Add maxuse_threadstack to mjData

PiperOrigin-RevId: 567334177
Change-Id: Ifd772350042e548a63ab269fd68fb5e5fef55831

src/engine/engine_io.c

@@ -1420,6 +1420,7 @@ static void _resetData(const mjModel* m, mjData* d, unsigned char debug_value) {
 
   // clear memory utilization stats
   d->maxuse_stack = 0;
+  mju_zeroSizeT(d->maxuse_threadstack, mjMAXTHREADS);
   d->maxuse_arena = 0;
   d->maxuse_con = 0;
   d->maxuse_efc = 0;

src/engine/engine_util_misc.c

@@ -1213,6 +1213,10 @@ void mju_zeroInt(int* res, int n) {
 }
 
 
+void mju_zeroSizeT(size_t* res, size_t n) {
+  memset(res, 0, n*sizeof(size_t));
+}
+
 
 // copy int vector vec into res
 void mju_copyInt(int* res, const int* vec, int n) {

src/engine/engine_util_misc.h

@@ -122,6 +122,9 @@ MJAPI int mju_isZero(mjtNum* vec, int n);
 // set integer vector to 0
 MJAPI void mju_zeroInt(int* res, int n);
 
+// set size_t vector to 0
+MJAPI void mju_zeroSizeT(size_t* res, size_t n);
+
 // copy int vector vec into res
 MJAPI void mju_copyInt(int* res, const int* vec, int n);
 

src/thread/thread_pool.cc

@@ -14,6 +14,7 @@
 
 #include "thread/thread_pool.h"
 
+#include <algorithm>
 #include <atomic>
 #include <cstddef>
 #include <memory>
@@ -55,7 +56,7 @@ class ThreadPoolImpl : public mjThreadPool {
  public:
   ThreadPoolImpl(int num_worker) : mjThreadPool{num_worker} {
     // initialize worker threads
-    for (int i = 0; i < num_worker; ++i) {
+    for (int i = 0; i < std::min(num_worker, mjMAXTHREADS); ++i) {
       WorkerThread worker{
         std::make_unique<std::thread>(ThreadPoolWorker, this)};
       workers_.push_back(std::move(worker));