Ability to unload PyGeNN models

pygenn/genn_groups.py

@@ -321,6 +321,25 @@ def _load_var_init_egps(self, var_dict=None):
         for var_name, var_data in iteritems(var_dict):
             self._load_egp(var_data.extra_global_params, var_name)
 
+    def _unload_vars(self, var_dict=None):
+        # If no variable dictionary is specified, use standard one
+        if var_dict is None:
+            var_dict = self.vars
+
+        # Loop through variables and clear views
+        for v in itervalues(var_dict):
+            v.view = None
+            for e in itervalues(v.extra_global_params):
+                e.view = None
+
+    def _unload_egps(self, egp_dict=None):
+        # If no EGP dictionary is specified, use standard one
+        if egp_dict is None:
+            egp_dict = self.extra_global_params
+
+        # Loop through extra global params and clear views
+        for e in itervalues(egp_dict):
+            e.view = None
 
 class NeuronGroup(Group):
 
@@ -339,12 +358,14 @@ def __init__(self, name, model):
         self.spike_count = None
         self.spike_events = None
         self.spike_event_count = None
-        self.spike_que_ptr = [0]
+        self.spike_que_ptr = None
         self._max_delay_steps = 0
         self.spike_times = None
         self.prev_spike_times = None
         self.spike_event_times = None
         self.prev_spike_event_times = None
+        self._spike_recording_data = None
+        self._spike_event_recording_data = None
 
     @property
     def current_spikes(self):
@@ -591,6 +612,22 @@ def load(self, num_recording_timesteps):
         # Load neuron extra global params
         self._load_egp()
 
+    def unload(self):
+        self.spikes = None
+        self.spike_count = None
+        self.spike_events = None
+        self.spike_event_count = None
+        self.spike_que_ptr = None
+        self.spike_times = None
+        self.prev_spike_times = None
+        self.spike_event_times = None
+        self.prev_spike_event_times = None
+        self._spike_recording_data = None
+        self._spike_event_recording_data = None
+
+        self._unload_vars()
+        self._unload_egps()
+
     def load_init_egps(self):
         # Load any egps used for variable initialisation
         self._load_var_init_egps()
@@ -1293,6 +1330,19 @@ def load_init_egps(self):
         self._load_var_init_egps(self.pre_vars)
         self._load_var_init_egps(self.post_vars)
 
+    def unload(self):
+        self._ind = None
+        self._row_lengths = None
+        self.in_syn = None
+
+        self._unload_vars()
+        self._unload_vars(self.pre_vars)
+        self._unload_vars(self.post_vars)
+        self._unload_vars(self.psm_vars)
+        self._unload_egps()
+        self._unload_egps(self.psm_extra_global_params)
+        self._unload_egps(self.connectivity_extra_global_params)
+
     def reinitialise(self):
         """Reinitialise synapse group"""
         # If population has individual synapse variables
@@ -1416,6 +1466,10 @@ def load_init_egps(self):
         # Load any egps used for variable initialisation
         self._load_var_init_egps()
 
+    def unload(self):
+        self._unload_vars()
+        self._unload_egps()
+
     def reinitialise(self):
         """Reinitialise current source"""
         # Reinitialise current source state variables
@@ -1547,6 +1601,10 @@ def load_init_egps(self):
         # Load any egps used for variable initialisation
         self._load_var_init_egps()
 
+    def unload(self):
+        self._unload_vars()
+        self._unload_egps()
+
     def reinitialise(self):
         """Reinitialise custom update"""
         # If this is a custom weight update

pygenn/genn_model.py

@@ -646,7 +646,7 @@ def load(self, path_to_model="./", num_recording_timesteps=None):
             # Allocate recording buffers
             self._slm.allocate_recording_buffers(num_recording_timesteps)
 
-        # Loop through synapse populations and load any 
+        # Loop through neuron populations and load any
         # extra global parameters required for initialization
         for pop_data in itervalues(self.neuron_populations):
             pop_data.load_init_egps()
@@ -690,6 +690,29 @@ def load(self, path_to_model="./", num_recording_timesteps=None):
         self._loaded = True
         self._built = True
 
+    def unload(self):
+        # Loop through custom updates and unload
+        for cu_data in itervalues(self.custom_updates):
+            cu_data.unload()
+
+        # Loop through current sources and unload
+        for src_data in itervalues(self.current_sources):
+            src_data.unload()
+
+        # Loop through synapse populations and unload
+        for pop_data in itervalues(self.synapse_populations):
+            pop_data.unload()
+
+        # Loop through neuron populations and unload
+        for pop_data in itervalues(self.neuron_populations):
+            pop_data.unload()
+
+        # Close shared library model
+        self._slm.close()
+
+        # Clear loaded flag
+        self._loaded = False
+
     def reinitialise(self):
         """reinitialise model to its original state without re-loading"""
         if not self._loaded:

userproject/include/sharedLibraryModel.h

@@ -50,15 +50,8 @@ class SharedLibraryModel
 
     virtual ~SharedLibraryModel()
     {
-        // Close model library if loaded successfully
-        if(m_Library) {
-            freeMem();
-#ifdef _WIN32
-            FreeLibrary(m_Library);
-#else
-            dlclose(m_Library);
-#endif
-        }
+        // Close model library
+        close();
     }
 
     //----------------------------------------------------------------------------
@@ -112,6 +105,40 @@ class SharedLibraryModel
         }
     }
 
+    void close()
+    {
+        if(m_Library) {
+            freeMem();
+#ifdef _WIN32
+            FreeLibrary(m_Library);
+#else
+            dlclose(m_Library);
+#endif
+            m_Library = nullptr;
+        }
+
+        // Null all pointers
+        m_AllocateMem = nullptr;
+        m_AllocateRecordingBuffers = nullptr;
+        m_FreeMem = nullptr;
+        m_GetFreeDeviceMemBytes = nullptr;
+        m_Initialize = nullptr;
+        m_InitializeSparse = nullptr;
+        m_StepTime = nullptr;
+        m_PullRecordingBuffersFromDevice = nullptr;
+        m_NCCLGenerateUniqueID = nullptr;
+        m_NCCLGetUniqueID = nullptr;
+        m_NCCLInitCommunicator = nullptr;
+        m_NCCLUniqueIDBytes = nullptr;
+        m_T = nullptr;
+        m_Timestep = nullptr;
+
+        // Empty all dictionaries
+        m_PopulationVars.clear();
+        m_PopulationEPGs.clear();
+        m_CustomUpdates.clear();
+    }
+
     void allocateExtraGlobalParam(const std::string &popName, const std::string &egpName, unsigned int count)
     {
         // Get EGP functions and check allocate exists