gemseo / core

parallel_execution module

Parallel execution of disciplines and functions using multiprocessing.

class gemseo.core.parallel_execution.DiscParallelExecution(workers, n_processes=2, use_threading=False, wait_time_between_fork=0.0, exceptions_to_re_raise=None)[source]

Bases: ParallelExecution

Execute disciplines in parallel.

Parameters:

  • workers (ParallelExecutionWorkerType) – The objects that perform the tasks. Either pass one worker, and it will be forked in multiprocessing. Or, when using multithreading or different workers, pass one worker per input data.

  • n_processes (int) –

    The maximum simultaneous number of threads, if use_threading is True, or processes otherwise, used to parallelize the execution.

    By default it is set to 2.

  • use_threading (bool) –

    If True, use threads instead of processes to parallelize the execution. Multiprocessing will copy (serialize) all the disciplines, while threading will share all the memory. This is important to note if you want to execute the same discipline multiple times, in which case you shall use multiprocessing.

    By default it is set to False.

  • wait_time_between_fork (float) –

    The time to wait between two forks of the process/thread.

    By default it is set to 0.0.

  • exceptions_to_re_raise (tuple[type[Exception]] | None) – The exceptions that should be raised again when caught inside a worker. If None, all exceptions coming from workers are caught and the execution is allowed to continue.

Raises:

ValueError – If there are duplicated workers in workers when using multithreading.

execute(input_values, exec_callback=None, task_submitted_callback=None)

Execute all the processes.

Parameters:

  • input_values (Sequence[ndarray] | ndarray) – The input values.

  • exec_callback (Callable[[int, Any], Any] | None) – A callback function called with the pair (index, outputs) as arguments when an item is retrieved from the processing. Index is the associated index in input_values of the input used to compute the outputs. If None, no function is called.

  • task_submitted_callback (Callable | None) – A callback function called when all the tasks are submitted, but not done yet. If None, no function is called.

Returns:

The computed outputs.

Raises:

TypeError – If the exec_callback is not callable. If the task_submitted_callback is not callable.

Return type:

dict[int, Any]

Warning

This class relies on multiprocessing features, it is therefore necessary to protect its execution with an if __name__ == '__main__': statement when working on Windows.

N_CPUS = 2
input_values: ndarray | None

The input values to be passed to the workers.

n_processes: int

The maximum simultaneous number of threads or processes.

use_threading: bool

Whether to use threads instead of processes to parallelize the execution.

wait_time_between_fork: float

The time to wait between two forks of the process/thread.

workers: ParallelExecutionWorkerType

The objects that perform the tasks.

class gemseo.core.parallel_execution.DiscParallelLinearization(workers, n_processes=2, use_threading=False, wait_time_between_fork=0.0, exceptions_to_re_raise=None)[source]

Bases: ParallelExecution

Linearize disciplines in parallel.

Parameters:

  • workers (ParallelExecutionWorkerType) – The objects that perform the tasks. Either pass one worker, and it will be forked in multiprocessing. Or, when using multithreading or different workers, pass one worker per input data.

  • n_processes (int) –

    The maximum simultaneous number of threads, if use_threading is True, or processes otherwise, used to parallelize the execution.

    By default it is set to 2.

  • use_threading (bool) –

    If True, use threads instead of processes to parallelize the execution. Multiprocessing will copy (serialize) all the disciplines, while threading will share all the memory. This is important to note if you want to execute the same discipline multiple times, in which case you shall use multiprocessing.

    By default it is set to False.

  • wait_time_between_fork (float) –

    The time to wait between two forks of the process/thread.

    By default it is set to 0.0.

  • exceptions_to_re_raise (tuple[type[Exception]] | None) – The exceptions that should be raised again when caught inside a worker. If None, all exceptions coming from workers are caught and the execution is allowed to continue.

