Wait all evernts

paddle/fluid/framework/parallel_executor.cc

@@ -420,11 +420,11 @@ struct NCCLAllReduceOpHandle : public OpHandle {
       }
     } else {
       if (events_.size() > 1) {
-        int dev_id =
-            boost::get<platform::CUDAPlace>(waited_dev->GetPlace()).device;
         auto stream =
             static_cast<platform::CUDADeviceContext *>(waited_dev)->stream();
-        PADDLE_ENFORCE(cudaStreamWaitEvent(stream, events_[dev_id], 0));
+        for (auto &ev : events_) {
+          PADDLE_ENFORCE(cudaStreamWaitEvent(stream, ev.second, 0));
+        }
       }
     }
   }

python/paddle/fluid/tests/unittests/test_parallel_executor.py

@@ -47,7 +47,7 @@ class ParallelExecutor(unittest.TestCase):
                 dtypes=['float32', 'int64'])
             img, label = fluid.layers.read_file(reader)
             hidden = img
-            for _ in xrange(2):
+            for _ in xrange(4):
                 hidden = fluid.layers.fc(
                     hidden,
                     size=200,
@@ -60,7 +60,7 @@ class ParallelExecutor(unittest.TestCase):
             adam = fluid.optimizer.Adam()
             adam.minimize(loss)
         act_places = []
-        for each in [fluid.CUDAPlace(0), fluid.CUDAPlace(1)]:
+        for each in [fluid.CUDAPlace(0)]:
             p = fluid.core.Place()
             p.set_place(each)
             act_places.append(p)