plugin/plugin-gcn.c: Fix error handling of GOMP_OFFLOAD_openacc_async_construct

Follow up to r15-5392-g884637b6362391. As the name implies,
GOMP_OFFLOAD_openacc_async_construct is also externally called.
Hence, partially revert previous commit to permit unlocking handling
in oacc-async.c's lookup_goacc_asyncqueue by not failing fatally.

Hence, also the other (indirect) callers had to be updated:
GOMP_OFFLOAD_dev2dev fails now with 'false' and
GOMP_OFFLOAD_async_run fatally.

libgomp/ChangeLog:

	* plugin/plugin-gcn.c (GOMP_OFFLOAD_dev2dev, GOMP_OFFLOAD_async_run):
	Handle omp_async_queue == NULL after call to maybe_init_omp_async.
	(GOMP_OFFLOAD_openacc_async_construct): Use error not fatal error,
	partially reverting r15-5392.

1 files changed, 8 insertions, 6 deletions

diff --git a/libgomp/plugin/plugin-gcn.c b/libgomp/plugin/plugin-gcn.c
index d26b936..239acf8 100644
--- a/libgomp/plugin/plugin-gcn.c
+++ b/libgomp/plugin/plugin-gcn.c
@@ -3939,6 +3939,8 @@ GOMP_OFFLOAD_dev2dev (int device, void *dst, const void *src, size_t n)
     {
       struct agent_info *agent = get_agent_info (device);
       maybe_init_omp_async (agent);
+      if (!agent->omp_async_queue)
+	return false;
       queue_push_copy (agent->omp_async_queue, dst, src, n);
       return true;
     }
@@ -4350,6 +4352,8 @@ GOMP_OFFLOAD_async_run (int device, void *tgt_fn, void *tgt_vars,
     }
 
   maybe_init_omp_async (agent);
+  if (!agent->omp_async_queue)
+    GOMP_PLUGIN_fatal ("Asynchronous queue initialization failed");
   queue_push_launch (agent->omp_async_queue, kernel, tgt_vars, kla);
   queue_push_callback (agent->omp_async_queue,
 		       GOMP_PLUGIN_target_task_completion, async_data);
@@ -4388,9 +4392,7 @@ GOMP_OFFLOAD_openacc_async_exec (void (*fn_ptr) (void *),
   gcn_exec (kernel, devaddrs, dims, targ_mem_desc, true, aq);
 }
 
-/* Create a new asynchronous thread and queue for running future kernels;
-   issues a fatal error if the queue cannot be created as all callers expect
-   that the queue exists.  */
+/* Create a new asynchronous thread and queue for running future kernels.  */
 
 struct goacc_asyncqueue *
 GOMP_OFFLOAD_openacc_async_construct (int device)
@@ -4418,17 +4420,17 @@ GOMP_OFFLOAD_openacc_async_construct (int device)
 
   if (pthread_mutex_init (&aq->mutex, NULL))
     {
-      GOMP_PLUGIN_fatal ("Failed to initialize a GCN agent queue mutex");
+      GOMP_PLUGIN_error ("Failed to initialize a GCN agent queue mutex");
       return NULL;
     }
   if (pthread_cond_init (&aq->queue_cond_in, NULL))
     {
-      GOMP_PLUGIN_fatal ("Failed to initialize a GCN agent queue cond");
+      GOMP_PLUGIN_error ("Failed to initialize a GCN agent queue cond");
       return NULL;
     }
   if (pthread_cond_init (&aq->queue_cond_out, NULL))
     {
-      GOMP_PLUGIN_fatal ("Failed to initialize a GCN agent queue cond");
+      GOMP_PLUGIN_error ("Failed to initialize a GCN agent queue cond");
       return NULL;
     }