39   void* const handle = os::dll_load(library, ebuf, sizeof(ebuf));
  40   if (handle == NULL) {
  41     log_error(gc)("Failed to load library: %s", library);
  42     vm_exit_during_initialization("ZGC requires Windows version 1803 or later");
  43   }
  44 
  45   fn = reinterpret_cast<Fn*>(os::dll_lookup(handle, symbol));
  46   if (fn == NULL) {
  47     log_error(gc)("Failed to lookup symbol: %s", symbol);
  48     vm_exit_during_initialization("ZGC requires Windows version 1803 or later");
  49   }
  50 }
  51 
  52 void ZSyscall::initialize() {
  53   lookup_symbol(CreateFileMappingW, "KernelBase", "CreateFileMappingW");
  54   lookup_symbol(VirtualAlloc2,      "KernelBase", "VirtualAlloc2");
  55   lookup_symbol(VirtualFreeEx,      "KernelBase", "VirtualFreeEx");
  56   lookup_symbol(MapViewOfFile3,     "KernelBase", "MapViewOfFile3");
  57   lookup_symbol(UnmapViewOfFile2,   "KernelBase", "UnmapViewOfFile2");
  58 }

  39   void* const handle = os::dll_load(library, ebuf, sizeof(ebuf));
  40   if (handle == NULL) {
  41     log_error(gc)("Failed to load library: %s", library);
  42     vm_exit_during_initialization("ZGC requires Windows version 1803 or later");
  43   }
  44 
  45   fn = reinterpret_cast<Fn*>(os::dll_lookup(handle, symbol));
  46   if (fn == NULL) {
  47     log_error(gc)("Failed to lookup symbol: %s", symbol);
  48     vm_exit_during_initialization("ZGC requires Windows version 1803 or later");
  49   }
  50 }
  51 
  52 void ZSyscall::initialize() {
  53   lookup_symbol(CreateFileMappingW, "KernelBase", "CreateFileMappingW");
  54   lookup_symbol(VirtualAlloc2,      "KernelBase", "VirtualAlloc2");
  55   lookup_symbol(VirtualFreeEx,      "KernelBase", "VirtualFreeEx");
  56   lookup_symbol(MapViewOfFile3,     "KernelBase", "MapViewOfFile3");
  57   lookup_symbol(UnmapViewOfFile2,   "KernelBase", "UnmapViewOfFile2");
  58 }
  59 
  60 bool ZSyscall::is_os_supported() {
  61   char ebuf[1024];
  62   void* const handle = os::dll_load("KernelBase", ebuf, sizeof(ebuf));
  63   if (handle == NULL) {
  64     assert(false, "Failed to load library: KernelBase");
  65     return false;
  66   }
  67 
  68   return os::dll_lookup(handle, "VirtualAlloc2") != NULL;
  69 }