fix mutex race

source/prosperon.c

@@ -233,21 +233,26 @@ prosperon_rt *create_actor(int argc, char **argv, void (*hook)(JSContext*))
 
 prosperon_rt *get_actor(char *id)
 {
-  int idx = shgeti(actors, id);
-  if (idx == -1) return NULL;
-  prosperon_rt *actor;
   SDL_LockMutex(actors_mutex);
-  actor = actors[idx].value;
+  int idx = shgeti(actors, id);
+  if (idx == -1) {
+    SDL_UnlockMutex(actors_mutex);
+    return NULL;
+  }
+  prosperon_rt *actor = actors[idx].value;
   SDL_UnlockMutex(actors_mutex);
   return actor;
 }
 
 const char *register_actor(const char *id, prosperon_rt *actor, int mainthread)
 {
-  if (shgeti(actors, id) != -1) return "Actor with given ID already exists.";
+  SDL_LockMutex(actors_mutex);
+  if (shgeti(actors, id) != -1) {
+    SDL_UnlockMutex(actors_mutex);
+    return "Actor with given ID already exists.";
+  }
   actor->main_thread_only = mainthread;
   actor->id = strdup(id);
-  SDL_LockMutex(actors_mutex);
   shput(actors, id, actor);
   SDL_UnlockMutex(actors_mutex);
   return NULL;
@@ -267,9 +272,10 @@ const char *send_message(const char *id, void *msg)
     SDL_RemoveTimer(target->ar);
     target->ar = 0;
   }
-  set_actor_state(target);
   SDL_UnlockMutex(target->msg_mutex);
   
+  set_actor_state(target);
+  
   return NULL;
 }
 
@@ -1570,7 +1576,9 @@ int main(int argc, char **argv)
 
 int actor_exists(const char *id)
 {
+  SDL_LockMutex(actors_mutex);
   int idx = shgeti(actors,id);
+  SDL_UnlockMutex(actors_mutex);
   if (idx == -1)
     return 0;
   else