Fix thread safety issue in OpenMM minimiser. [closes #259]

doc/source/changelog.rst

@@ -16,9 +16,6 @@ organisation on `GitHub <https://github.com/openbiosim/sire>`__.
 ---------------------------------------------------------------------------------------------
 
 * Please add an item to this CHANGELOG for any new features or bug fixes when creating a PR.
-* Fixed :func:`sire.restraints.get_standard_state_correction` to be consistent with the definition of
-  the "force constanst" as ``F = 2 ** k ** x`` (rather than ``F = k ** x``). Updated docstrings and
-  restraints documentation to make it clear how the force constants are defined.
 * Fixed instantiaton of ``QByteArray`` in ``Sire::Mol::Frame::toByteArray`` and count bytes with ``QByteArray::size``.
 * Increase timeout before terminating ``QThread`` objects during ``PageCache`` cleanup.
 * Expose missing ``timeout`` kwarg in :meth:`dynamics.minimise()` method.
@@ -27,6 +24,10 @@ organisation on `GitHub <https://github.com/openbiosim/sire>`__.
 * Reload TorchQMForce module if OpenMM platform changes.
 * Fix calculation of non-equilibrium work when starting from QM state.
 * Fix stereochemistry in RDKit molecule conversion.
+* Fixed :func:`sire.restraints.get_standard_state_correction` to be consistent with the definition of
+  the "force constanst" as ``F = 2 ** k ** x`` (rather than ``F = k ** x``). Updated docstrings and
+  restraints documentation to make it clear how the force constants are defined.
+* Fix thread safety issue in Sire OpenMM minimiser.
 
 `2024.3.0 <https://github.com/openbiosim/sire/compare/2024.2.0...2024.3.0>`__ - October 2024
 --------------------------------------------------------------------------------------------

wrapper/Convert/SireOpenMM/openmmminimise.cpp

@@ -50,6 +50,7 @@
 #include <limits.h> // CHAR_BIT
 #include <sstream>
 #include <stdint.h> // uint64_t
+#include <Python.h>
 
 inline auto is_ieee754_nan(double const x)
     -> bool
@@ -91,7 +92,6 @@ inline auto is_ieee754_nan(double const x)
 #include <algorithm>
 
 #include "SireError/errors.h"
-#include "SireBase/releasegil.h"
 
 #include "SireBase/progressbar.h"
 #include "SireUnits/units.h"
@@ -619,6 +619,8 @@ namespace SireOpenMM
                                     double starting_k, double ratchet_scale,
                                     double max_constraint_error, double timeout)
     {
+        PyThreadState *_save = PyEval_SaveThread();
+
         if (max_iterations < 0)
         {
             max_iterations = std::numeric_limits<int>::max();
@@ -629,8 +631,6 @@ namespace SireOpenMM
             timeout = std::numeric_limits<double>::max();
         }
 
-        auto gil = SireBase::release_gil();
-
         const OpenMM::System &system = context.getSystem();
 
         int num_particles = system.getNumParticles();
@@ -1105,6 +1105,8 @@ namespace SireOpenMM
                                            CODELOC);
         }
 
+        PyEval_RestoreThread(_save);
+
         return data.getLog().join("\n");
     }