This class is capable of spawning Ruby on Rails application instances. Spawning a Ruby on Rails application is usually slow. But SpawnManager will preload and cache Ruby on Rails frameworks, as well as application code, so subsequent spawns will be very fast.
Internally, SpawnManager uses FrameworkSpawner to preload and cache Ruby on Rails frameworks. FrameworkSpawner, in turn, uses ApplicationSpawner to preload and cache application code.
Note: SpawnManager may only be started synchronously with AbstractServer#start_synchronously. Starting asynchronously has not been tested. Don‘t forget to call cleanup after the server‘s main loop has finished.
| DEFAULT_INPUT_FD | = | 3 |
| FRAMEWORK_SPAWNER_MAX_IDLE_TIME | = | 30 * 60 |
| APP_SPAWNER_MAX_IDLE_TIME | = | FrameworkSpawner::APP_SPAWNER_MAX_IDLE_TIME |
| SPAWNER_CLEAN_INTERVAL | = | [FRAMEWORK_SPAWNER_MAX_IDLE_TIME, APP_SPAWNER_MAX_IDLE_TIME].min + 5 |
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# File lib/passenger/spawn_manager.rb, line 48
48: def initialize
49: super()
50: @spawners = {}
51: @lock = Mutex.new
52: @cond = ConditionVariable.new
53: @cleaner_thread = Thread.new do
54: cleaner_thread_main
55: end
56: define_message_handler(:spawn_application, :handle_spawn_application)
57: define_message_handler(:reload, :handle_reload)
58: define_signal_handler('SIGHUP', :reload)
59: end
Cleanup resources. Should be called when this SpawnManager is no longer needed.
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# File lib/passenger/spawn_manager.rb, line 160
160: def cleanup
161: @lock.synchronize do
162: @cond.signal
163: end
164: @cleaner_thread.join
165: @lock.synchronize do
166: @spawners.each_value do |spawner|
167: spawner.stop
168: end
169: @spawners.clear
170: end
171: end
Remove the cached application instances at the given application root. If nil is specified as application root, then all cached application instances will be removed, no matter the application root.
Long description: Application code might be cached in memory. But once it a while, it will be necessary to reload the code for an application, such as after deploying a new version of the application. This method makes sure that any cached application code is removed, so that the next time an application instance is spawned, the application code will be freshly loaded into memory.
Raises AbstractServer::SpawnError if something went wrong.
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# File lib/passenger/spawn_manager.rb, line 133
133: def reload(app_root = nil)
134: if app_root
135: begin
136: app_root = normalize_path(app_root)
137: rescue ArgumentError
138: end
139: end
140: @lock.synchronize do
141: if app_root
142: # Delete associated ApplicationSpawner.
143: key = "app:#{app_root}"
144: spawner = @spawners[key]
145: if spawner
146: spawner.stop
147: @spawners.delete(key)
148: end
149: end
150: @spawners.each_value do |spawner|
151: # Reload FrameworkSpawners.
152: if spawner.respond_to?(:reload)
153: spawner.reload(app_root)
154: end
155: end
156: end
157: end
Spawn a RoR application When successful, an Application object will be returned, which represents the spawned RoR application.
See ApplicationSpawner.new for an explanation of the lower_privilege and lowest_user parameters.
SpawnManager will internally cache the code of applications, in order to speed up future spawning attempts. This implies that, if you‘ve changed the application‘s code, you must do one of these things:
- Restart this SpawnManager by calling AbstractServer#stop, then AbstractServer#start.
- Reload the application by calling reload with the correct app_root argument.
Raises:
- ArgumentError: app_root doesn‘t appear to be a valid Ruby on Rails application root.
- VersionNotFound: The Ruby on Rails framework version that the given application requires is not installed.
- AbstractServer::ServerError: One of the server processes exited unexpectedly.
- FrameworkInitError: The Ruby on Rails framework that the application requires could not be loaded.
- AppInitError: The application raised an exception or called exit() during startup.
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# File lib/passenger/spawn_manager.rb, line 80
80: def spawn_application(app_root, lower_privilege = true, lowest_user = "nobody")
81: framework_version = Application.detect_framework_version(app_root)
82: if framework_version == :vendor
83: vendor_path = normalize_path("#{app_root}/vendor/rails")
84: key = "vendor:#{vendor_path}"
85: create_spawner = proc do
86: FrameworkSpawner.new(:vendor => vendor_path)
87: end
88: elsif framework_version.nil?
89: app_root = normalize_path(app_root)
90: key = "app:#{app_root}"
91: create_spawner = proc do
92: ApplicationSpawner.new(app_root, lower_privilege, lowest_user)
93: end
94: else
95: key = "version:#{framework_version}"
96: create_spawner = proc do
97: FrameworkSpawner.new(:version => framework_version)
98: end
99: end
100:
101: spawner = nil
102: @lock.synchronize do
103: spawner = @spawners[key]
104: if !spawner
105: spawner = create_spawner.call
106: spawner.start
107: @spawners[key] = spawner
108: end
109: end
110:
111: spawner.time = Time.now
112: if spawner.is_a?(FrameworkSpawner)
113: return spawner.spawn_application(app_root, lower_privilege,
114: lowest_user)
115: else
116: return spawner.spawn_application
117: end
118: end