do not randomize the seq/rand ratio

bench.py

@@ -520,16 +520,16 @@ class Reader(object):
         return objects_count, bytes_read
 
 
-def reader(args, image):
+def reader(args, image, pattern):
     reader = Reader(args, image)
     reader.init()
-    if random.random() * 100 < args.rand_ratio:
+    if pattern == "rand":
         (objects_count, bytes_read, too_long) = reader.read_rand()
     else:
         too_long = None
         (objects_count, bytes_read) = reader.read_seq()
     reader.uninit()
-    return (image, objects_count, bytes_read, too_long)
+    return (image, objects_count, bytes_read, too_long, pattern)
 
 
 class Bench(object):
@@ -589,9 +589,12 @@ class Bench(object):
 
             logging.warning("Bench.ro_loop: running")
             self.readers = set()
+            pending_readers = ["seq"] * (self.args.ro_workers - self.args.rand_ratio) + [
+                "rand"
+            ] * self.args.rand_ratio
 
-            def create_reader():
-                return loop.run_in_executor(executor, reader, self.args, random.choice(self.images))
+            def create_reader(pattern):
+                return loop.run_in_executor(executor, reader, self.args, random.choice(self.images), pattern)
 
             while not finished.is_set():
 
@@ -599,13 +602,15 @@ class Bench(object):
                     await asyncio.sleep(1)
                     continue
 
-                while len(self.readers) < self.args.ro_workers:
-                    self.readers.add(create_reader())
+                for pattern in pending_readers:
+                    self.readers.add(create_reader(pattern))
+                pending_readers = []
 
                 logging.debug(f"Bench.ro_loop: waiting on {len(self.readers)} readers")
                 done, self.readers = await asyncio.wait(self.readers, return_when=asyncio.FIRST_COMPLETED)
                 for task in done:
-                    (image, objects, size, too_long) = task.result()
+                    (image, objects, size, too_long, pattern) = task.result()
+                    pending_readers.append(pattern)
                     logging.debug(f"Bench.ro_loop: {image} {objects} objects, {size} bytes")
                     self.stats["object_read_count"] += objects
                     self.stats["bytes_read"] += size