Some refactor fixes

Signed-off-by: Igoshev, Iaroslav <[email protected]>

docs/using_unidist/unidist_on_mpi.rst

@@ -58,7 +58,7 @@ To run unidist on MPI in a single node using Controller/Worker model you should
 
 MPI worker processes will be spawned dynamically by unidist.
 
-It is worth noting that `Intel MPI implementation <https://anaconda.org/intel/mpi4py>`_ supports the ability of spawning MPI processes
+It is worth noting that some MPI implementations, e.g., `Intel MPI implementation`_, support the ability of spawning MPI processes
 without using ``mpiexec`` command so you can run unidist on Intel MPI just with:
 
 .. code-block:: bash
@@ -122,12 +122,12 @@ Running is almost the same as in a single node, but, in addition,
 you should use the appropriate parameter for ``mpiexec``.
 This parameter differs depending on the MPI implementation used.
 
-* For Intel MPI or MPICH: ``-hosts host1,host2``. You can also see `Controlling Process Placement with the Intel® MPI Library`_ 
-or `MPICH wiki`_ for deeper customization.
-
-* For OpenMPI: ``-host host1:n1,...,hostM:nM``
-where n1, ..., nM is the number of processes on each node, including Unidist service processes (root and one or some monitors).
-You can also see `Scheduling processes across hosts with OpenMPI Library <https://docs.open-mpi.org/en/v5.0.x/launching-apps/scheduling.html>`_ for deeper customization. 
+* For Intel MPI or MPICH: ``-hosts host1,host2``.
+  You can also see `Controlling Process Placement with the Intel® MPI Library`_  or
+  `MPICH wiki`_ for deeper customization.
+* For OpenMPI: ``-host host1:n1,...,hostM:nM``, where n1, ..., nM is the number of processes on each node,
+  including unidist service processes (root and monitor(s)).
+  You can also see `Scheduling processes across hosts with OpenMPI Library`_ for deeper customization. 
 
 Running without ``mpiexec`` command
 -----------------------------------
@@ -171,5 +171,7 @@ Running is the same as in a single node.
 
 
 .. _`SPMD model`: https://en.wikipedia.org/wiki/Single_program,_multiple_data
+.. _`Intel MPI implementation`: https://anaconda.org/intel/mpi4py
 .. _`Controlling Process Placement with the Intel® MPI Library`: https://www.intel.com/content/www/us/en/developer/articles/technical/controlling-process-placement-with-the-intel-mpi-library.html
-.. _`MPICH wiki`: https://github.com/pmodels/mpich/blob/main/doc/wiki/how_to/Using_the_Hydra_Process_Manager.md
+.. _`MPICH wiki`: https://github.com/pmodels/mpich/blob/main/doc/wiki/how_to/Using_the_Hydra_Process_Manager.md
+.. _`Scheduling processes across hosts with OpenMPI Library`: https://docs.open-mpi.org/en/v5.0.x/launching-apps/scheduling.html

unidist/core/backends/mpi/core/common.py

@@ -507,16 +507,12 @@ def is_run_with_mpiexec():
     if "Intel" in lib_version and os.getenv("PMI_RANK") is None:
         return False
 
-    if "MPICH" in MPI.Get_library_version() and os.getenv("PMI_RANK") is None:
+    if "MPICH" in lib_version and os.getenv("PMI_RANK") is None:
         return False
 
-    if (
-        "Open MPI" in MPI.Get_library_version()
-        and os.getenv("OMPI_COMM_WORLD_RANK") is None
-    ):
+    if "Open MPI" in lib_version and os.getenv("OMPI_COMM_WORLD_RANK") is None:
         return False
 
     # The latest MSMPI does not support running without mpiexec.
     # Other MPI libraries haven't been checked.
-
     return True

unidist/core/backends/mpi/core/communication.py

@@ -139,18 +139,15 @@ def __init__(self, comm):
             # check running hosts
             if self.is_root_process() and len(self.topology.keys()) > host_count:
                 warnings.warn(
-                    """The number of running hosts is greater than that specified in the UNIDIST_MPI_HOSTS.
-                    If you want to run the program on a host other than the local one, specify the appropriate parameter for `mpiexec`
-                    (`--host` for OpenMPI or `--hosts` for other MPI implementations)
-                """
+                    "The number of running hosts is greater than that specified in the UNIDIST_MPI_HOSTS. "
+                    + "If you want to run the program on a host other than the local one, specify the appropriate parameter for `mpiexec` "
+                    + "(`--host` for OpenMPI and `--hosts` for Intel MPI or MPICH)."
                 )
-
-            # check running hosts
             if self.is_root_process() and len(self.topology.keys()) < host_count:
                 warnings.warn(
-                    "The number of running hosts is less than that specified in the UNIDIST_MPI_HOSTS. Check the `mpiexec` option to distribute processes between hosts."
+                    "The number of running hosts is less than that specified in the UNIDIST_MPI_HOSTS. "
+                    + "Check the `mpiexec` option to distribute processes between hosts."
                 )
-
         if common.is_shared_memory_supported():
             self.monitor_processes = []
             for host in self.topology:

unidist/core/backends/mpi/core/controller/api.py

@@ -159,12 +159,11 @@ def init():
         if MpiHosts.get_value_source() != ValueSource.DEFAULT:
             if common.is_run_with_mpiexec():
                 warnings.warn(
-                    "MpiHosts is not used when running a script using mpiexec."
-                    + "Find out more about running Unidist on MPI cluster in the Unidist documentation."
+                    "MpiHosts is not used when running a script using mpiexec. "
+                    + "Find out more about running unidist on MPI cluster in the unidist documentation."
                 )
             else:
                 py_str += [f"cfg.MpiHosts.put('{MpiHosts.get()}')"]
-
         if CpuCount.get_value_source() != ValueSource.DEFAULT:
             py_str += [f"cfg.CpuCount.put({CpuCount.get()})"]
         if MpiPickleThreshold.get_value_source() != ValueSource.DEFAULT:
@@ -206,15 +205,12 @@ def init():
             # See more about Intel MPI environment variables in
             # https://www.intel.com/content/www/us/en/docs/mpi-library/developer-reference-linux/2021-8/other-environment-variables.html.
             os.environ["I_MPI_SPAWN"] = "1"
-
         # +1 for just a single process monitor
         nprocs_to_spawn = cpu_count + 1
-
         hosts = MpiHosts.get()
         if hosts is not None and not common.is_run_with_mpiexec():
             host_list = hosts.split(",")
             host_count = len(host_list)
-
             if common.is_shared_memory_supported():
                 # +host_count to add monitor process on each host
                 nprocs_to_spawn = cpu_count + host_count