diff options
| -rw-r--r-- | src/common/compat_libevent.c | 30 | ||||
| -rw-r--r-- | src/common/compat_libevent.h | 1 | ||||
| -rw-r--r-- | src/or/buffers.c | 2 | ||||
| -rw-r--r-- | src/or/circuitlist.c | 2 | ||||
| -rw-r--r-- | src/or/relay.c | 2 |
5 files changed, 34 insertions, 3 deletions
diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c index 6655ca87d3..77f8495e5c 100644 --- a/src/common/compat_libevent.c +++ b/src/common/compat_libevent.c @@ -724,3 +724,33 @@ tor_gettimeofday_cache_clear(void) } #endif +/** + * As tor_gettimeofday_cached, but can never move backwards in time. + * + * The returned value may diverge from wall-clock time, since wall-clock time + * can trivially be adjusted backwards, and this can't. Don't mix wall-clock + * time with these values in the same calculation. + * + * Depending on implementation, this function may or may not "smooth out" huge + * jumps forward in wall-clock time. It may or may not keep its results + * advancing forward (as opposed to stalling) if the wall-clock time goes + * backwards. The current implementation does neither of of these. + * + * This function is not thread-safe; do not call it outside the main thread. + * + * In future versions of Tor, this may return a time does not have its + * origin at the Unix epoch. + */ +void +tor_gettimeofday_cached_monotonic(struct timeval *tv) +{ + struct timeval last_tv = { 0, 0 }; + + tor_gettimeofday_cached(tv); + if (timercmp(tv, &last_tv, <)) { + memcpy(tv, &last_tv, sizeof(struct timeval)); + } else { + memcpy(&last_tv, tv, sizeof(struct timeval)); + } +} + diff --git a/src/common/compat_libevent.h b/src/common/compat_libevent.h index 56285ef80d..3190f13005 100644 --- a/src/common/compat_libevent.h +++ b/src/common/compat_libevent.h @@ -90,6 +90,7 @@ int tor_add_bufferevent_to_rate_limit_group(struct bufferevent *bev, void tor_gettimeofday_cached(struct timeval *tv); void tor_gettimeofday_cache_clear(void); +void tor_gettimeofday_cached_monotonic(struct timeval *tv); #endif diff --git a/src/or/buffers.c b/src/or/buffers.c index 352e60a979..b16ee6efa7 100644 --- a/src/or/buffers.c +++ b/src/or/buffers.c @@ -632,7 +632,7 @@ buf_add_chunk_with_capacity(buf_t *buf, size_t capacity, int capped) chunk = chunk_new_with_alloc_size(preferred_chunk_size(capacity)); } - tor_gettimeofday_cached(&now); + tor_gettimeofday_cached_monotonic(&now); chunk->inserted_time = (uint32_t)tv_to_msec(&now); if (buf->tail) { diff --git a/src/or/circuitlist.c b/src/or/circuitlist.c index 45fc95b561..0534e35553 100644 --- a/src/or/circuitlist.c +++ b/src/or/circuitlist.c @@ -1551,7 +1551,7 @@ circuits_handle_oom(size_t current_allocation) mem_to_recover = current_allocation - mem_target; } - tor_gettimeofday_cached(&now); + tor_gettimeofday_cached_monotonic(&now); now_ms = (uint32_t)tv_to_msec(&now); /* This algorithm itself assumes that you've got enough memory slack diff --git a/src/or/relay.c b/src/or/relay.c index e6d0f50aca..4cbc8fa471 100644 --- a/src/or/relay.c +++ b/src/or/relay.c @@ -1906,7 +1906,7 @@ cell_queue_append_packed_copy(cell_queue_t *queue, const cell_t *cell) { struct timeval now; packed_cell_t *copy = packed_cell_copy(cell); - tor_gettimeofday_cached(&now); + tor_gettimeofday_cached_monotonic(&now); copy->inserted_time = (uint32_t)tv_to_msec(&now); /* Remember the time when this cell was put in the queue. */ |