Fix partial results sending in rps runner

Also made some improvements:
* removed class WorkerProcess
* properly calculated times_per_worker value
* properly calculated rps
* join threads once they finished

Change-Id: I15b604af6f5ec145e6a67265fba6c6443056137f

rally/benchmark/runners/rps.py

@@ -19,9 +19,67 @@
 
 from rally.benchmark.runners import base
 from rally import consts
+from rally.openstack.common import log as logging
 from rally import utils as rutils
 
 
+LOG = logging.getLogger(__name__)
+SEND_RESULT_DELAY = 1
+
+
+def worker_process(rps, times, queue, scenario_context, timeout,
+                   worker_id, cls, method_name, args):
+    """Start scenario within threads.
+
+    Spawn N threads per second. Each thread runs scenario once, and appends
+    result to queue.
+
+    :param rps: runs per second
+    :param times: number of threads to be run
+    :param queue: queue object to append results
+    :param scenario_context: scenario context object
+    :param timeout: timeout operation
+    :param worker_id: id of worker process
+    :param cls: scenario class
+    :param method_name: scenario method name
+    :param args: scenario args
+    """
+
+    def worker_thread(args):
+        queue.put(base._run_scenario_once(args))
+
+    pool = []
+    i = 0
+    start = time.time()
+    sleep = 1.0 / rps
+
+    while times > i:
+        i += 1
+        scenario_args = (("%d:%d" % (worker_id, i), cls, method_name,
+                         scenario_context, args),)
+        thread = threading.Thread(target=worker_thread,
+                                  args=scenario_args)
+        thread.start()
+        pool.append(thread)
+
+        LOG.debug("Worker: %s rps: %s (requested rps: %s)" % (
+                  worker_id, i / (time.time() - start), rps))
+
+        # try to join latest thread(s) until it finished, or until time to
+        # start new thread
+        while i / (time.time() - start) > rps:
+            if pool:
+                pool[0].join(sleep)
+                if not pool[0].isAlive():
+                    pool.pop(0)
+            else:
+                time.sleep(sleep)
+
+    while pool:
+        thr = pool.pop(0)
+        thr.join()
+
+
 class RPSScenarioRunner(base.ScenarioRunner):
     """Scenario runner that does the job with with specified frequency.
 
@@ -59,72 +117,36 @@ class RPSScenarioRunner(base.ScenarioRunner):
 
     def _run_scenario(self, cls, method_name, context, args):
         times = self.config["times"]
-        rps = self.config["rps"]
         timeout = self.config.get("timeout", 600)
         cpu_count = multiprocessing.cpu_count()
+        processes2start = cpu_count if times >= cpu_count else times
+        rps_per_worker = float(self.config["rps"]) / processes2start
 
         queue = multiprocessing.Queue()
-        addition_args = args
-
-        class WorkerProcess(multiprocessing.Process):
-
-            def __init__(self, rps, times, queue, scenario_context, timeout,
-                         process_id, args):
-                self.rps = rps
-                self.times = times
-                self.timeout = timeout
-                self.pool = []
-                self.scenario_context = scenario_context
-                self.id = process_id
-                self.args = args
-                self.queue = queue
-                super(WorkerProcess, self).__init__()
-
-            def _th_worker(self, args):
-                result = base._run_scenario_once(args)
-                self.queue.put(result)
-
-            def run(self):
-                for i in range(self.times):
-                    scenario_args = (("%d:%d" % (self.id, i), cls, method_name,
-                                     self.scenario_context, self.args),)
-                    thread = threading.Thread(target=self._th_worker,
-                                              args=scenario_args)
-                    thread.start()
-                    self.pool.append(thread)
-                    time.sleep(1.0 / rps)
-
-                while len(self.pool):
-                    thr = self.pool.pop()
-                    thr.join(self.timeout)
 
         process_pool = []
         scenario_context = base._get_scenario_context(context)
 
-        if times <= cpu_count:
-            processes2start = times
-        else:
-            processes2start = cpu_count
+        times_per_worker, rest = divmod(times, processes2start)
 
         for i in range(processes2start):
-            process = WorkerProcess(rps / float(processes2start),
-                                    times / processes2start,
-                                    queue, scenario_context, timeout,
-                                    i, addition_args)
+            times = times_per_worker + int(rest > 0)
+            rest -= 1
+            worker_args = (rps_per_worker, times, queue, scenario_context,
+                           timeout, i, cls, method_name, args)
+            process = multiprocessing.Process(target=worker_process,
+                                              args=worker_args)
             process.start()
             process_pool.append(process)
 
-        while len(process_pool):
+        while process_pool:
             for process in process_pool:
+                process.join(SEND_RESULT_DELAY)
                 if not process.is_alive():
-                    process.join(timeout)
+                    process.join()
                     process_pool.remove(process)
-            if not queue.empty():
-                self._send_result(queue.get(timeout=timeout))
-            time.sleep(1.0 / rps)
 
-        while not queue.empty():
-            result = queue.get(timeout=timeout)
-            self._send_result(result)
+            while not queue.empty():
+                self._send_result(queue.get())
 
         queue.close()