MOSEK: Remove explicit use of mosek.Env (refactored) (#488)

* MOSEK: Remove use of Env

* release note for MOSEK

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* WIP

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* fix broken call in mosek setup

* Improve deprecation warnings and docstrings for MOSEK env parameter

---------

Co-authored-by: ulfw <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Lukas Trippe <[email protected]>

Author: 4 people

doc/release_notes.rst

@@ -10,6 +10,7 @@ Version 0.5.6
 
 * Improved variable/expression arithmetic methods so that they correctly handle types
 * Gurobi: Pass dictionary as env argument `env={...}` through to gurobi env creation
+* Mosek: Remove explicit use of Env, use global env instead
 
 **Breaking Changes**
 

linopy/solvers.py

@@ -13,6 +13,7 @@
 import re
 import subprocess as sub
 import sys
+import warnings
 from abc import ABC, abstractmethod
 from collections import namedtuple
 from collections.abc import Callable, Generator
@@ -100,10 +101,8 @@
     import mosek
 
     with contextlib.suppress(mosek.Error):
-        with mosek.Env() as m:
-            t = m.Task()
-            t.optimize()
-            m.checkinall()
+        t = mosek.Task()
+        t.optimize()
 
         available_solvers.append("mosek")
 
@@ -1661,33 +1660,37 @@ def solve_problem_from_model(
             Path to the warmstart file.
         basis_fn : Path, optional
             Path to the basis file.
-        env : None, optional
-            Mosek environment for the solver
+        env : None, optional, deprecated
+            Deprecated. This parameter is ignored. MOSEK now uses the global
+            environment automatically. Will be removed in a future version.
         explicit_coordinate_names : bool, optional
             Transfer variable and constraint names to the solver (default: False)
 
         Returns
         -------
         Result
         """
-        with contextlib.ExitStack() as stack:
-            if env is None:
-                env_ = stack.enter_context(mosek.Env())
 
-            with env_.Task() as m:
-                m = model.to_mosek(
-                    m, explicit_coordinate_names=explicit_coordinate_names
-                )
+        if env is not None:
+            warnings.warn(
+                "The 'env' parameter in solve_problem_from_model is deprecated and will be "
+                "removed in a future version. MOSEK now uses the global environment "
+                "automatically, avoiding unnecessary license checkouts.",
+                DeprecationWarning,
+                stacklevel=2,
+            )
+        with mosek.Task() as m:
+            m = model.to_mosek(m, explicit_coordinate_names=explicit_coordinate_names)
 
-                return self._solve(
-                    m,
-                    solution_fn=solution_fn,
-                    log_fn=log_fn,
-                    warmstart_fn=warmstart_fn,
-                    basis_fn=basis_fn,
-                    io_api="direct",
-                    sense=model.sense,
-                )
+            return self._solve(
+                m,
+                solution_fn=solution_fn,
+                log_fn=log_fn,
+                warmstart_fn=warmstart_fn,
+                basis_fn=basis_fn,
+                io_api="direct",
+                sense=model.sense,
+            )
 
     def solve_problem_from_file(
         self,
@@ -1714,34 +1717,39 @@ def solve_problem_from_file(
             Path to the warmstart file.
         basis_fn : Path, optional
             Path to the basis file.
-        env : None, optional
-            Mosek environment for the solver
+        env : None, optional, deprecated
+            Deprecated. This parameter is ignored. MOSEK now uses the global
+            environment automatically. Will be removed in a future version.
 
         Returns
         -------
         Result
         """
-        with contextlib.ExitStack() as stack:
-            if env is None:
-                env_ = stack.enter_context(mosek.Env())
-
-            with env_.Task() as m:
-                # read sense and io_api from problem file
-                sense = read_sense_from_problem_file(problem_fn)
-                io_api = read_io_api_from_problem_file(problem_fn)
-                # for Mosek solver, the path needs to be a string
-                problem_fn_ = path_to_string(problem_fn)
-                m.readdata(problem_fn_)
-
-                return self._solve(
-                    m,
-                    solution_fn=solution_fn,
-                    log_fn=log_fn,
-                    warmstart_fn=warmstart_fn,
-                    basis_fn=basis_fn,
-                    io_api=io_api,
-                    sense=sense,
-                )
+        if env is not None:
+            warnings.warn(
+                "The 'env' parameter in solve_problem_from_file is deprecated and will be "
+                "removed in a future version. MOSEK now uses the global environment "
+                "automatically, avoiding unnecessary license checkouts.",
+                DeprecationWarning,
+                stacklevel=2,
+            )
+        with mosek.Task() as m:
+            # read sense and io_api from problem file
+            sense = read_sense_from_problem_file(problem_fn)
+            io_api = read_io_api_from_problem_file(problem_fn)
+            # for Mosek solver, the path needs to be a string
+            problem_fn_ = path_to_string(problem_fn)
+            m.readdata(problem_fn_)
+
+            return self._solve(
+                m,
+                solution_fn=solution_fn,
+                log_fn=log_fn,
+                warmstart_fn=warmstart_fn,
+                basis_fn=basis_fn,
+                io_api=io_api,
+                sense=sense,
+            )
 
     def _solve(
         self,