Bug fix for hang when tasks used in nested parallel

Bug fix for hang when omp task and nested parallelism used together.
Still some problem remains with task state saving/restoring, but
user's case works fine now. All tasking unit tests passed as well.

Patch by Andrey Churbanov

Differential Revision: http://reviews.llvm.org/D21558

llvm-svn: 273297

1 files changed, 32 insertions, 0 deletions

diff --git a/openmp/runtime/test/tasking/nested_parallel_tasking.c b/openmp/runtime/test/tasking/nested_parallel_tasking.c
new file mode 100644
index 00000000000..4374d6ecda2
--- /dev/null
+++ b/openmp/runtime/test/tasking/nested_parallel_tasking.c
@@ -0,0 +1,32 @@
+// RUN: %libomp-compile-and-run
+#include <stdio.h>
+#include <omp.h>
+
+/*
+ * This test would hang when level instead of active level
+ * used to push task state.
+ */
+
+int main()
+{
+  // If num_threads is changed to a value greater than 1, then the test passes
+  #pragma omp parallel num_threads(1)
+  {
+    #pragma omp parallel
+    printf("Hello World from thread %d\n", omp_get_thread_num());
+  }
+
+  printf("omp_num_threads: %d\n", omp_get_max_threads());
+
+  #pragma omp parallel
+  {
+    #pragma omp master
+    #pragma omp task default(none)
+    {
+      printf("%d is executing this task\n", omp_get_thread_num());
+    }
+  }
+
+  printf("pass\n");
+  return 0;
+}