Function mi_win_virtual_allocx

3rd/mimalloc-2.0.9/src/os.c:401–428

#define MEM_COMMIT_RESERVE  (MEM_COMMIT|MEM_RESERVE)

static void* mi_win_virtual_allocx(void* addr, size_t size, size_t try_alignment, DWORD flags) {
#if (MI_INTPTR_SIZE >= 8)
  // on 64-bit systems, try to use the virtual address area after 2TiB for 4MiB aligned allocations
  if (addr == NULL) {
    void* hint = mi_os_get_aligned_hint(try_alignment,size);
    if (hint != NULL) {
      void* p = VirtualAlloc(hint, size, flags, PAGE_READWRITE);
      if (p != NULL) return p;
      _mi_verbose_message("warning: unable to allocate hinted aligned OS memory (%zu bytes, error code: 0x%x, address: %p, alignment: %zu, flags: 0x%x)\n", size, GetLastError(), hint, try_alignment, flags);
      // fall through on error
    }
  }
#endif
  // on modern Windows try use VirtualAlloc2 for aligned allocation
  if (try_alignment > 1 && (try_alignment % _mi_os_page_size()) == 0 && pVirtualAlloc2 != NULL) {
    MI_MEM_ADDRESS_REQUIREMENTS reqs = { 0, 0, 0 };
    reqs.Alignment = try_alignment;
    MI_MEM_EXTENDED_PARAMETER param = { {0, 0}, {0} };
    param.Type.Type = MiMemExtendedParameterAddressRequirements;
    param.Arg.Pointer = &reqs;
    void* p = (*pVirtualAlloc2)(GetCurrentProcess(), addr, size, flags, PAGE_READWRITE, &param, 1);
    if (p != NULL) return p;
    _mi_warning_message("unable to allocate aligned OS memory (%zu bytes, error code: 0x%x, address: %p, alignment: %zu, flags: 0x%x)\n", size, GetLastError(), addr, try_alignment, flags);
    // fall through on error
  }
  // last resort
  return VirtualAlloc(addr, size, flags, PAGE_READWRITE);
}

static void* mi_win_virtual_alloc(void* addr, size_t size, size_t try_alignment, DWORD flags, bool large_only, bool allow_large, bool* is_large) {
  mi_assert_internal(!(large_only && !allow_large));