!959 iterator case, control edge move up to switch

From: @wangxiaotian22
Reviewed-by: @xchu42,@wqtshg
Signed-off-by: @ji_chen

ge/graph/build/stream_allocator.cc

@@ -1013,6 +1013,24 @@ bool StreamAllocator::IsActivated(int64_t stream_id) const {
   return false;
 }
 
+// Iteraotor loop :
+// StreamSwitch  ->  StreamActive
+// FpBp loop:
+// StreamSwitch  ->  AssignAdd  ->  StreamActive
+NodePtr FindSwitchNodeBeforeLoopActiveNode(const NodePtr &active_node) {
+  for (auto pre_node : active_node->GetInControlNodes()) {
+    if (pre_node->GetType() == STREAMSWITCH) {
+      return pre_node;
+    }
+    for (auto pre_pre_node : pre_node->GetInControlNodes()) {
+      if (pre_pre_node->GetType() == STREAMSWITCH) {
+        return pre_pre_node;
+      }
+    }
+  }
+  return nullptr;
+}
+
 Status StreamAllocator::SetActiveStreamsForLoop() {
   vector<uint32_t> loop_active_streams;
   for (int64_t stream_id = 0; stream_id < stream_num_; stream_id++) {
@@ -1038,6 +1056,13 @@ Status StreamAllocator::SetActiveStreamsForLoop() {
     bool is_loop_active = false;
     if (AttrUtils::GetBool(node->GetOpDesc(), ATTR_NAME_IS_LOOP_ACTIVE, is_loop_active) && is_loop_active) {
       vector<string> activated_label_list;
+
+      NodePtr pre_switch_node = FindSwitchNodeBeforeLoopActiveNode(node);
+      if (pre_switch_node == nullptr) {
+        GELOGE(FAILED, "find switch node before loop active node %s failed", node->GetName().c_str());
+        return FAILED;
+      }
+
       if (!AttrUtils::GetListStr(node->GetOpDesc(), ATTR_NAME_ACTIVE_LABEL_LIST, activated_label_list) ||
           activated_label_list.empty()) {
         GE_CHK_BOOL_EXEC(AttrUtils::SetListInt(node->GetOpDesc(), ATTR_NAME_ACTIVE_STREAM_LIST, loop_active_streams),
@@ -1053,7 +1078,7 @@ Status StreamAllocator::SetActiveStreamsForLoop() {
         // it may cause some stream actived by iterator next step when this stream still alive.
         // If above situation happen, active message will lose, cause process block in next iteration.
         // In order to avoid this abnormal happen,
-        // add event between each last node and iterator active node in target active stream
+        // add event between each last node and iterator switch node
         GELOGI("there are %zu next iterator target streams has streamswitch node.", streams_skip_iterator_event.size());
         for (auto iter : stream_id_to_last_node) {
           if (streams_skip_iterator_event.find(iter.first) != streams_skip_iterator_event.end()) {
@@ -1067,7 +1092,7 @@ Status StreamAllocator::SetActiveStreamsForLoop() {
             continue;
           }
           AddSendEventId(iter.second, event_num_);
-          AddRecvEventId(node, event_num_);
+          AddRecvEventId(pre_switch_node, event_num_);
           event_num_++;
         }