WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
-
+
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+ SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
*/
#include "platform.h"
#include "gnunet_util_lib.h"
+#if __STDC_NO_ATOMICS__
+#define ATOMIC
+#else
+#ifdef HAVE_STDATOMIC_H
+#include <stdatomic.h>
+#define ATOMIC _Atomic
+#else
+#define __STDC_NO_ATOMICS__ 1
+#define ATOMIC
+#endif
+#endif
#define LOG(kind,...) GNUNET_log_from (kind, "util-time", __VA_ARGS__)
}
+/**
+ * Return a random time value between 0.5*r and 1.5*r.
+ *
+ * @param r input time for scaling
+ * @return randomized time
+ */
+struct GNUNET_TIME_Relative
+GNUNET_TIME_randomize (struct GNUNET_TIME_Relative r)
+{
+ double d = ((rand() % 1001) - 500) / 1000.0;
+
+ return relative_multiply_double (r,
+ d);
+}
+
+
/**
* Obtain the current time and make sure it is monotonically
* increasing. Guards against systems without an RTC or
* clocks running backwards and other nasty surprises. Does
* not guarantee that the returned time is near the current
- * time returned by #GNUNET_TIME_absolute_get(). Two
+ * time returned by #GNUNET_TIME_absolute_get(). Two
* subsequent calls (within a short time period) may return the
* same value. Persists the last returned time on disk to
* ensure that time never goes backwards. As a result, the
- * resulting value can be used to check if a message is the
+ * resulting value can be used to check if a message is the
* "most recent" value and replays of older messages (from
* the same origin) would be discarded.
- *
- * @param cfg configuration, used to determine where to
+ *
+ * @param cfg configuration, used to determine where to
* store the time; user can also insist RTC is working
* nicely and disable the feature
* @return monotonically increasing time
static const struct GNUNET_CONFIGURATION_Handle *last_cfg;
static struct GNUNET_TIME_Absolute last_time;
static struct GNUNET_DISK_MapHandle *map_handle;
- static struct GNUNET_TIME_AbsoluteNBO *map;
+ static ATOMIC volatile uint64_t *map;
struct GNUNET_TIME_Absolute now;
now = GNUNET_TIME_absolute_get ();
map_handle = NULL;
}
map = NULL;
-
+
last_cfg = cfg;
if ( (NULL != cfg) &&
(GNUNET_OK ==
struct GNUNET_DISK_FileHandle *fh;
fh = GNUNET_DISK_file_open (filename,
- GNUNET_DISK_OPEN_READWRITE | GNUNET_DISK_OPEN_CREATE,
- GNUNET_DISK_PERM_USER_WRITE | GNUNET_DISK_PERM_GROUP_WRITE |
- GNUNET_DISK_PERM_USER_READ | GNUNET_DISK_PERM_GROUP_READ);
+ GNUNET_DISK_OPEN_READWRITE | GNUNET_DISK_OPEN_CREATE,
+ GNUNET_DISK_PERM_USER_WRITE | GNUNET_DISK_PERM_GROUP_WRITE |
+ GNUNET_DISK_PERM_USER_READ | GNUNET_DISK_PERM_GROUP_READ);
if (NULL == fh)
{
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("Failed to map `%s', cannot assure monotonic time!\n"),
- filename);
+ GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+ _("Failed to map `%s', cannot assure monotonic time!\n"),
+ filename);
}
else
- {
- off_t size;
-
- size = 0;
- GNUNET_break (GNUNET_OK ==
- GNUNET_DISK_file_handle_size (fh,
- &size));
- if (size < sizeof (*map))
- {
- struct GNUNET_TIME_AbsoluteNBO o;
-
- o = GNUNET_TIME_absolute_hton (now);
- if (sizeof (o) !=
- GNUNET_DISK_file_write (fh,
- &o,
- sizeof (o)))
- size = 0;
- else
- size = sizeof (o);
- }
- if (size == sizeof (*map))
- {
- map = GNUNET_DISK_file_map (fh,
- &map_handle,
- GNUNET_DISK_MAP_TYPE_READWRITE,
- sizeof (*map));
- if (NULL == map)
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("Failed to map `%s', cannot assure monotonic time!\n"),
- filename);
- }
- else
- {
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("Failed to setup monotonic time file `%s', cannot assure monotonic time!\n"),
- filename);
- }
+ {
+ off_t size;
+
+ size = 0;
+ GNUNET_break (GNUNET_OK ==
+ GNUNET_DISK_file_handle_size (fh,
+ &size));
+ if (size < (off_t) sizeof (*map))
+ {
+ struct GNUNET_TIME_AbsoluteNBO o;
+
+ o = GNUNET_TIME_absolute_hton (now);
+ if (sizeof (o) !=
+ GNUNET_DISK_file_write (fh,
+ &o,
+ sizeof (o)))
+ size = 0;
+ else
+ size = sizeof (o);
+ }
+ if (size == sizeof (*map))
+ {
+ map = GNUNET_DISK_file_map (fh,
+ &map_handle,
+ GNUNET_DISK_MAP_TYPE_READWRITE,
+ sizeof (*map));
+ if (NULL == map)
+ GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+ _("Failed to map `%s', cannot assure monotonic time!\n"),
+ filename);
+ }
+ else
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+ _("Failed to setup monotonic time file `%s', cannot assure monotonic time!\n"),
+ filename);
+ }
}
GNUNET_DISK_file_close (fh);
GNUNET_free (filename);
}
}
if (NULL != map)
- last_time = GNUNET_TIME_absolute_max (GNUNET_TIME_absolute_ntoh (*map),
+ {
+ struct GNUNET_TIME_AbsoluteNBO mt;
+
+#if __STDC_NO_ATOMICS__
+#if __GNUC__
+ mt.abs_value_us__ = __sync_fetch_and_or (map, 0);
+#else
+ mt.abs_value_us__ = *map; /* godspeed, pray this is atomic */
+#endif
+#else
+ mt.abs_value_us__ = atomic_load (map);
+#endif
+ last_time = GNUNET_TIME_absolute_max (GNUNET_TIME_absolute_ntoh (mt),
last_time);
+ }
if (now.abs_value_us <= last_time.abs_value_us)
now.abs_value_us = last_time.abs_value_us+1;
last_time = now;
if (NULL != map)
- *map = GNUNET_TIME_absolute_hton (now);
+ {
+ uint64_t val = GNUNET_TIME_absolute_hton (now).abs_value_us__;
+#if __STDC_NO_ATOMICS__
+#if __GNUC__
+ (void) __sync_lock_test_and_set (map, val);
+#else
+ *map = val; /* godspeed, pray this is atomic */
+#endif
+#else
+ atomic_store (map,
+ val);
+#endif
+ }
return now;
}
projects / oweals / gnunet.git / blobdiff