Refactor for re-use

src/calibre/utils/ipc/pool.py

@@ -49,6 +49,32 @@ if iswindows:
             from calibre.utils.ipc.launch import windows_null_file
             worker_kwargs['stdout'] = worker_kwargs['stderr'] = windows_null_file
 
+def get_stdout(process):
+    import time
+    while process.poll() is None:
+        try:
+            raw = process.stdout.read(1)
+            if raw:
+                try:
+                    sys.stdout.write(raw)
+                except EnvironmentError:
+                    pass
+            else:
+                time.sleep(0.1)
+        except (EOFError, EnvironmentError):
+            break
+
+def start_worker(code, name=''):
+    from calibre.utils.ipc.simple_worker import start_pipe_worker
+    if name:
+        name = '-' + name
+    p = start_pipe_worker(code, **worker_kwargs)
+    if get_stdout_from_child:
+        t = Thread(target=get_stdout, name='PoolWorkerGetStdout' + name, args=(p,))
+        t.daemon = True
+        t.start()
+    return p
+
 class Failure(Exception):
 
     def __init__(self, tf):
@@ -63,10 +89,6 @@ class Worker(object):
         self.process, self.conn = p, conn
         self.events = events
         self.name = name or ''
-        if get_stdout_from_child:
-            t = Thread(target=self.get_stdout, name='PoolWorkerGetOutput-'+self.name)
-            t.daemon = True
-            t.start()
 
     def __call__(self, job):
         eintr_retry_call(self.conn.send_bytes, cPickle.dumps(job, -1))
@@ -89,21 +111,6 @@ class Worker(object):
     def set_common_data(self, data):
         eintr_retry_call(self.conn.send_bytes, data)
 
-    def get_stdout(self):
-        import time
-        while self.process.poll() is None:
-            try:
-                raw = self.process.stdout.read(1)
-                if raw:
-                    try:
-                        sys.stdout.write(raw)
-                    except EnvironmentError:
-                        pass
-                else:
-                    time.sleep(0.1)
-            except (EOFError, EnvironmentError):
-                break
-
 
 class Pool(Thread):
 
@@ -175,9 +182,7 @@ class Pool(Thread):
         self.shutdown_workers(wait_time=wait_time)
 
     def create_worker(self):
-        from calibre.utils.ipc.simple_worker import start_pipe_worker
+        p = start_worker('from {0} import run_main, {1}; run_main({1})'.format(self.__class__.__module__, 'worker_main'))
-        p = start_pipe_worker(
-            'from {0} import run_main, {1}; run_main({1})'.format(self.__class__.__module__, 'worker_main'), **worker_kwargs)
         sys.stdout.flush()
         eintr_retry_call(p.stdin.write, self.worker_data)
         p.stdin.flush(), p.stdin.close()