From: David Wells <wellsd2@rpi.edu>
Date: Sun, 28 May 2017 17:35:17 +0000 (-0400)
Subject: Fix tests/base/task_09.cc.
X-Git-Tag: v9.0.0-rc1~1568^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=979bd39e5d568edbe1ba5e28e1735214bb764513;p=dealii.git

Fix tests/base/task_09.cc.

The current implementation of the Task class will call join() on the created
thread in its destructor. Hence, the tasks in the loop run in sequence instead
of in parallel since they immediately go out of scope after each loop iteration,
which is not the point of the test.
---

diff --git a/tests/base/task_09.cc b/tests/base/task_09.cc
index d764518c94..db2b79931a 100644
--- a/tests/base/task_09.cc
+++ b/tests/base/task_09.cc
@@ -65,8 +65,17 @@ int main()
   deallog.attach(logfile);
   deallog.threshold_double(1.e-10);
 
-  for (unsigned int i=0; i<MultithreadInfo::n_cores()*2; ++i)
-    Threads::new_task (outer);
+  const std::size_t n_tasks = MultithreadInfo::n_cores()*2;
+  // Since this test relies on providing more tasks than there are cores,
+  // reset the concurrency limit that exists in tests.h:
+  MultithreadInfo::set_thread_limit(n_tasks);
+  std::vector<Threads::Task<void>> tasks(n_tasks);
+  for (std::size_t task_n=0; task_n<n_tasks; ++task_n)
+    {
+      // We must save each task, otherwise it will join before the next loop
+      // iteration
+      tasks.emplace_back(Threads::new_task(outer));
+    }
 
   deallog << "OK" << std::endl;
 }