Class

NumCosmoMathMPIJob

Description [src]

abstract class NumCosmoMath.MPIJob : GObject.Object
{
  /* No available fields */
}

Abstract class to implement MPI jobs.

This abstract class simplifies the implementation of MPI jobs through a master/slave model. Subclasses must implement virtual methods. The master dispatches jobs to the slaves, awaits results, and slaves execute the job, sending results back to the master.

For example, NcmMPIJobMCMC is a specific subclass that implements an MCMC job. Each slave creates an instance of NcmLikelihood, evaluating the likelihood function for samples received from the master.

The master/slave model leverages MPI. The subclass is responsible for implementing virtual methods for packing/unpacking input and return objects into/from MPI buffers.

When NumCosmo is compiled with MPI support, the rank 0 process executes normally, while other ranks wait for commands from the master. The method ncm_mpi_job_init_all_slaves() sends a serialized version of itself to all slaves. Slaves deserialize it and wait for commands.

Each call to ncm_mpi_job_run_array() sends an array of inputs to the slaves in a round-robin fashion. Slaves execute the job and return results to the master, maintaining the input order. This method uses rank 0 to control the slaves, so the master isn’t involved in computations.

Conversely, ncm_mpi_job_run_array_async() sends inputs to the slaves and creates a lightweight thread to receive results while the master concurrently executes the job.

After job completion, the master calls ncm_mpi_job_free_all_slaves() to release the slaves. It’s an error to use two or more instances of any subclass of NcmMPIJob simultaneously.

Ancestors

GObject

Descendants

Functions

ncm_mpi_job_clear

Decrease the reference count of mpi_job by one, and sets the pointer *mpi_job to NULL.

Instance methods

ncm_mpi_job_create_input

Creates a new input object.

ncm_mpi_job_create_return

Creates a new return object.

ncm_mpi_job_destroy_input

Destroy the input object created with ncm_mpi_job_create_input().

ncm_mpi_job_destroy_input_buffer

Destroy buf created with ncm_mpi_job_get_input_buffer() or ncm_mpi_job_pack_input().

ncm_mpi_job_destroy_return

Destroy the return object created with ncm_mpi_job_create_return().

ncm_mpi_job_destroy_return_buffer

Destroy buf created with ncm_mpi_job_get_return_buffer() or ncm_mpi_job_pack_return().

ncm_mpi_job_free

Decrease the reference count of mpi_job by one.

ncm_mpi_job_free_all_slaves

Frees all available slaves used by mpi_job.

ncm_mpi_job_get_input_buffer

Creates a buffer from input compatible with ncm_mpi_job_input_datatype().

ncm_mpi_job_get_return_buffer

Creates a buffer from ret compatible with ncm_mpi_job_return_datatype().

ncm_mpi_job_init_all_slaves

Initialize all available slaves with mpi_job.

ncm_mpi_job_input_datatype

Computes the size and datatype of the input buffer.

ncm_mpi_job_pack_input

Packs (when necessary) the input into the input buffer.

ncm_mpi_job_pack_return

Packs (when necessary) the return into the return buffer buf.

ncm_mpi_job_ref

Increase the reference of mpi_job by one.

ncm_mpi_job_return_datatype

Computes the size and datatype of the return buffer.

ncm_mpi_job_run

Runs job mpi_job using input and returns in ret.

ncm_mpi_job_run_array

Send work to all slaves in a round-robin fashion. Both arrays input_array and ret_array must have the same length and should be filled with the appropriated pointers.

ncm_mpi_job_run_array_async

Send work to all slaves using an additional thread to control the slaves work. The main execution thread runs jobs in parallel while it waits for the slaves to finish. Both arrays input_array and ret_array must have the same length and should be filled with the appropriated pointers.

ncm_mpi_job_unpack_input

Unpacks (when necessary) the buffer buf into the input pointer input.

ncm_mpi_job_unpack_return

Unpacks (when necessary) the buffer buf into the return pointer return.

ncm_mpi_job_work_clear

Method called during the working phase of mpi_job and in the end before object destruction. This method can be called multiple times during the work phase.

ncm_mpi_job_work_init

Method called after mpi_job is initialized at the slave and before start working.

Methods inherited from GObject (43)

Please see GObject for a full list of methods.

Properties

NumCosmoMath.MPIJob:placeholder

No description available.

Signals

Signals inherited from GObject (1)

GObject::notify

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.

Class structure

struct NumCosmoMathMPIJobClass {
  void (* work_init) (
    NcmMPIJob* mpi_job
  );
  void (* work_clear) (
    NcmMPIJob* mpi_job
  );
  NcmMPIDatatype (* input_datatype) (
    NcmMPIJob* mpi_job,
    gint* len,
    gint* size
  );
  NcmMPIDatatype (* return_datatype) (
    NcmMPIJob* mpi_job,
    gint* len,
    gint* size
  );
  gpointer (* create_input) (
    NcmMPIJob* mpi_job
  );
  gpointer (* create_return) (
    NcmMPIJob* mpi_job
  );
  void (* destroy_input) (
    NcmMPIJob* mpi_job,
    gpointer input
  );
  void (* destroy_return) (
    NcmMPIJob* mpi_job,
    gpointer ret
  );
  gpointer (* get_input_buffer) (
    NcmMPIJob* mpi_job,
    gpointer input
  );
  gpointer (* get_return_buffer) (
    NcmMPIJob* mpi_job,
    gpointer ret
  );
  void (* destroy_input_buffer) (
    NcmMPIJob* mpi_job,
    gpointer input,
    gpointer buf
  );
  void (* destroy_return_buffer) (
    NcmMPIJob* mpi_job,
    gpointer ret,
    gpointer buf
  );
  gpointer (* pack_input) (
    NcmMPIJob* mpi_job,
    gpointer input
  );
  gpointer (* pack_return) (
    NcmMPIJob* mpi_job,
    gpointer ret
  );
  void (* unpack_input) (
    NcmMPIJob* mpi_job,
    gpointer buf,
    gpointer input
  );
  void (* unpack_return) (
    NcmMPIJob* mpi_job,
    gpointer buf,
    gpointer ret
  );
  void (* run) (
    NcmMPIJob* mpi_job,
    gpointer input,
    gpointer ret
  );
  
}