[Openmp-commits] [openmp] r274641 - Fix the nowait tests for omp for and omp single

[Jonathan Peyton via Openmp-commits]

Author: jlpeyton
Date: Wed Jul  6 12:26:12 2016
New Revision: 274641

URL: http://llvm.org/viewvc/llvm-project?rev=274641&view=rev
Log:
Fix the nowait tests for omp for and omp single

These tests are now modeled after the sections nowait test where threads wait
to be released in the first construct (either for or single) and the last thread
skips the last for/single construct and releases those threads.  If the test
fails, then it hangs because an unnecessary barrier is executed in between the
constructs.

Modified:
    openmp/trunk/runtime/test/worksharing/for/omp_for_nowait.c
    openmp/trunk/runtime/test/worksharing/single/omp_single_nowait.c

Modified: openmp/trunk/runtime/test/worksharing/for/omp_for_nowait.c
URL: http://llvm.org/viewvc/llvm-project/openmp/trunk/runtime/test/worksharing/for/omp_for_nowait.c?rev=274641&r1=274640&r2=274641&view=diff
==============================================================================
--- openmp/trunk/runtime/test/worksharing/for/omp_for_nowait.c (original)
+++ openmp/trunk/runtime/test/worksharing/for/omp_for_nowait.c Wed Jul  6 12:26:12 2016
@@ -1,42 +1,66 @@
 // RUN: %libomp-compile-and-run
 #include <stdio.h>
 #include "omp_testsuite.h"
-#include "omp_my_sleep.h"
 
-int test_omp_for_nowait()
+/*
+ * This test will hang if the nowait is not working properly.
+ *
+ * It relies on a thread skipping to the second for construct to
+ * release the threads in the first for construct.
+ *
+ * Also, we use static scheduling to guarantee that one
+ * thread will make it to the second for construct.
+ */
+volatile int release;
+volatile int count;
+
+void wait_for_release_then_increment(int rank)
+{
+  fprintf(stderr, "Thread nr %d enters first for construct"
+    " and waits.\n", rank);
+  while (release == 0);
+  #pragma omp atomic
+  count++;
+}
+
+void release_and_increment(int rank)
 {
-  int result;
-  int count;
-  int j;
-  int myarray[LOOPCOUNT];
+  fprintf(stderr, "Thread nr %d sets release to 1\n", rank);
+  release = 1;
+  #pragma omp atomic
+  count++;
+}
 
-  result = 0;
+int test_omp_for_nowait()
+{
+  release = 0;
   count = 0;
 
-  #pragma omp parallel
+  #pragma omp parallel num_threads(4)
   {
     int rank;
     int i;
 
     rank = omp_get_thread_num();
 
-    #pragma omp for nowait
-    for (i = 0; i < LOOPCOUNT; i++) {
-      if (i == 0) {
-        my_sleep(SLEEPTIME);
-        count = 1;
-        #pragma omp flush(count)
+    #pragma omp for schedule(static) nowait
+    for (i = 0; i < 4; i++) {
+      if (i < 3)
+        wait_for_release_then_increment(rank);
+      else {
+        fprintf(stderr, "Thread nr %d enters first for and goes "
+          "immediately to the next for construct to release.\n", rank);
+        #pragma omp atomic
+        count++;
       }
     }
 
-    #pragma omp for
-    for (i = 0; i < LOOPCOUNT; i++) {
-      #pragma omp flush(count)
-      if (count == 0)
-        result = 1;
+    #pragma omp for schedule(static)
+    for (i = 0; i < 4; i++) {
+        release_and_increment(rank);
     }
   }
-  return result;
+  return (count==8);
 }
 
 int main()

Modified: openmp/trunk/runtime/test/worksharing/single/omp_single_nowait.c
URL: http://llvm.org/viewvc/llvm-project/openmp/trunk/runtime/test/worksharing/single/omp_single_nowait.c?rev=274641&r1=274640&r2=274641&view=diff
==============================================================================
--- openmp/trunk/runtime/test/worksharing/single/omp_single_nowait.c (original)
+++ openmp/trunk/runtime/test/worksharing/single/omp_single_nowait.c Wed Jul  6 12:26:12 2016
@@ -2,45 +2,61 @@
 #include <stdio.h>
 #include "omp_testsuite.h"
 
-int my_iterations;
-#pragma omp threadprivate(my_iterations)
+/*
+ * This test will hang if the nowait is not working properly
+ *
+ * It relies on a one thread skipping to the last single construct to
+ * release the threads in the first three single constructs
+ */
+volatile int release;
+volatile int count;
 
-int test_omp_single_nowait()
+void wait_for_release_then_increment(int rank)
 {
-  int nr_iterations;
-  int total_iterations = 0;
-  int i;
+  fprintf(stderr, "Thread nr %d enters first section"
+    " and waits.\n", rank);
+  while (release == 0);
+  #pragma omp atomic
+  count++;
+}
 
-  nr_iterations = 0;
-  my_iterations = 0;
+void release_and_increment(int rank)
+{
+  fprintf(stderr, "Thread nr %d sets release to 1\n", rank);
+  release = 1;
+  #pragma omp atomic
+  count++;
+}
 
-  #pragma omp parallel private(i)
-  {
-    for (i = 0; i < LOOPCOUNT; i++) {
-      #pragma omp single nowait
-      {
-        #pragma omp atomic
-        nr_iterations++;
-      }
-    }
-  }
+int test_omp_single_nowait()
+{
+  release = 0;
+  count = 0;
 
-  #pragma omp parallel private(i)
+  #pragma omp parallel num_threads(4)
   {
-    my_iterations = 0;
-    for (i = 0; i < LOOPCOUNT; i++) {
-      #pragma omp single nowait
-      {
-        my_iterations++;
-      }
+    int rank;
+    rank = omp_get_thread_num ();
+    #pragma omp single nowait
+    {
+      wait_for_release_then_increment(rank);
+    }
+    #pragma omp single nowait
+    {
+      wait_for_release_then_increment(rank);
     }
-    #pragma omp critical
+    #pragma omp single nowait
     {
-      total_iterations += my_iterations;
+      wait_for_release_then_increment(rank);
     }
 
+    #pragma omp single
+    {
+      release_and_increment(rank);
+    }
   }
-  return ((nr_iterations == LOOPCOUNT) && (total_iterations == LOOPCOUNT));
+  // Check to make sure all four singles were executed
+  return (count==4);
 } /* end of check_single_nowait*/
 
 int main()