ceph/src/common/common_init.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) 2009-2011 New Dream Network
   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 #ifndef CEPH_COMMON_INIT_H
  16 #define CEPH_COMMON_INIT_H
  17
  18 #include <deque>
  19
  20 #include "common/code_environment.h"
  21
  22 class CephContext;
  23 class CephInitParameters;
  24
  25 enum common_init_flags_t {
  26   // Set up defaults that make sense for an unprivileged deamon
  27   CINIT_FLAG_UNPRIVILEGED_DAEMON_DEFAULTS = 0x1,
  28
  29   // By default, don't read a configuration file
  30   CINIT_FLAG_NO_DEFAULT_CONFIG_FILE = 0x2,
  31
  32   // Don't close stderr (in daemonize)
  33   CINIT_FLAG_NO_CLOSE_STDERR = 0x4,
  34
  35   // don't do anything daemonish, like create /var/run/ceph, or print a banner
  36   CINIT_FLAG_NO_DAEMON_ACTIONS = 0x8,
  37
  38   // don't drop privileges
  39   CINIT_FLAG_DEFER_DROP_PRIVILEGES = 0x10,
  40 };
  41
  42 /*
  43  * NOTE: If you are writing a Ceph daemon, ignore this function and call
  44  * global_init instead. It will call common_preinit for you.
  45  *
  46  * common_preinit creates the CephContext.
  47  *
  48  * After this function gives you a CephContext, you need to set up the
  49  * Ceph configuration, which lives inside the CephContext as md_config_t.
  50  * The initial settings are not very useful because they do not reflect what
  51  * the user asked for.
  52  *
  53  * This is usually done by something like this:
  54  * cct->_conf->parse_env();
  55  * cct->_conf->apply_changes();
  56  *
  57  * Your library may also supply functions to read a configuration file.
  58  */
  59 CephContext *common_preinit(const CephInitParameters &iparams,
  60                             enum code_environment_t code_env, int flags);
  61
  62 /* Print out some parse errors. */
  63 void complain_about_parse_errors(CephContext *cct,
  64                                  std::deque<std::string> *parse_errors);
  65
  66 /* This function is called after you have done your last
  67  * fork. When you make this call, the system will initialize everything that
  68  * cannot be initialized before a fork.
  69  *
  70  * This includes things like starting threads, initializing libraries that
  71  * can't handle forking, and so forth.
  72  *
  73  * If you are writing a Ceph library, you can call this pretty much any time.
  74  * We do not allow our library users to fork and continue using the Ceph
  75  * libraries. The most obvious reason for this is that the threads started by
  76  * the Ceph libraries would be destroyed by a fork().
  77  */
  78 void common_init_finish(CephContext *cct);
  79
  80 #endif