 
+#define _GLIBCXX_ABI_COMPAT_ASYNC
+
 #include <future>
 
 namespace
@@ -86,6 +88,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
   __future_base::_State_base::~_State_base() = default;
 
 #ifdef _GLIBCXX_HAVE_TLS
+  // Exported for compatibility with ABI version 3.4.17
   __future_base::_Async_state_common::~_Async_state_common() { _M_join(); }
 
   // Explicit instantiation due to -fno-implicit-instantiation.
diff --git a/libstdc++-v3/testsuite/30_threads/async/54297.cc b/libstdc++-v3/testsuite/30_threads/async/54297.cc
new file mode 100644
index 0000000..1d4d0a4
--- /dev/null
+++ b/libstdc++-v3/testsuite/30_threads/async/54297.cc
@@ -0,0 +1,50 @@ 
+// { dg-do run { target *-*-freebsd* *-*-netbsd* *-*-linux* *-*-solaris* *-*-cygwin *-*-darwin* powerpc-ibm-aix* } }
+// { dg-options " -std=gnu++0x -pthread" { target *-*-freebsd* *-*-netbsd* *-*-linux* powerpc-ibm-aix* } }
+// { dg-options " -std=gnu++0x -pthreads" { target *-*-solaris* } }
+// { dg-options " -std=gnu++0x " { target *-*-cygwin *-*-darwin* } }
+// { dg-require-cstdint "" }
+// { dg-require-gthreads "" }
+// { dg-require-atomic-builtins "" }
+
+// Copyright (C) 2012 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <chrono>
+#include <thread>
+#include <future>
+#include <set>
+#include <testsuite_hooks.h>
+
+struct Task;
+
+std::set<const Task*> dead_tasks;
+
+struct Task
+{
+  ~Task() { dead_tasks.insert(this); }
+
+  void operator()() const
+  {
+    std::this_thread::sleep_for(std::chrono::seconds(1));
+    VERIFY( dead_tasks.count(this) == 0 );
+  }
+};
+
+int main()
+{
+  std::async(std::launch::async, Task());
+}