Address race condition

Author: aseering

google/cloud/spanner_v1/snapshot.py

@@ -616,6 +616,10 @@ def _get_streamed_result_set(
         if self._transaction_id is None:
             is_inline_begin = True
             self._lock.acquire()
+            if self._transaction_id is not None:
+                is_inline_begin = False
+                self._lock.release()
+                request.transaction = TransactionSelector(id=self._transaction_id)
 
         iterator = _restart_on_unavailable(
             method=method,

google/cloud/spanner_v1/transaction.py

@@ -497,6 +497,9 @@ def execute_update(
         if self._transaction_id is None:
             is_inline_begin = True
             self._lock.acquire()
+            if self._transaction_id is not None:
+                is_inline_begin = False
+                self._lock.release()
 
         execute_sql_request = ExecuteSqlRequest(
             session=session.name,
@@ -651,6 +654,9 @@ def batch_update(
         if self._transaction_id is None:
             is_inline_begin = True
             self._lock.acquire()
+            if self._transaction_id is not None:
+                is_inline_begin = False
+                self._lock.release()
 
         execute_batch_dml_request = ExecuteBatchDmlRequest(
             session=session.name,