Improve decoupled shm handling (#337)

* [DO NOT MERGE] Add shm trace util

* [DO NOT MERGE] Expand shm leak util naming to ipc load

* Revert "[DO NOT MERGE] Expand shm leak util naming to ipc load"

This reverts commit 68906f2.

* Revert "[DO NOT MERGE] Add shm trace util"

This reverts commit 37824ce.

* Fix decoupled shared memory leak

src/python_be.cc

@@ -1328,6 +1328,7 @@ ModelInstanceState::ProcessRequestsDecoupled(
 
   AllocatedSharedMemory<ResponseBatch> response_batch =
       Stub()->ShmPool()->Load<ResponseBatch>(received_message_->Args());
+  received_message_.reset();
 
   uint64_t compute_end_ns = 0;
   SET_TIMESTAMP(compute_end_ns);