!8476 Merge CacheOp_dev fixes for HQ system test.

From: @jkl_lee
Reviewed-by: 
Signed-off-by:

mindspore/ccsrc/minddata/dataset/engine/cache/cache_admin_arg.cc

@@ -17,6 +17,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include <signal.h>
 #include <unistd.h>
 #include <algorithm>
 #include <cerrno>
@@ -351,7 +352,10 @@ Status CacheAdminArgHandler::RunCommand() {
       // have to wait for its complete shutdown because the server will shutdown
       // the comm layer as soon as the request is received, and we need to wait
       // on the message queue instead.
-      // The server will remove the queue and we will then wake up.
+      // The server will remove the queue and we will then wake up. But on the safe
+      // side, we will also set up an alarm and kill this proocess if we hang on
+      // the message queue.
+      alarm(15);
       Status dummy_rc;
       (void)msg.ReceiveStatus(&dummy_rc);
       break;

mindspore/ccsrc/minddata/dataset/engine/cache/cache_client.cc

@@ -230,6 +230,9 @@ Status CacheClient::DestroyCache() {
 Status CacheClient::GetStat(CacheServiceStat *stat) {
   SharedLock lck(&mux_);
   RETURN_UNEXPECTED_IF_NULL(stat);
+  // GetStat has an external interface, so we have to make sure we have a valid connection id first
+  CHECK_FAIL_RETURN_UNEXPECTED(server_connection_id_ != 0, "GetStat called but the cache is not in use yet.");
+
   auto rq = std::make_shared<GetStatRequest>(server_connection_id_);
   RETURN_IF_NOT_OK(PushRequest(rq));
   RETURN_IF_NOT_OK(rq->Wait());

mindspore/ccsrc/minddata/dataset/engine/cache/cache_pool.cc

@@ -48,12 +48,10 @@ Status CachePool::DoServiceStop() {
   }
   sm_.reset();
 
-  value_allocator alloc(mp_);
+  // We used to free the memory allocated from each DataLocator but
-  for (auto &bl : *tree_) {
+  // since all of them are coming from NumaMemoryPool and we will
-    if (bl.ptr != nullptr) {
+  // skip this and release the whole NumaMemoryPool instead. Otherwise
-      alloc.deallocate(bl.ptr, bl.sz);
+  // release each buffer in the DataLocator one by one.
-    }
-  }
 
   tree_.reset();
   if (!root_.toString().empty()) {

tests/ut/python/cachetests/cachetest_args.sh

@@ -175,7 +175,7 @@ num_cpu=$(grep -c processor /proc/cpuinfo)
 if [ $num_cpu -lt 100 ]; then
   cmd="${CACHE_ADMIN} --start -w 101"
 else
-  cmd="${CACHE_ADMIN} --start -w ${num_cpu}+1"
+  cmd="${CACHE_ADMIN} --start -w $(($num_cpu+1))"
 fi
 CacheAdminCmd "${cmd}" 1
 HandleRcExit $? 0 0

tests/ut/python/dataset/test_cache_nomap.py

@@ -339,7 +339,7 @@ def test_cache_nomap_basic8():
          |
       TFReader
     """
-    logger.info("Test cache basic 4")
+    logger.info("Test cache basic 8")
     if "SESSION_ID" in os.environ:
         session_id = int(os.environ['SESSION_ID'])
     else:
@@ -355,7 +355,33 @@ def test_cache_nomap_basic8():
 
     logger.info("Number of data in ds1: {} ".format(num_iter))
     assert num_iter == 3
-    logger.info('test_cache_basic3 Ended.\n')
+    logger.info('test_cache_basic8 Ended.\n')
+
+
+@pytest.mark.skipif(os.environ.get('RUN_CACHE_TEST') != 'TRUE', reason="Require to bring up cache server")
+def test_cache_nomap_basic9():
+    """
+    Testing the GetStat interface for getting some info from server, but this should fail if the cache is not created
+    in a pipeline.
+    """
+
+    logger.info("Test cache nomap basic 9")
+    if "SESSION_ID" in os.environ:
+        session_id = int(os.environ['SESSION_ID'])
+    else:
+        raise RuntimeError("Testcase requires SESSION_ID environment variable")
+
+    some_cache = ds.DatasetCache(session_id=session_id, size=0, spilling=True)
+
+    # Contact the server to get the statistics, this should fail because we have not used this cache in any pipeline
+    # so there will not be any cache to get stats on.
+    with pytest.raises(RuntimeError) as e:
+        stat = some_cache.GetStat()
+        cache_sz = stat.avg_cache_sz
+        logger.info("Average row cache size: {}".format(cache_sz))
+    assert "Unexpected error" in str(e.value)
+
+    logger.info("test_cache_nomap_basic9 Ended.\n")
 
 
 @pytest.mark.skipif(os.environ.get('RUN_CACHE_TEST') != 'TRUE', reason="Require to bring up cache server")