Release host buffers when read schema is empty (#6221)

Signed-off-by: Firestarman <firestarmanllc@gmail.com>

integration_tests/src/main/python/avro_test.py

@@ -16,10 +16,9 @@
 from spark_session import with_cpu_session, with_gpu_session
 import pytest
 
-from asserts import assert_gpu_and_cpu_are_equal_collect
+from asserts import assert_gpu_and_cpu_are_equal_collect, assert_gpu_and_cpu_row_counts_equal
 from data_gen import *
 from marks import *
-from pyspark.sql.types import *
 
 if os.environ.get('INCLUDE_SPARK_AVRO_JAR', 'false') == 'false':
     pytestmark = pytest.mark.skip(reason=str("INCLUDE_SPARK_AVRO_JAR is disabled"))
@@ -137,3 +136,17 @@ def test_avro_read_with_corrupt_files(spark_tmp_path, reader_type, v1_enabled_li
     assert_gpu_and_cpu_are_equal_collect(
             lambda spark : spark.read.format("avro").load([first_dpath, second_dpath, third_dpath]),
             conf=all_confs)
+
+
+@pytest.mark.parametrize('v1_enabled_list', ["avro", ""], ids=["v1", "v2"])
+@pytest.mark.parametrize('reader_type', ['PERFILE', 'MULTITHREADED'])
+def test_read_count(spark_tmp_path, v1_enabled_list, reader_type):
+    data_path = spark_tmp_path + '/AVRO_DATA'
+    gen_avro_files([('_c0', int_gen)], data_path)
+
+    all_confs = copy_and_update(_enable_all_types_conf, {
+        'spark.rapids.sql.format.avro.reader.type': reader_type,
+        'spark.sql.sources.useV1SourceList': v1_enabled_list})
+    assert_gpu_and_cpu_row_counts_equal(
+        lambda spark: spark.read.format("avro").load(data_path),
+        conf=all_confs)

sql-plugin/src/main/scala/org/apache/spark/sql/rapids/GpuAvroScan.scala

@@ -777,6 +777,7 @@ class GpuMultiFileCloudAvroPartitionReader(
 
           val bufAndSize: Array[(HostMemoryBuffer, Long)] = if (readDataSchema.isEmpty) {
             // Overload the size to be the number of rows with null buffer
+            hostBuffers.foreach(_._1.safeClose(new Exception))
             Array((null, totalRowsNum))
           } else if (isDone) {
             // got close before finishing, return null buffer and zero size