Add new mju_threadpool API function, and delete old threading API.

PiperOrigin-RevId: 922838541
Change-Id: Id9f7e0fb298ffde61fcc49a802dc78971858ce51

src/engine/engine_io.c

@@ -33,6 +33,7 @@
 #include "engine/engine_memory.h"
 #include "engine/engine_plugin.h"
 #include "engine/engine_sleep.h"
+#include "engine/engine_thread.h"
 #include "engine/engine_util_blas.h"
 #include "engine/engine_util_errmem.h"
 #include "engine/engine_util_misc.h"
@@ -1081,6 +1082,7 @@ void mj_makeRawData(mjData** dest, const mjModel* m) {
 
   // clear threadpool
   d->threadpool = 0;
+  d->threadlock = 0;
 
   // clear nplugin (overwritten by _initPlugin)
   d->nplugin = 0;
@@ -1140,6 +1142,7 @@ mjData* mj_copyDataVisual(mjData* dest, const mjModel* m, const mjData* src, int
   *dest = *src;
   dest->buffer = save_buffer;
   dest->arena = save_arena;
+  dest->threadpool = 0;
   mj_setPtrData(m, dest);
 
   // save plugin_data, since the X macro copying block below will override it
@@ -1239,8 +1242,6 @@ mjData* mj_copyDataVisual(mjData* dest, const mjModel* m, const mjData* src, int
     }
   }
 
-  dest->threadpool = src->threadpool;
-
   return dest;
 }
 
@@ -1300,7 +1301,6 @@ static void _resetData(const mjModel* m, mjData* d, unsigned char debug_value) {
 
   // clear memory utilization stats
   d->maxuse_stack = 0;
-  memset(d->maxuse_threadstack, 0, mjMAXTHREAD*sizeof(mjtSize));
   d->maxuse_arena = 0;
   d->maxuse_con = 0;
   d->maxuse_efc = 0;
@@ -1572,6 +1572,7 @@ void mj_resetDataKeyframe(const mjModel* m, mjData* d, int key) {
 // de-allocate mjData
 void mj_deleteData(mjData* d) {
   if (d) {
+    mju_threadpool(d, 0);
     freeDataBuffers(d);
     mju_free(d);
   }