1  /* Test support for single-thread optimizations.  No threads, static dlopen.
       2     Copyright (C) 2020-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  /* In a static dlopen scenario, the single-threaded optimization is
      20     not possible because their is no globally shared dynamic linker
      21     across all namespaces.  */
      22  
      23  #include <stddef.h>
      24  #include <support/check.h>
      25  #include <support/xdlfcn.h>
      26  #include <sys/single_threaded.h>
      27  
      28  static int
      29  do_test (void)
      30  {
      31    TEST_VERIFY (__libc_single_threaded);
      32  
      33    /* Defined in tst-single-threaded-mod1.o.  */
      34    extern _Bool single_threaded_1 (void);
      35    TEST_VERIFY (single_threaded_1 ());
      36  
      37    /* A failed dlopen does not change the multi-threaded status.  */
      38    TEST_VERIFY (dlopen ("tst-single_threaded-does-not-exist.so", RTLD_LAZY)
      39                 == NULL);
      40    TEST_VERIFY (__libc_single_threaded);
      41    TEST_VERIFY (single_threaded_1 ());
      42  
      43    /* And neither does a successful dlopen for outer (static) libc.  */
      44    void *handle_mod2 = xdlopen ("tst-single_threaded-mod2.so", RTLD_LAZY);
      45    _Bool (*single_threaded_2) (void)
      46      = xdlsym (handle_mod2, "single_threaded_2");
      47    TEST_VERIFY (__libc_single_threaded);
      48    TEST_VERIFY (single_threaded_1 ());
      49    /* The inner libc always assumes multi-threaded use.  */
      50    TEST_VERIFY (!single_threaded_2 ());
      51  
      52    xdlclose (handle_mod2);
      53  
      54    return 0;
      55  }
      56  
      57  #include <support/test-driver.c>