os::free(void *memblock)

• 引数で渡されたメモリ領域を解放する

//(jdk7/hotspot/src/share/vm/runtime/os.cpp)
void  os::free(void *memblock) {
  NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
#ifdef ASSERT
  if (memblock == NULL) return;
  if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
    if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
    breakpoint();
  }
  verify_block(memblock);
  NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
  // Added by detlefs.
  if (MallocCushion) {
    u_char* ptr = (u_char*)memblock - space_before;
    for (u_char* p = ptr; p < ptr + MallocCushion; p++) {
      guarantee(*p == badResourceValue,
                "Thing freed should be malloc result.");
      *p = (u_char)freeBlockPad;
    }
    size_t size = get_size(memblock);
    inc_stat_counter(&free_bytes, size);
    u_char* end = ptr + space_before + size;
    for (u_char* q = end; q < end + MallocCushion; q++) {
      guarantee(*q == badResourceValue,
                "Thing freed should be malloc result.");
      *q = (u_char)freeBlockPad;
    }
    if (PrintMalloc && tty != NULL)
      fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
  } else if (PrintMalloc && tty != NULL) {
    // tty->print_cr("os::free %p", memblock);
    fprintf(stderr, "os::free " PTR_FORMAT "\n", (uintptr_t)memblock);
  }
#endif

  //glibcのfree関数を呼び出す
  //free関数 http://linuxjm.sourceforge.jp/html/LDP_man-pages/man3/free.3.html
  ::free((char*)memblock - space_before);
}