/* Test malloc with concurrent thread termination. Copyright (C) 2015-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see . */ /* This thread spawns a number of outer threads, equal to the arena limit. The outer threads run a loop which start and join two different kinds of threads: the first kind allocates (attaching an arena to the thread; malloc_first_thread) and waits, the second kind waits and allocates (wait_first_threads). Both kinds of threads exit immediately after waiting. The hope is that this will exhibit races in thread termination and arena management, particularly related to the arena free list. */ #include #include #include #include #include #include #include #include #include #include static bool termination_requested; static int inner_thread_count = 4; static size_t malloc_size = 32; static void __attribute__ ((noinline, noclone)) unoptimized_free (void *ptr) { free (ptr); } static void * malloc_first_thread (void * closure) { pthread_barrier_t *barrier = closure; void *ptr = xmalloc (malloc_size); xpthread_barrier_wait (barrier); unoptimized_free (ptr); return NULL; } static void * wait_first_thread (void * closure) { pthread_barrier_t *barrier = closure; xpthread_barrier_wait (barrier); void *ptr = xmalloc (malloc_size); unoptimized_free (ptr); return NULL; } static void * outer_thread (void *closure) { pthread_t *threads = xcalloc (sizeof (*threads), inner_thread_count); while (!__atomic_load_n (&termination_requested, __ATOMIC_RELAXED)) { pthread_barrier_t barrier; xpthread_barrier_init (&barrier, NULL, inner_thread_count + 1); for (int i = 0; i < inner_thread_count; ++i) { void *(*func) (void *); if ((i % 2) == 0) func = malloc_first_thread; else func = wait_first_thread; threads[i] = xpthread_create (NULL, func, &barrier); } xpthread_barrier_wait (&barrier); for (int i = 0; i < inner_thread_count; ++i) xpthread_join (threads[i]); xpthread_barrier_destroy (&barrier); } free (threads); return NULL; } static int do_test (void) { /* The number of threads should be smaller than the number of arenas, so that there will be some free arenas to add to the arena free list. */ enum { outer_thread_count = 2 }; if (mallopt (M_ARENA_MAX, 8) == 0) { printf ("error: mallopt (M_ARENA_MAX) failed\n"); return 1; } /* Leave some room for shutting down all threads gracefully. */ int timeout = 3; if (timeout > DEFAULT_TIMEOUT) timeout = DEFAULT_TIMEOUT - 1; pthread_t *threads = xcalloc (sizeof (*threads), outer_thread_count); for (long i = 0; i < outer_thread_count; ++i) threads[i] = xpthread_create (NULL, outer_thread, NULL); struct timespec ts = {timeout, 0}; if (nanosleep (&ts, NULL)) { printf ("error: error: nanosleep: %m\n"); abort (); } __atomic_store_n (&termination_requested, true, __ATOMIC_RELAXED); for (long i = 0; i < outer_thread_count; ++i) xpthread_join (threads[i]); free (threads); return 0; } #include