ceph/src/mgr/PyModuleRunner.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2016 John Spray <john.spray@redhat.com>
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  */
  13
  14
  15 #pragma once
  16
  17 #include "common/Thread.h"
  18 #include "common/LogClient.h"
  19 #include "mgr/Gil.h"
  20
  21 /**
  22  * Implement the pattern of calling serve() on a module in a thread,
  23  * until shutdown() is called.
  24  */
  25 class PyModuleRunner
  26 {
  27 protected:
  28   const std::string module_name;
  29
  30   // Passed in by whoever loaded our python module and looked up
  31   // the symbols in it.
  32   PyObject *pClass = nullptr;
  33
  34   // Passed in by whoever created our subinterpreter for us
  35   SafeThreadState pMyThreadState = nullptr;
  36
  37   // Populated when we construct our instance of pClass in load()
  38   PyObject *pClassInstance = nullptr;
  39
  40   LogChannelRef clog;
  41
  42   class PyModuleRunnerThread : public Thread
  43   {
  44     PyModuleRunner *mod;
  45
  46   public:
  47     PyModuleRunnerThread(PyModuleRunner *mod_)
  48       : mod(mod_) {}
  49
  50     void *entry() override;
  51   };
  52
  53 public:
  54   int serve();
  55   void shutdown();
  56   void log(int level, const std::string &record);
  57
  58   PyModuleRunner(
  59       const std::string &module_name_,
  60       PyObject *pClass_,
  61       const SafeThreadState &pMyThreadState_,
  62       LogChannelRef clog_)
  63     :
  64       module_name(module_name_),
  65       pClass(pClass_), pMyThreadState(pMyThreadState_),
  66       clog(clog_),
  67       thread(this)
  68   {
  69     assert(pClass != nullptr);
  70     assert(pMyThreadState.ts != nullptr);
  71     assert(!module_name.empty());
  72   }
  73
  74   ~PyModuleRunner();
  75
  76   PyModuleRunnerThread thread;
  77
  78   std::string const &get_name() const { return module_name; }
  79 };
  80
  81