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Diffstat (limited to 'src/tests/fspause.c')
-rw-r--r-- | src/tests/fspause.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/src/tests/fspause.c b/src/tests/fspause.c new file mode 100644 index 0000000..4f573c6 --- /dev/null +++ b/src/tests/fspause.c @@ -0,0 +1,113 @@ +/* + * fspause.c: pause until a file timestamp updates + * + * Copyright (C) 2014 Colin Watson. + * + * This file is part of man-db. + * + * man-db is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * man-db 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with man-db; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif /* HAVE_CONFIG_H */ + +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <time.h> +#include <unistd.h> + +#include "attribute.h" +#include "progname.h" +#include "stat-time.h" +#include "timespec.h" +#include "xalloc.h" + +#include "manconfig.h" + +static char *filename; +static int fd = -1; + +#define MUST(name, cond) \ + do { \ + if (!(cond)) { \ + fprintf (stderr, "fspause: " name " failed\n"); \ + abort (); \ + } \ + } while (0) + +static void unlink_tempfile (void) +{ + if (fd >= 0) { + MUST ("close", close (fd) >= 0); + MUST ("unlink", unlink (filename) >= 0); + } +} + +static void delay (int delay_ns) +{ + struct timespec delay_ts; + + delay_ts.tv_sec = delay_ns / 1000000000; + delay_ts.tv_nsec = delay_ns % 1000000000; + for (;;) { + errno = 0; + if (nanosleep (&delay_ts, NULL) == 0) + break; + MUST ("nanosleep", errno == 0 || errno == EINTR); + } +} + +static int try_delay (struct stat *st, int delay_ns) +{ + struct timespec start_ts, end_ts; + + start_ts = get_stat_mtime (st); + delay (delay_ns); + MUST ("write", write (fd, "\n", 1) == 1); + MUST ("fstat", fstat (fd, st) >= 0); + end_ts = get_stat_mtime (st); + return timespec_cmp (start_ts, end_ts) != 0; +} + +int main (int argc MAYBE_UNUSED, char **argv) +{ + struct stat st; + int delay_ns; + + set_program_name (argv[0]); + + filename = xstrdup ("fspause.tmp.XXXXXX"); + MUST ("mkstemp", (fd = mkstemp (filename)) >= 0); + atexit (unlink_tempfile); + MUST ("fstat", fstat (fd, &st) >= 0); + + /* 0x40000000 nanoseconds is just over a second. The effective + * maximum delay we will allow is thus about two seconds. This + * saves us having to keep track of anything more complicated than a + * single signed 32-bit int. + */ + for (delay_ns = 1; delay_ns < 0x40000000; delay_ns *= 2) { + if (try_delay (&st, delay_ns)) + return 0; + } + + fprintf (stderr, + "fspause: temporary file timestamp refuses to change!\n"); + return 1; +} |