Simulate: fix reload button causing segfault, make interface changes needed for Python bindings

simulate/Makefile

@@ -7,6 +7,7 @@ COMMON=-O2 -I../include -L../lib -std=c++11 -pthread -Wl,-rpath,'$$ORIGIN'/../li
 all:
 	$(CC)  -c -O2 -fPIC -I../include uitools.c
 	$(CXX) -c -O2 -fPIC -I../include simulate.cc
-	$(CXX) -shared -o libmjsimulate.so simulate.o uitools.o
-	mv libmjsimulate.so ../lib/libmjsimulate.so
+	$(CXX) $(COMMON) -shared -Wl,-no-as-needed -Wl,-soname,libmjsimulate.so.2.1.5 -lmujoco -o libmjsimulate.so.2.1.5 simulate.o uitools.o
+	mv libmjsimulate.so.2.1.5 ../lib/libmjsimulate.so.2.1.5
+	ln -sf ../lib/libmjsimulate.so.2.1.5 ../lib/libmjsimulate.so
 	$(CXX) $(COMMON) -Wl,-no-as-needed main.cc -lmjsimulate -lmujoco -lGL -lglfw -o ../bin/simulate

simulate/main.cc

@@ -102,15 +102,37 @@ void SimulateLoop(mj::Simulate& simulate) {
 
     if (simulate.droploadrequest) {
       mjModel* mnew = LoadModel(simulate.dropfilename, simulate);
+      simulate.droploadrequest = 0;
       if (mnew) {
         mjData* dnew = mj_makeData(mnew);
         simulate.load(simulate.dropfilename, mnew, dnew, true);
 
-        simulate.droploadrequest = 0;
+        m = mnew;
+        d = dnew;
+        mj_forward(m, d);
+
+        // allocate ctrlnoise
+        free(ctrlnoise);
+        ctrlnoise = (mjtNum*) malloc(sizeof(mjtNum)*m->nu);
+        mju_zero(ctrlnoise, m->nu);
+      }
+    }
+
+    if (simulate.uiloadrequest) {
+      mjModel* mnew = LoadModel(simulate.filename, simulate);
+      simulate.uiloadrequest = 0;
+      if (mnew) {
+        mjData* dnew = mj_makeData(mnew);
+        simulate.load(simulate.filename, mnew, dnew, true);
 
         m = mnew;
         d = dnew;
         mj_forward(m, d);
+
+        // allocate ctrlnoise
+        free(ctrlnoise);
+        ctrlnoise = (mjtNum*) malloc(sizeof(mjtNum)*m->nu);
+        mju_zero(ctrlnoise, m->nu);
       }
     }
 
@@ -157,8 +179,8 @@ void SimulateLoop(mj::Simulate& simulate) {
 
             // clear old perturbations, apply new
             mju_zero(d->xfrc_applied, 6*m->nbody);
-            mjv_applyPerturbPose(m, d, &simulate.pert, 0);  // move mocap bodies only
-            mjv_applyPerturbForce(m, d, &simulate.pert);
+            simulate.applyposepertubations(0); // move mocap bodies only
+            simulate.applyforceperturbations();
 
             // run single step, let next iteration deal with timing
             mj_step(m, d);
@@ -171,8 +193,8 @@ void SimulateLoop(mj::Simulate& simulate) {
                    (glfwGetTime()-tmstart) < refreshfactor/simulate.vmode.refreshRate) {
               // clear old perturbations, apply new
               mju_zero(d->xfrc_applied, 6*m->nbody);
-              mjv_applyPerturbPose(m, d, &simulate.pert, 0);  // move mocap bodies only
-              mjv_applyPerturbForce(m, d, &simulate.pert);
+              simulate.applyposepertubations(0); // move mocap bodies only
+              simulate.applyforceperturbations();
 
               // run mj_step
               mjtNum prevtm = d->time*simulate.slow_down;
@@ -189,7 +211,7 @@ void SimulateLoop(mj::Simulate& simulate) {
         // paused
         else {
           // apply pose perturbation
-          mjv_applyPerturbPose(m, d, &simulate.pert, 1);      // move mocap and dynamic bodies
+          simulate.applyposepertubations(1); // move mocap and dynamic bodies
 
