| /* Bug 22111: Test that threads do not leak their per thread cache. |
| 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 |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* The point of this test is to start and exit a large number of |
| threads, while at the same time looking to see if the used |
| memory grows with each round of threads run. If the memory |
| grows above some linear bound we declare the test failed and |
| that the malloc implementation is leaking memory with each |
| thread. This is a good indicator that the thread local cache |
| is leaking chunks. */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <malloc.h> |
| #include <pthread.h> |
| #include <assert.h> |
| |
| #include <support/check.h> |
| #include <support/support.h> |
| #include <support/xthread.h> |
| |
| void * |
| worker (void *data) |
| { |
| void *ret; |
| /* Allocate an arbitrary amount of memory that is known to fit into |
| the thread local cache (tcache). If we have at least 64 bins |
| (default e.g. TCACHE_MAX_BINS) we should be able to allocate 32 |
| bytes and force malloc to fill the tcache. We are assuming tcahce |
| init happens at the first small alloc, but it might in the future |
| be deferred to some other point. Therefore to future proof this |
| test we include a full alloc/free/alloc cycle for the thread. We |
| need a compiler barrier to avoid the removal of the useless |
| alloc/free. We send some memory back to main to have the memory |
| freed after the thread dies, as just another check that the chunks |
| that were previously in the tcache are still OK to free after |
| thread death. */ |
| ret = xmalloc (32); |
| __asm__ volatile ("" ::: "memory"); |
| free (ret); |
| return (void *) xmalloc (32); |
| } |
| |
| static int |
| do_test (void) |
| { |
| pthread_t *thread; |
| struct mallinfo info_before, info_after; |
| void *retval; |
| |
| /* This is an arbitrary choice. We choose a total of THREADS |
| threads created and joined. This gives us enough iterations to |
| show a leak. */ |
| int threads = 100000; |
| |
| /* Avoid there being 0 malloc'd data at this point by allocating the |
| pthread_t required to run the test. */ |
| thread = (pthread_t *) xcalloc (1, sizeof (pthread_t)); |
| |
| info_before = mallinfo (); |
| |
| assert (info_before.uordblks != 0); |
| |
| printf ("INFO: %d (bytes) are in use before starting threads.\n", |
| info_before.uordblks); |
| |
| for (int loop = 0; loop < threads; loop++) |
| { |
| *thread = xpthread_create (NULL, worker, NULL); |
| retval = xpthread_join (*thread); |
| free (retval); |
| } |
| |
| info_after = mallinfo (); |
| printf ("INFO: %d (bytes) are in use after all threads joined.\n", |
| info_after.uordblks); |
| |
| /* We need to compare the memory in use before and the memory in use |
| after starting and joining THREADS threads. We almost always grow |
| memory slightly, but not much. Consider that if even 1-byte leaked |
| per thread we'd have THREADS bytes of additional memory, and in |
| general the in-use at the start of main is quite low. We will |
| always leak a full malloc chunk, and never just 1-byte, therefore |
| anything above "+ threads" from the start (constant offset) is a |
| leak. Obviously this assumes no thread-related malloc'd internal |
| libc data structures persist beyond the thread death, and any that |
| did would limit the number of times you could call pthread_create, |
| which is a QoI we'd want to detect and fix. */ |
| if (info_after.uordblks > (info_before.uordblks + threads)) |
| FAIL_EXIT1 ("Memory usage after threads is too high.\n"); |
| |
| /* Did not detect excessive memory usage. */ |
| free (thread); |
| exit (0); |
| } |
| |
| #define TIMEOUT 50 |
| #include <support/test-driver.c> |