[PATCH 1/4] openacc: Async fix for lib-94 testcase

[Julian Brown]

The test case performs an asynchronous host-to-device copy and then
immediately clobbers the data on the host via "memset", leading to a race
condition.  This patch moves the memset after an acc_wait call instead.

Tested with offloading to AMD GCN.

I can probably self-approve this as a testcase change only, unless
anyone objects.

Thanks,

Julian

2021-06-29  Julian Brown  <jul...@codesourcery.com>

libgomp/
        * testsuite/libgomp.oacc-c-c++-common/lib-94.c: Fix race condition.
---
 libgomp/testsuite/libgomp.oacc-c-c++-common/lib-94.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/lib-94.c 
b/libgomp/testsuite/libgomp.oacc-c-c++-common/lib-94.c
index 54497237b0c..baa3ac83f04 100644
--- a/libgomp/testsuite/libgomp.oacc-c-c++-common/lib-94.c
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/lib-94.c
@@ -22,10 +22,10 @@ main (int argc, char **argv)
 
   acc_copyin_async (h, N, async);
 
-  memset (h, 0, N);
-
   acc_wait (async);
 
+  memset (h, 0, N);
+
   acc_copyout_async (h, N, async + 1);
 
   acc_wait (async + 1);
-- 
2.29.2