1 files changed, 112 insertions, 0 deletions
diff --git a/src/tests/fspause.c b/src/tests/fspause.c
new file mode 100644
index 0000000..092fbb4
--- /dev/null
+++ b/src/tests/fspause.c
@@ -0,0 +1,112 @@
+/*
+ * 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 "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 _GL_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;
+}