Failing to rethrow a __forced_unwind exception is very bad.
This patch ensures we rethrow them in async tasks, and makes the
shared state ready with a broken_promise so that waiting threads
don't block forever. That seems reasonable to me, does anyone have any
better ideas?
Tested x86_64-linux, will wait for feedback before committing.
commit 8d4a49e0391269380b160bd277339f740716de0c
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Tue May 13 15:35:29 2014 +0100
* include/std/condition_variable (condition_variable_any::_Unlock): Do
not swallow __forced_unwind.
* include/std/future (__future_base::_Task_setter): Likewise.
(__future_base::_Async_state_impl): Turn __forced_unwind into broken
promise and rethrow.
* include/std/mutex (try_lock): Likewise.
* testsuite/30_threads/async/forced_unwind.cc: New.
* testsuite/30_threads/packaged_task/forced_unwind.cc: New.
diff --git a/libstdc++-v3/include/std/condition_variable b/libstdc++-v3/include/std/condition_variable
index fc111dd..921cb83 100644
--- a/libstdc++-v3/include/std/condition_variable
+++ b/libstdc++-v3/include/std/condition_variable
@@ -189,7 +189,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
~_Unlock() noexcept(false)
{
if (uncaught_exception())
- __try { _M_lock.lock(); } __catch(...) { }
+ {
+ __try
+ { _M_lock.lock(); }
+ __catch(const __cxxabiv1::__forced_unwind&)
+ { __throw_exception_again; }
+ __catch(...)
+ { }
+ }
else
_M_lock.lock();
}
diff --git a/libstdc++-v3/include/std/future b/libstdc++-v3/include/std/future
index 717ce71..8972ecf 100644
--- a/libstdc++-v3/include/std/future
+++ b/libstdc++-v3/include/std/future
@@ -1231,6 +1231,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
_M_result->_M_set(_M_fn());
}
+ __catch(const __cxxabiv1::__forced_unwind&)
+ {
+ __throw_exception_again; // will cause broken_promise
+ }
__catch(...)
{
_M_result->_M_error = current_exception();
@@ -1250,6 +1254,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
_M_fn();
}
+ __catch(const __cxxabiv1::__forced_unwind&)
+ {
+ __throw_exception_again; // will cause broken_promise
+ }
__catch(...)
{
_M_result->_M_error = current_exception();
@@ -1510,7 +1518,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
: _M_result(new _Result<_Res>()), _M_fn(std::move(__fn))
{
_M_thread = std::thread{ [this] {
- _M_set_result(_S_task_setter(_M_result, _M_fn));
+ __try
+ {
+ _M_set_result(_S_task_setter(_M_result, _M_fn));
+ }
+ __catch (const __cxxabiv1::__forced_unwind&)
+ {
+ // make the shared state ready on thread cancellation
+ if (static_cast<bool>(_M_result))
+ this->_M_break_promise(std::move(_M_result));
+ __throw_exception_again;
+ }
} };
}
diff --git a/libstdc++-v3/include/std/mutex b/libstdc++-v3/include/std/mutex
index 3d70754..f6b851c 100644
--- a/libstdc++-v3/include/std/mutex
+++ b/libstdc++-v3/include/std/mutex
@@ -44,6 +44,7 @@
#include <bits/functexcept.h>
#include <bits/gthr.h>
#include <bits/move.h> // for std::swap
+#include <bits/cxxabi_forced.h>
#ifdef _GLIBCXX_USE_C99_STDINT_TR1
@@ -631,6 +632,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
auto __locks = std::tie(__l1, __l2, __l3...);
__try
{ __try_lock_impl<0>::__do_try_lock(__locks, __idx); }
+ __catch(const __cxxabiv1::__forced_unwind&)
+ { __throw_exception_again; }
__catch(...)
{ }
return __idx;
diff --git a/libstdc++-v3/testsuite/30_threads/async/forced_unwind.cc b/libstdc++-v3/testsuite/30_threads/async/forced_unwind.cc
new file mode 100644
index 0000000..7b0a492
--- /dev/null
+++ b/libstdc++-v3/testsuite/30_threads/async/forced_unwind.cc
@@ -0,0 +1,45 @@
+// { dg-do run { target *-*-linux* *-*-gnu* } }
+// { dg-options " -std=gnu++11 -pthread" { target *-*-linux* *-*-gnu* } }
+// { dg-require-cstdint "" }
+// { dg-require-gthreads "" }
+// { dg-require-atomic-builtins "" }
+
+// Copyright (C) 2014 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/>.
+
+// Test (non-standard) handling of __forced_unwind exception.
+
+#include <future>
+#include <stdexcept>
+#include <pthread.h>
+#include <testsuite_hooks.h>
+
+void f() { pthread_exit(nullptr); }
+
+int main()
+{
+ auto fut = std::async(std::launch::async, f);
+ try
+ {
+ fut.get();
+ throw std::logic_error("Unreachable");
+ }
+ catch (const std::future_error& e)
+ {
+ VERIFY( e.code() == std::future_errc::broken_promise );
+ }
+}
diff --git a/libstdc++-v3/testsuite/30_threads/packaged_task/forced_unwind.cc b/libstdc++-v3/testsuite/30_threads/packaged_task/forced_unwind.cc
new file mode 100644
index 0000000..235ab17
--- /dev/null
+++ b/libstdc++-v3/testsuite/30_threads/packaged_task/forced_unwind.cc
@@ -0,0 +1,48 @@
+// { dg-do run { target *-*-linux* *-*-gnu* } }
+// { dg-options " -std=gnu++11 -pthread" { target *-*-linux* *-*-gnu* } }
+// { dg-require-cstdint "" }
+// { dg-require-gthreads "" }
+// { dg-require-atomic-builtins "" }
+
+// Copyright (C) 2014 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/>.
+
+// Test (non-standard) handling of __forced_unwind exception.
+
+#include <future>
+#include <stdexcept>
+#include <pthread.h>
+#include <testsuite_hooks.h>
+
+void f() { pthread_exit(nullptr); }
+
+int main()
+{
+ std::packaged_task<void()> p(f);
+ auto fut = p.get_future();
+ std::thread t(std::move(p));
+ try
+ {
+ fut.get();
+ throw std::logic_error("Unreachable");
+ }
+ catch (const std::future_error& e)
+ {
+ VERIFY( e.code() == std::future_errc::broken_promise );
+ }
+ t.join();
+}
