POC + WIP: Support multiprocessing Version 2

pygmt/__init__.py

@@ -19,6 +19,7 @@
 """
 
 import atexit as _atexit
+import os
 
 # Import modules to make the high-level GMT Python API
 from pygmt import datasets
@@ -66,6 +67,8 @@
     xyz2grd,
 )
 
+# Set the session name to the current process ID. Necessary for multiprocessing support.
+os.environ["GMT_SESSION_NAME"] = str(os.getpid())
 # Start our global modern mode session
 _begin()
 # Tell Python to run _end when shutting down

pygmt/session_management.py

@@ -2,11 +2,7 @@
 Modern mode session management modules.
 """
 
-import os
-import sys
-
 from pygmt.clib import Session
-from pygmt.helpers import unique_name
 
 
 def begin():
@@ -17,10 +13,6 @@ def begin():
 
     Only meant to be used once for creating the global session.
     """
-    # On Windows, need to set GMT_SESSION_NAME to a unique value
-    if sys.platform == "win32":
-        os.environ["GMT_SESSION_NAME"] = unique_name()
-
     prefix = "pygmt-session"
     with Session() as lib:
         lib.call_module(module="begin", args=[prefix])

pygmt/tests/test_session_management.py

@@ -3,9 +3,9 @@
 """
 
 import multiprocessing as mp
-from importlib import reload
 from pathlib import Path
 
+import pygmt
 import pytest
 from pygmt.clib import Session
 from pygmt.session_management import begin, end
@@ -65,13 +65,7 @@ def test_gmt_compat_6_is_applied(capsys):
 def _gmt_func_wrapper(figname):
     """
     A wrapper for running PyGMT scripts with multiprocessing.
-
-    Currently, we have to import pygmt and reload it in each process. Workaround from
-    https://github.com/GenericMappingTools/pygmt/issues/217#issuecomment-754774875.
     """
-    import pygmt
-
-    reload(pygmt)
     fig = pygmt.Figure()
     fig.basemap(region=[10, 70, -3, 8], projection="X8c/6c", frame="afg")
     fig.savefig(figname)