Raises:

ValueError – If there are duplicated workers in workers when using multithreading.

execute(input_values, exec_callback=None, task_submitted_callback=None)

Execute all the processes.

Parameters:

  • input_values (Sequence[ndarray] | ndarray) – The input values.

  • exec_callback (Callable[[int, Any], Any] | None) – A callback function called with the pair (index, outputs) as arguments when an item is retrieved from the processing. Index is the associated index in input_values of the input used to compute the outputs. If None, no function is called.

  • task_submitted_callback (Callable | None) – A callback function called when all the tasks are submitted, but not done yet. If None, no function is called.

Returns:

The computed outputs.

Raises:

TypeError – If the exec_callback is not callable. If the task_submitted_callback is not callable.

Return type:

dict[int, Any]

Warning

This class relies on multiprocessing features, it is therefore necessary to protect its execution with an if __name__ == '__main__': statement when working on Windows.

N_CPUS = 2
input_values: ndarray | None

The input values to be passed to the workers.

n_processes: int

The maximum simultaneous number of threads or processes.

use_threading: bool

Whether to use threads instead of processes to parallelize the execution.

wait_time_between_fork: float

The time to wait between two forks of the process/thread.

workers: ParallelExecutionWorkerType

The objects that perform the tasks.

class gemseo.core.parallel_execution.ParallelExecution(workers, n_processes=2, use_threading=False, wait_time_between_fork=0.0, exceptions_to_re_raise=None)[source]

Bases: object

Perform a parallel execution of tasks on input values.

Input values must be a list of independent pointers.

Parameters:

  • workers (ParallelExecutionWorkerType) – The objects that perform the tasks. Either pass one worker, and it will be forked in multiprocessing. Or, when using multithreading or different workers, pass one worker per input data.

  • n_processes (int) –

    The maximum simultaneous number of threads, if use_threading is True, or processes otherwise, used to parallelize the execution.

    By default it is set to 2.

  • use_threading (bool) –

    If True, use threads instead of processes to parallelize the execution. Multiprocessing will copy (serialize) all the disciplines, while threading will share all the memory. This is important to note if you want to execute the same discipline multiple times, in which case you shall use multiprocessing.

    By default it is set to False.

  • wait_time_between_fork (float) –

    The time to wait between two forks of the process/thread.

    By default it is set to 0.0.

  • exceptions_to_re_raise (tuple[type[Exception]] | None) – The exceptions that should be raised again when caught inside a worker. If None, all exceptions coming from workers are caught and the execution is allowed to continue.

Raises:

ValueError – If there are duplicated workers in workers when using multithreading.

execute(input_values, exec_callback=None, task_submitted_callback=None)[source]

Execute all the processes.

Parameters:

  • input_values (Sequence[ndarray] | ndarray) – The input values.

  • exec_callback (Callable[[int, Any], Any] | None) – A callback function called with the pair (index, outputs) as arguments when an item is retrieved from the processing. Index is the associated index in input_values of the input used to compute the outputs. If None, no function is called.

  • task_submitted_callback (Callable | None) – A callback function called when all the tasks are submitted, but not done yet. If None, no function is called.

Returns:

The computed outputs.

Raises:

TypeError – If the exec_callback is not callable. If the task_submitted_callback is not callable.

Return type:

dict[int, Any]

Warning

This class relies on multiprocessing features, it is therefore necessary to protect its execution with an if __name__ == '__main__': statement when working on Windows.

N_CPUS = 2
input_values: ndarray | None

The input values to be passed to the workers.

n_processes: int

The maximum simultaneous number of threads or processes.

use_threading: bool

Whether to use threads instead of processes to parallelize the execution.

wait_time_between_fork: float

The time to wait between two forks of the process/thread.

workers: ParallelExecutionWorkerType

The objects that perform the tasks.

gemseo.core.parallel_execution.worker(par_exe, queue_in, queue_out)[source]

Execute a function while there are args left in the queue_in.

Parameters:
Return type:

None