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Diffstat (limited to 'malloc/tst-malloc-fork-deadlock.c')
| -rw-r--r-- | malloc/tst-malloc-fork-deadlock.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/malloc/tst-malloc-fork-deadlock.c b/malloc/tst-malloc-fork-deadlock.c new file mode 100644 index 0000000..94549ca --- /dev/null +++ b/malloc/tst-malloc-fork-deadlock.c @@ -0,0 +1,220 @@ +/* Test concurrent fork, getline, and fflush (NULL). + Copyright (C) 2016 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; see the file COPYING.LIB. If + not, see <http://www.gnu.org/licenses/>. */ + +#include <sys/wait.h> +#include <unistd.h> +#include <errno.h> +#include <stdio.h> +#include <pthread.h> +#include <stdbool.h> +#include <stdlib.h> +#include <malloc.h> +#include <time.h> +#include <string.h> +#include <signal.h> + +static int do_test (void); +#define TEST_FUNCTION do_test () +#include "../test-skeleton.c" + +enum { + /* Number of threads which call fork. */ + fork_thread_count = 4, + /* Number of threads which call getline (and, indirectly, + malloc). */ + read_thread_count = 8, +}; + +static bool termination_requested; + +static void * +fork_thread_function (void *closure) +{ + while (!__atomic_load_n (&termination_requested, __ATOMIC_RELAXED)) + { + pid_t pid = fork (); + if (pid < 0) + { + printf ("error: fork: %m\n"); + abort (); + } + else if (pid == 0) + _exit (17); + + int status; + if (waitpid (pid, &status, 0) < 0) + { + printf ("error: waitpid: %m\n"); + abort (); + } + if (!WIFEXITED (status) || WEXITSTATUS (status) != 17) + { + printf ("error: waitpid returned invalid status: %d\n", status); + abort (); + } + } + return NULL; +} + +static char *file_to_read; + +static void * +read_thread_function (void *closure) +{ + FILE *f = fopen (file_to_read, "r"); + if (f == NULL) + { + printf ("error: fopen (%s): %m\n", file_to_read); + abort (); + } + + while (!__atomic_load_n (&termination_requested, __ATOMIC_RELAXED)) + { + rewind (f); + char *line = NULL; + size_t line_allocated = 0; + ssize_t ret = getline (&line, &line_allocated, f); + if (ret < 0) + { + printf ("error: getline: %m\n"); + abort (); + } + free (line); + } + fclose (f); + + return NULL; +} + +static void * +flushall_thread_function (void *closure) +{ + while (!__atomic_load_n (&termination_requested, __ATOMIC_RELAXED)) + if (fflush (NULL) != 0) + { + printf ("error: fflush (NULL): %m\n"); + abort (); + } + return NULL; +} + +static void +create_threads (pthread_t *threads, size_t count, void *(*func) (void *)) +{ + for (size_t i = 0; i < count; ++i) + { + int ret = pthread_create (threads + i, NULL, func, NULL); + if (ret != 0) + { + errno = ret; + printf ("error: pthread_create: %m\n"); + abort (); + } + } +} + +static void +join_threads (pthread_t *threads, size_t count) +{ + for (size_t i = 0; i < count; ++i) + { + int ret = pthread_join (threads[i], NULL); + if (ret != 0) + { + errno = ret; + printf ("error: pthread_join: %m\n"); + abort (); + } + } +} + +/* Create a file which consists of a single long line, and assigns + file_to_read. The hope is that this triggers an allocation in + getline which needs a lock. */ +static void +create_file_with_large_line (void) +{ + int fd = create_temp_file ("bug19431-large-line", &file_to_read); + if (fd < 0) + { + printf ("error: create_temp_file: %m\n"); + abort (); + } + FILE *f = fdopen (fd, "w+"); + if (f == NULL) + { + printf ("error: fdopen: %m\n"); + abort (); + } + for (int i = 0; i < 50000; ++i) + fputc ('x', f); + fputc ('\n', f); + if (ferror (f)) + { + printf ("error: fputc: %m\n"); + abort (); + } + if (fclose (f) != 0) + { + printf ("error: fclose: %m\n"); + abort (); + } +} + +static int +do_test (void) +{ + /* Make sure that we do not exceed the arena limit with the number + of threads we configured. */ + if (mallopt (M_ARENA_MAX, 400) == 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 > TIMEOUT) + timeout = TIMEOUT - 1; + + create_file_with_large_line (); + + pthread_t fork_threads[fork_thread_count]; + create_threads (fork_threads, fork_thread_count, fork_thread_function); + pthread_t read_threads[read_thread_count]; + create_threads (read_threads, read_thread_count, read_thread_function); + pthread_t flushall_threads[1]; + create_threads (flushall_threads, 1, flushall_thread_function); + + struct timespec ts = {timeout, 0}; + if (nanosleep (&ts, NULL)) + { + printf ("error: error: nanosleep: %m\n"); + abort (); + } + + __atomic_store_n (&termination_requested, true, __ATOMIC_RELAXED); + + join_threads (flushall_threads, 1); + join_threads (read_threads, read_thread_count); + join_threads (fork_threads, fork_thread_count); + + free (file_to_read); + + return 0; +} |