New test script for #709 consumes memory by reading a file over and o…

…ver.

utils/memory_consumer2.py

@@ -0,0 +1,55 @@
+from argparse import ArgumentParser, ArgumentDefaultsHelpFormatter, FileType
+
+from datetime import datetime, timedelta
+
+
+def parse_args():
+    parser = ArgumentParser(description='Consume memory, and keep it active.',
+                            formatter_class=ArgumentDefaultsHelpFormatter)
+    parser.add_argument('-t',
+                        '--time',
+                        type=int,
+                        help='time in seconds to run')
+    parser.add_argument('source',
+                        type=FileType('rb'),
+                        default='/dev/urandom',
+                        nargs='?',
+                        help='source file to read data from')
+    parser.add_argument('size',
+                        type=int,
+                        default=1000,
+                        nargs='?',
+                        help='size of memory to hold, in MB')
+    return parser.parse_args()
+
+
+def read_chunk(source):
+    read_size = 1024*1024
+    chunk = ''
+    while read_size:
+        piece = source.read(read_size)
+        if not piece:
+            source.seek(0)
+            piece = '!'
+        chunk += piece
+        read_size -= len(piece)
+    return chunk
+
+
+def main():
+    args = parse_args()
+    if args.time is None:
+        end_time = None
+    else:
+        end_time = datetime.now() + timedelta(seconds=args.time)
+    chunks = []
+    allocated_count = 0
+    while end_time is None or datetime.now() < end_time:
+        while len(chunks) > args.size:
+            chunks.pop(0)
+        chunks.append(read_chunk(args.source))
+        allocated_count += 1
+    print('Allocated {}; now holding {}.'.format(allocated_count, len(chunks)))
+
+
+main()