           // run mj_forward, to update rendering and joint sliders
           mj_forward(m, d);
@@ -210,19 +232,9 @@ int main(int argc, const char** argv) {
     mju_error("Headers and library have different versions");
   }
 
-  // simulate object for encapsulates UI
+  // simulate object encapsulates the UI
   mj::Simulate simulate;
 
-  // request loadmodel if file given (otherwise drag-and-drop)
-  if (argc>1) {
-    m = LoadModel(argv[1], simulate);
-    if (m) {
-      d = mj_makeData(m);
-      simulate.load(argv[1], m, d, true);
-      mj_forward(m, d);
-    }
-  }
-
   // init GLFW
   if (!glfwInit()) {
     mju_error("could not initialize GLFW");
@@ -231,6 +243,21 @@ int main(int argc, const char** argv) {
   // start simulation thread (this creates the UI)
   simulate.startthread();
 
+  // request loadmodel if file given (otherwise drag-and-drop)
+  if (argc>1) {
+    m = LoadModel(argv[1], simulate);
+    if (m) {
+      d = mj_makeData(m);
+      simulate.load(argv[1], m, d, true);
+      mj_forward(m, d);
+
+      // allocate ctrlnoise
+      free(ctrlnoise);
+      ctrlnoise = (mjtNum*) malloc(sizeof(mjtNum)*m->nu);
+      mju_zero(ctrlnoise, m->nu);
+    }
+  }
+
   SimulateLoop(simulate);
 
   // If simulate loop exited its time to stop the UI

simulate/simulate.cc

@@ -1150,7 +1150,7 @@ void uiEvent(mjuiState* state) {
         break;
 
       case 2:             // Reload
-        simulate->loadrequest = 1;
+        simulate->uiloadrequest = 1;
         break;
 
       case 3:             // Align
@@ -1548,8 +1548,21 @@ void Simulate::stopthread(void) {
   this->renderthreadhandle.join();
 }
 
+//------------------------ apply pose perturbations ----------------------------
+void Simulate::applyposepertubations(int flg_paused) {
+  if (this->m != nullptr) {
+    mjv_applyPerturbPose(this->m, this->d, &this->pert, flg_paused);  // move mocap bodies only
+  }
+}
 
-//-------------------- Tell the render thread to load a file -------------------
+//------------------------ apply force perturbations ---------------------------
+void Simulate::applyforceperturbations(void) {
+  if (this->m != nullptr) {
+    mjv_applyPerturbForce(this->m, this->d, &this->pert);
+  }
+}
+
+//-------------------- Tell the render thread to load a file and wait ----------
 void Simulate::load(const char* file,
                     mjModel* mnew,
                     mjData* dnew,
@@ -1559,6 +1572,13 @@ void Simulate::load(const char* file,
   this->delete_old_m_d = delete_old_m_d;
   mju::strcpy_arr(this->filename, file);
   this->loadrequest = 2;
+
+  // Wait for the render thread to be done loading
+  // so that we know the old model and data's memory can
+  // be free'd by the other thread (sometimes python)
+  while (this->loadrequest > 0) {
+    std::this_thread::sleep_for(std::chrono::milliseconds(1));
+  }
 }
 
 //------------------------ load mjb or xml model -------------------------------

simulate/simulate.h

@@ -36,6 +36,12 @@ class Simulate {
   // Stop the Simulate UI thread
   void stopthread(void);
 
+  // Apply UI pose perturbations to model and data
+  void applyposepertubations(int flg_paused);
+
+  // Apply UI force perturbations to model and data
+  void applyforceperturbations(void);
+
   // Request that the Simulate UI thread render a new model
   // optionally delete the old model and data when done
   void load(const char* file, mjModel* m, mjData* d, bool delete_old_m_d);
@@ -91,6 +97,7 @@ class Simulate {
   // simulation
   int run = 1;
   int key = 0;
+  int uiloadrequest = 0;
   int droploadrequest = 0;
   int loadrequest = 0;
   // strings