Adding non-blocking (on destruction) service executors

hpx/runtime/threads/executors/service_executors.hpp

@@ -68,6 +68,9 @@ namespace hpx { namespace threads { namespace executors
             void add_no_count(closure_type&& f);
             void thread_wrapper(closure_type&& f);
 
+            // detaches this object from the underlying thread pool object
+            void detach();
+
         protected:
             // Return the requested policy element
             std::size_t get_policy_element(
@@ -79,6 +82,7 @@ namespace hpx { namespace threads { namespace executors
             mutex_type mtx_;
             hpx::util::atomic_count task_count_;
             compat::condition_variable shutdown_cv_;
+            bool blocking_;
         };
     }
 
@@ -179,4 +183,4 @@ namespace hpx { namespace threads { namespace executors
 
 #include <hpx/config/warnings_suffix.hpp>
 
-#endif /*HPX_RUNTIME_THREADS_EXECUTORS_SERVICE_EXECUTOR_HPP*/
+#endif /* HPX_RUNTIME_THREADS_EXECUTORS_SERVICE_EXECUTOR_HPP */

hpx/runtime/threads/run_as_os_thread.hpp

@@ -1,4 +1,4 @@
-//  Copyright (c) 2016 Hartmut Kaiser
+//  Copyright (c) 2016-2017 Hartmut Kaiser
 //
 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
@@ -27,8 +27,10 @@ namespace hpx { namespace threads
         HPX_ASSERT(get_self_ptr() != nullptr);
 
         parallel::execution::io_pool_executor scheduler;
-        return parallel::execution::async_execute(scheduler,
+        auto result = parallel::execution::async_execute(scheduler,
             std::forward<F>(f), std::forward<Ts>(vs)...);
+        scheduler.detach();
+        return result;
     }
 }}
 

hpx/runtime/threads/thread_executor.hpp

@@ -196,6 +196,11 @@ namespace hpx { namespace threads
                 return create_id(reinterpret_cast<std::size_t>(this));
             }
 
+            virtual void detach()
+            {
+                // by default, do nothing
+            }
+
         protected:
             static executor_id create_id(std::size_t id)
             {
@@ -429,6 +434,11 @@ namespace hpx { namespace threads
                 stacksize, ec);
         }
 
+        void detach()
+        {
+            executor_data_->detach();
+        }
+
         /// Return a reference to the default executor for this process.
         static scheduled_executor& default_executor();
     };

src/runtime/threads/executors/service_executor.cpp

@@ -34,7 +34,8 @@ namespace hpx { namespace threads { namespace executors { namespace detail
     service_executor::service_executor(
             char const* pool_name, char const* pool_name_suffix)
       : pool_(get_thread_pool(pool_name, pool_name_suffix)),
-        task_count_(0)
+        task_count_(0),
+        blocking_(true)
     {
         if (!pool_) {
             HPX_THROW_EXCEPTION(bad_parameter,
@@ -46,18 +47,27 @@ namespace hpx { namespace threads { namespace executors { namespace detail
     service_executor::~service_executor()
     {
         std::unique_lock<mutex_type> l(mtx_);
-        while (task_count_ > 0)
+        if (blocking_)
         {
-            // We need to cancel the wait process here, since we might block
-            // other running HPX threads.
-            shutdown_cv_.wait_for(l, std::chrono::seconds(1));
-            if (hpx::threads::get_self_ptr())
+            while (task_count_ > 0)
             {
-                hpx::this_thread::suspend();
+                // We need to cancel the wait process here, since we might block
+                // other running HPX threads.
+                shutdown_cv_.wait_for(l, std::chrono::seconds(1));
+                if (hpx::threads::get_self_ptr())
+                {
+                    hpx::this_thread::suspend();
+                }
             }
         }
     }
 
+    void service_executor::detach()
+    {
+        std::unique_lock<mutex_type> l(mtx_);
+        blocking_ = false;
+    }
+
     void service_executor::thread_wrapper(closure_type&& f) //-V669
     {
         f();                          // execute the actual thread function
@@ -79,15 +89,17 @@ namespace hpx { namespace threads { namespace executors { namespace detail
         typedef void result_type;
 
         thread_wrapper_helper(
-            service_executor* exec
-          , service_executor::closure_type&& f
-        ) : exec_(exec)
+                service_executor* exec, service_executor::closure_type&& f)
+          : exec_(exec)
           , f_(std::move(f))
-        {}
+        {
+            intrusive_ptr_add_ref(exec);
+        }
 
         result_type invoke()
         {
             exec_->thread_wrapper(std::move(f_));
+            intrusive_ptr_release(exec_);
         }
 
         service_executor* exec_;
@@ -128,19 +140,21 @@ namespace hpx { namespace threads { namespace executors { namespace detail
     {
         typedef void result_type;
 
-        delayed_add_helper(
-            service_executor* exec
-          , service_executor::closure_type&& f
-          , boost::asio::io_service& io_service
-          , util::steady_clock::time_point const& abs_time
-        ) : exec_(exec)
+        delayed_add_helper(service_executor* exec,
+                service_executor::closure_type&& f,
+                boost::asio::io_service& io_service,
+                util::steady_clock::time_point const& abs_time)
+          : exec_(exec)
           , f_(std::move(f))
           , timer_(io_service, abs_time)
-        {}
+        {
+            intrusive_ptr_add_ref(exec);
+        }
 
         result_type invoke()
         {
             exec_->add_no_count(std::move(f_));
+            intrusive_ptr_release(exec_);
         }
 
         service_executor* exec_;

tests/regressions/threads/CMakeLists.txt

@@ -7,6 +7,7 @@
 set(tests
     block_os_threads_1036
     resume_priority
+    run_as_os_thread_lockup_2991
     thread_data_1111
     thread_pool_executor_1112
     thread_rescheduling

tests/regressions/threads/run_as_os_thread_lockup_2991.cpp

@@ -0,0 +1,43 @@
+//  Copyright (c) 2017 Maciej Brodowicz
+//
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#include <hpx/hpx_init.hpp>
+#include <hpx/hpx.hpp>
+#include <hpx/runtime/threads/run_as_os_thread.hpp>
+
+#include <iostream>
+#include <mutex>
+#include <thread>
+
+std::mutex mtx;
+
+void locker()
+{
+    std::cout << std::this_thread::get_id() << ": about to lock mutex\n";
+    std::lock_guard<std::mutex> lock(mtx);
+    std::cout << std::this_thread::get_id() << ": mutex locked\n";
+}
+
+int hpx_main()
+{
+    {
+        std::cout << std::this_thread::get_id() << ": about to lock mutex\n";
+        std::lock_guard<std::mutex> lock(mtx);
+        std::cout << std::this_thread::get_id() << ": mutex locked\n";
+
+        std::cout << std::this_thread::get_id() << ": about to run on io thread\n";
+        hpx::threads::run_as_os_thread(locker);
+        //sleep(2);
+    }
+    std::cout << std::this_thread::get_id() << ": exiting\n";
+
+    return hpx::finalize();
+}
+
+int main(int argc, char **argv)
+{
+    return hpx::init(argc, argv);
+}
+