note description: "[ Supports spawning of mulitple processes asynchronously with a synchronous queue. ]" legal: "See notice at end of class." status: "See notice at end of class."; date: "$Date$"; revision: "$Revision $" class SPAWNER inherit ANY THREAD_CONTROL export {NONE} all end create make feature -- Initialization make (a_threshold: like concurrent_threshold) -- Initialize spawner using a maximum number threshold of processes to spawn. require a_threshold_positive: a_threshold > 0 do create mutex.make create internal_running_processes.make (concurrent_threshold) create internal_unsuccessful_processes.make (0) concurrent_threshold := a_threshold reset ensure concurrent_threshold_set: concurrent_threshold = a_threshold not_exit_failurea_process: not exit_failure successful: successful end feature -- Access running: NATURAL_16 -- Number of running processes do mutex.lock Result := internal_running_processes.count.to_natural_16 mutex.unlock end running_processes: ARRAYED_LIST [PROCESS] -- List of processes running at this point in time -- Note: Due to thread-saftey a new list is returned for each call. do mutex.lock Result := internal_running_processes.twin Result.start mutex.unlock ensure result_attached: Result /= Void end unsuccessful_processes: ARRAYED_LIST [PROCESS] -- List of processes that failed to execute correctly -- Note: Due to thread-saftey a new list is returned for each call. do mutex.lock Result := internal_unsuccessful_processes.twin Result.start mutex.unlock ensure result_attached: Result /= Void end feature {NONE} -- Access concurrent_threshold: NATURAL_16 -- Maximum number of concurrent processes feature -- Status report successful: BOOLEAN -- Indiciates if the last run process was successful do mutex.lock Result := internal_unsuccessful_processes.is_empty mutex.unlock end is_running: BOOLEAN -- Determines if any processes are currently running do Result := running > 0 end feature {NONE} -- Status report is_at_threshold: BOOLEAN -- Determines if spawer is current running a number of processes that -- reaches the threshold `concurrent_threshold' note thread: safe do mutex.lock Result := running = concurrent_threshold mutex.unlock end exit_failure: BOOLEAN -- Indicates if there was a process exit failure feature {NONE} -- Helpers execution_environment: EXECUTION_ENVIRONMENT -- Access to the execution environment. once create Result ensure result_attached: Result /= Void end feature -- Basic operations reset -- Reset spawner internals after a failure require not_is_running: not is_running do exit_failure := False internal_running_processes.wipe_out internal_unsuccessful_processes.wipe_out ensure not_exit_failure: not exit_failure successful: successful end launch_process (a_process: PROCESS; a_fail_on_error: BOOLEAN) -- Launches a process. -- -- `a_process': Process to launch. -- `a_fail_on_error': True to causes a failure on a non-successful error result, False otherwise. require a_process_attached: a_process /= Void not_a_process_launched: not a_process.launched do if not exit_failure then start_process (a_process, a_fail_on_error) from until not is_at_threshold loop yield execution_environment.sleep (10) end end end wait_for_exit -- Waits for all running processes to exit do from until not is_running loop yield execution_environment.sleep (10) end end feature {NONE} -- Extension start_process (a_process: PROCESS; a_fail_on_error: BOOLEAN) -- Starts the process `a_process' and returns -- -- `a_process': Process to launch. -- `a_fail_on_error': Indicates if a failure exit code should signal a complete failure. require a_process_attached: a_process /= Void not_a_process_launched: not a_process.launched not_a_process_is_running: not a_process.is_running not_is_at_threshold: not is_at_threshold not_exit_failure: not exit_failure do a_process.set_on_exit_handler (agent remove_process (a_process, a_fail_on_error)) mutex.lock internal_running_processes.extend (a_process) mutex.unlock a_process.launch mutex.lock if not a_process.launched then remove_process (a_process, a_fail_on_error) end mutex.unlock end feature {NONE} -- Removal remove_process (a_process: PROCESS; a_fail_on_error: BOOLEAN) -- Removed the process `a_process' from the list of running processes -- Note: If `a_process' returned an error result `successful' is affected. -- -- `a_process': Process to removed from the list. -- `a_fail_on_error': Indicates if a failure exit code should signal a complete failure. require a_process_attached: a_process /= Void not_a_process_is_running: not a_process.is_running do mutex.lock internal_running_processes.start internal_running_processes.search (a_process) if not internal_running_processes.after then internal_running_processes.remove end if not a_process.launched or else a_process.exit_code /= 0 then if a_fail_on_error then exit_failure := True end internal_unsuccessful_processes.extend (a_process) end mutex.unlock end feature {NONE} -- Implementation mutex: MUTEX -- Global mutext for controlling access to `Current' feature {NONE} -- Internal implementation cache internal_unsuccessful_processes: attached ARRAYED_LIST [PROCESS] -- Cached version of `unsuccessful_processes' -- Note: Do not use directly! internal_running_processes: attached ARRAYED_LIST [PROCESS] -- Cached version of `running_processes' -- Note: Do not use directly! invariant mutex_attached: mutex /= Void running_small_enough: running <= concurrent_threshold concurrent_threshold_positive: concurrent_threshold > 0 internal_unsuccessful_processes_attached: internal_unsuccessful_processes /= Void internal_running_processes_attached: internal_running_processes /= Void ;note copyright: "Copyright (c) 1984-2007, Eiffel Software" license: "GPL version 2 (see http://www.eiffel.com/licensing/gpl.txt)" licensing_options: "http://www.eiffel.com/licensing" copying: "[ This file is part of Eiffel Software's Eiffel Development Environment. Eiffel Software's Eiffel Development Environment is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2 of the License (available at the URL listed under "license" above). Eiffel Software's Eiffel Development Environment is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Eiffel Software's Eiffel Development Environment; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA ]" source: "[ Eiffel Software 356 Storke Road, Goleta, CA 93117 USA Telephone 805-685-1006, Fax 805-685-6869 Website http://www.eiffel.com Customer support http://support.eiffel.com ]" end