// Based on the stack information in the linked list, allocate memory
// block to return and fill it from the info in the linked list.

void
VM_GetMultipleStackTraces::allocate_and_fill_stacks(jint thread_count) {

  {- -------------------------------------------
  (1) 
      ---------------------------------------- -}

      // do I need to worry about alignment issues?
      jlong alloc_size =  thread_count       * sizeof(jvmtiStackInfo)
                        + _frame_count_total * sizeof(jvmtiFrameInfo);
      env()->allocate(alloc_size, (unsigned char **)&_stack_info);

      // pointers to move through the newly allocated space as it is filled in
      jvmtiStackInfo *si = _stack_info + thread_count;      // bottom of stack info
      jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si;            // is the top of frame info

      // copy information in resource area into allocated buffer
      // insert stack info backwards since linked list is backwards
      // insert frame info forwards
      // walk the StackInfoNodes
      for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) {
        jint frame_count = sin->info.frame_count;
        size_t frames_size = frame_count * sizeof(jvmtiFrameInfo);
        --si;
        memcpy(si, &(sin->info), sizeof(jvmtiStackInfo));
        if (frames_size == 0) {
          si->frame_buffer = NULL;
        } else {
          memcpy(fi, sin->info.frame_buffer, frames_size);
          si->frame_buffer = fi;  // point to the new allocated copy of the frames
          fi += frame_count;
        }
      }
      assert(si == _stack_info, "the last copied stack info must be the first record");
      assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size,
             "the last copied frame info must be the last record");
    }