ceph/src/seastar/include/seastar/core/app-template.hh

   1 /*
   2  * This file is open source software, licensed to you under the terms
   3  * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
   4  * distributed with this work for additional information regarding copyright
   5  * ownership.  You may not use this file except in compliance with the License.
   6  *
   7  * You may obtain a copy of the License at
   8  *
   9  *   http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing,
  12  * software distributed under the License is distributed on an
  13  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  14  * KIND, either express or implied.  See the License for the
  15  * specific language governing permissions and limitations
  16  * under the License.
  17  */
  18 /*
  19  * Copyright (C) 2014 Cloudius Systems, Ltd.
  20  */
  21 #pragma once
  22
  23 #include <boost/program_options.hpp>
  24 #include <functional>
  25 #include <seastar/core/future.hh>
  26 #include <seastar/core/smp.hh>
  27 #include <seastar/core/sstring.hh>
  28 #include <seastar/util/program-options.hh>
  29 #include <seastar/core/metrics_api.hh>
  30 #include <seastar/core/scollectd.hh>
  31 #include <seastar/util/log-cli.hh>
  32 #include <chrono>
  33
  34 namespace seastar {
  35
  36 namespace alien {
  37
  38 class instance;
  39
  40 }
  41
  42 class app_template {
  43 public:
  44     struct config {
  45         /// The name of the application.
  46         ///
  47         /// Will be used in the --help output to distinguish command line args
  48         /// registered by the application, as opposed to those registered by
  49         /// seastar and its subsystems.
  50         sstring name = "App";
  51         /// The description of the application.
  52         ///
  53         /// Will be printed on the top of the --help output. Lines should be
  54         /// hard-wrapped for 80 chars.
  55         sstring description = "";
  56         std::chrono::duration<double> default_task_quota = std::chrono::microseconds(500);
  57         /// \brief Handle SIGINT/SIGTERM by calling reactor::stop()
  58         ///
  59         /// When true, Seastar will set up signal handlers for SIGINT/SIGTERM that call
  60         /// reactor::stop(). The reactor will then execute callbacks installed by
  61         /// reactor::at_exit().
  62         ///
  63         /// When false, Seastar will not set up signal handlers for SIGINT/SIGTERM
  64         /// automatically. The default behavior (terminate the program) will be kept.
  65         /// You can adjust the behavior of SIGINT/SIGTERM by installing signal handlers
  66         /// via reactor::handle_signal().
  67         bool auto_handle_sigint_sigterm = true;
  68         /// Specifies the default value for linux-aio I/O control blocks. This translates
  69         /// to the maximum number of sockets the shard can handle.
  70         unsigned max_networking_aio_io_control_blocks = 10000;
  71         config() {}
  72     };
  73
  74     /// Seastar configuration options
  75     struct seastar_options : public program_options::option_group {
  76         /// The name of the application.
  77         ///
  78         /// Will be used in the --help output to distinguish command line args
  79         /// registered by the application, as opposed to those registered by
  80         /// seastar and its subsystems.
  81         sstring name = "App";
  82         /// The description of the application.
  83         ///
  84         /// Will be printed on the top of the --help output. Lines should be
  85         /// hard-wrapped for 80 chars.
  86         sstring description = "";
  87         /// \brief Handle SIGINT/SIGTERM by calling reactor::stop()
  88         ///
  89         /// When true, Seastar will set up signal handlers for SIGINT/SIGTERM that call
  90         /// reactor::stop(). The reactor will then execute callbacks installed by
  91         /// reactor::at_exit().
  92         ///
  93         /// When false, Seastar will not set up signal handlers for SIGINT/SIGTERM
  94         /// automatically. The default behavior (terminate the program) will be kept.
  95         /// You can adjust the behavior of SIGINT/SIGTERM by installing signal handlers
  96         /// via reactor::handle_signal().
  97         bool auto_handle_sigint_sigterm = true;
  98         /// Configuration options for the reactor.
  99         reactor_options reactor_opts;
 100         /// Configuration for the metrics sub-system.
 101         metrics::options metrics_opts;
 102         /// Configuration options for the smp aspect of seastar.
 103         smp_options smp_opts;
 104         /// Configuration for the scollectd sub-system.
 105         scollectd::options scollectd_opts;
 106         /// Configuration for the logging sub-system.
 107         log_cli::options log_opts;
 108
 109         seastar_options();
 110     };
 111
 112     using configuration_reader = std::function<void (boost::program_options::variables_map&)>;
 113 private:
 114     // unique_ptr to avoid pulling in alien.hh.
 115     std::unique_ptr<alien::instance> _alien;
 116     // reactor destruction is asynchronous, so we must let the last reactor
 117     // destroy the smp instance
 118     std::shared_ptr<smp> _smp;
 119     seastar_options _opts;
 120     boost::program_options::options_description _app_opts;
 121     boost::program_options::options_description _seastar_opts;
 122     boost::program_options::options_description _opts_conf_file;
 123     boost::program_options::positional_options_description _pos_opts;
 124     std::optional<boost::program_options::variables_map> _configuration;
 125     configuration_reader _conf_reader;
 126
 127     configuration_reader get_default_configuration_reader();
 128 public:
 129     struct positional_option {
 130         const char* name;
 131         const boost::program_options::value_semantic* value_semantic;
 132         const char* help;
 133         int max_count;
 134     };
 135 public:
 136     explicit app_template(seastar_options opts);
 137     explicit app_template(config cfg = config());
 138     ~app_template();
 139
 140     const seastar_options& options() const;
 141
 142     boost::program_options::options_description& get_options_description();
 143     boost::program_options::options_description& get_conf_file_options_description();
 144     boost::program_options::options_description_easy_init add_options();
 145     void add_positional_options(std::initializer_list<positional_option> options);
 146     boost::program_options::variables_map& configuration();
 147     int run_deprecated(int ac, char ** av, std::function<void ()>&& func) noexcept;
 148
 149     void set_configuration_reader(configuration_reader conf_reader);
 150
 151     /// Obtains an alien::instance object that can be used to send messages
 152     /// to Seastar shards from non-Seastar threads.
 153     alien::instance& alien() { return *_alien; }
 154
 155     // Runs given function and terminates the application when the future it
 156     // returns resolves. The value with which the future resolves will be
 157     // returned by this function.
 158     int run(int ac, char ** av, std::function<future<int> ()>&& func) noexcept;
 159
 160     // Like run() which takes std::function<future<int>()>, but returns
 161     // with exit code 0 when the future returned by func resolves
 162     // successfully.
 163     int run(int ac, char ** av, std::function<future<> ()>&& func) noexcept;
 164 };
 165
 166 }