Class Mpi4py_processor

The mpi4py multi-processor class.

Instance Methods

__init__(self, processor_size, callback)
Initialise the mpi4py processor.

_broadcast_command(self, command)

_ditch_all_results(self)

abort(self)
Shutdown the multi processor in exceptional conditions - designed for overriding.

assert_on_master(self)
Make sure that this is the master processor and not a slave.

exit(self, status=0)
Exit the mpi4py processor with the given status.

str get_intro_string(self)
Return the string to append to the end of the relax introduction string.

str get_name(self)
Get the name of the current processor - an abstract method.

master_queue_command(self, command, dest)
Slave to master processor data transfer - send the result command from the slave.

Result_command instance master_receive_result(self)
Slave to master processor data transfer - receive the result command from the slave.

int rank(self)
Get the rank of this processor - an abstract method.

return_result_command(self, result_object)

run(self)
Run the processor - an abstract method.

slave_receive_commands(self)

Inherited from multi_processor_base.Multi_processor: add_to_queue, chunk_queue, on_master, on_slave, post_run, pre_run, process_result, return_object

Inherited from processor.Processor: fetch_data, get_stdio_pre_strings, get_time_delta, processor_size, rank_format_string, rank_format_string_width, run_command_globally, run_command_queue, run_queue, send_data_to_slaves, stdio_capture, stdio_restore

Inherited from object: __delattr__, __format__, __getattribute__, __hash__, __new__, __reduce__, __reduce_ex__, __repr__, __setattr__, __sizeof__, __str__, __subclasshook__

Instance Variables

Inherited from processor.Processor: NULL_RESULT, callback, data_store, grainyness, threaded_result_processing

Inherited from processor.Processor (private): _processor_size

Properties

Inherited from object: __class__

Method Details

__init__(self, processor_size, callback)
(Constructor)

Initialise the mpi4py processor.

Parameters:

• processor_size - The requested number of __slave__processors, if the number of processors is set by the environment (e.g. in the case of MPI via mpiexec -np <n-processors> on the command line the processor is free free to ignore this value. The default value from the command line is -1, and subclasses on receiving this value either raise and exception or determine the correct number of slaves to create (e.g. on a multi-cored machine using a threaded implementation the correct number of slaves would be equal to the number of cores available).
• callback - The application callback which allows the host application to start its main loop and handle exceptions from the processor.

Overrides: object.__init__

abort(self)

Shutdown the multi processor in exceptional conditions - designed for overriding.

This method is called after an exception from the master or slave has been raised and processed and is responsible for the shutdown of the multi processor fabric and terminating the application. The functions should be called as the last thing that Application_callback.handle_exception does.

As an example of the methods use see Mpi4py_processor.abort which calls MPI.COMM_WORLD.Abort() to cleanly shutdown the mpi framework and remove dangling processes.

The default action is to call the special self.exit() method.

Overrides: processor.Processor.abort

(inherited documentation)

assert_on_master(self)

Make sure that this is the master processor and not a slave.

Raises:

• Exception - If not on the master processor.

Overrides: processor.Processor.assert_on_master

exit(self, status=0)

Exit the mpi4py processor with the given status.

Parameters:

• status (int) - The program exit status.

Overrides: processor.Processor.exit

get_intro_string(self)

Return the string to append to the end of the relax introduction string.

Returns: str

The string describing this Processor fabric.

Overrides: processor.Processor.get_intro_string

get_name(self)

Get the name of the current processor - an abstract method.

The string should identify the current master or slave processor uniquely but is purely for information and debugging. For example the mpi implementation uses the string <host-name>-<process-id> whereas the thread implementation uses the id of the current thread as provided by python.

Returns: str

The processor identifier.

Overrides: processor.Processor.get_name

(inherited documentation)

master_queue_command(self, command, dest)

Slave to master processor data transfer - send the result command from the slave.

Parameters:

• command (Results_command instance) - The results command to send to the master.
• dest (int) - The destination processor's rank.

Overrides: processor.Processor.master_queue_command

master_receive_result(self)

Slave to master processor data transfer - receive the result command from the slave.

This is invoked by the master processor.

Returns: Result_command instance

The result command sent by the slave.

Overrides: processor.Processor.master_receive_result

rank(self)

Get the rank of this processor - an abstract method.

The rank of the processor should be a number between 0 and n where n is the number of slave processors, the rank of 0 is reserved for the master processor.

Returns: int

The rank of the processor.

Overrides: processor.Processor.rank

(inherited documentation)

return_result_command(self, result_object)

Overrides: multi_processor_base.Multi_processor.return_result_command

run(self)

Run the processor - an abstract method.

This function runs the processor main loop and is called after all processor setup has been completed. It does remote execution setup and teardown (via self.pre_run() and self.post_run()) round either side of a call to Application_callback.init_master.

Overrides: processor.Processor.run

(inherited documentation)

slave_receive_commands(self)

Overrides: multi_processor_base.Multi_processor.slave_receive_commands