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-rw-r--r--src/or/routerlist.c91
1 files changed, 35 insertions, 56 deletions
diff --git a/src/or/routerlist.c b/src/or/routerlist.c
index 2149192509..dcf80a3aa8 100644
--- a/src/or/routerlist.c
+++ b/src/or/routerlist.c
@@ -67,7 +67,7 @@ typedef struct cert_list_t cert_list_t;
/* static function prototypes */
static int compute_weighted_bandwidths(const smartlist_t *sl,
bandwidth_weight_rule_t rule,
- u64_dbl_t **bandwidths_out);
+ double **bandwidths_out);
static const routerstatus_t *router_pick_trusteddirserver_impl(
const smartlist_t *sourcelist, dirinfo_type_t auth,
int flags, int *n_busy_out);
@@ -1815,20 +1815,23 @@ dirserver_choose_by_weight(const smartlist_t *servers, double authority_weight)
{
int n = smartlist_len(servers);
int i;
- u64_dbl_t *weights;
+ double *weights_dbl;
+ uint64_t *weights_u64;
const dir_server_t *ds;
- weights = tor_calloc(n, sizeof(u64_dbl_t));
+ weights_dbl = tor_calloc(n, sizeof(double));
+ weights_u64 = tor_calloc(n, sizeof(uint64_t));
for (i = 0; i < n; ++i) {
ds = smartlist_get(servers, i);
- weights[i].dbl = ds->weight;
+ weights_dbl[i] = ds->weight;
if (ds->is_authority)
- weights[i].dbl *= authority_weight;
+ weights_dbl[i] *= authority_weight;
}
- scale_array_elements_to_u64(weights, n, NULL);
- i = choose_array_element_by_weight(weights, n);
- tor_free(weights);
+ scale_array_elements_to_u64(weights_u64, weights_dbl, n, NULL);
+ i = choose_array_element_by_weight(weights_u64, n);
+ tor_free(weights_dbl);
+ tor_free(weights_u64);
return (i < 0) ? NULL : smartlist_get(servers, i);
}
@@ -2090,7 +2093,8 @@ router_get_advertised_bandwidth_capped(const routerinfo_t *router)
* much of the range of uint64_t. If <b>total_out</b> is provided, set it to
* the sum of all elements in the array _before_ scaling. */
STATIC void
-scale_array_elements_to_u64(u64_dbl_t *entries, int n_entries,
+scale_array_elements_to_u64(uint64_t *entries_out, const double *entries_in,
+ int n_entries,
uint64_t *total_out)
{
double total = 0.0;
@@ -2100,13 +2104,13 @@ scale_array_elements_to_u64(u64_dbl_t *entries, int n_entries,
#define SCALE_TO_U64_MAX ((int64_t) (INT64_MAX / 4))
for (i = 0; i < n_entries; ++i)
- total += entries[i].dbl;
+ total += entries_in[i];
if (total > 0.0)
scale_factor = SCALE_TO_U64_MAX / total;
for (i = 0; i < n_entries; ++i)
- entries[i].u64 = tor_llround(entries[i].dbl * scale_factor);
+ entries_out[i] = tor_llround(entries_in[i] * scale_factor);
if (total_out)
*total_out = (uint64_t) total;
@@ -2114,35 +2118,20 @@ scale_array_elements_to_u64(u64_dbl_t *entries, int n_entries,
#undef SCALE_TO_U64_MAX
}
-/** Time-invariant 64-bit greater-than; works on two integers in the range
- * (0,INT64_MAX). */
-#if SIZEOF_VOID_P == 8
-#define gt_i64_timei(a,b) ((a) > (b))
-#else
-static inline int
-gt_i64_timei(uint64_t a, uint64_t b)
-{
- int64_t diff = (int64_t) (b - a);
- int res = diff >> 63;
- return res & 1;
-}
-#endif
-
/** Pick a random element of <b>n_entries</b>-element array <b>entries</b>,
* choosing each element with a probability proportional to its (uint64_t)
* value, and return the index of that element. If all elements are 0, choose
* an index at random. Return -1 on error.
*/
STATIC int
-choose_array_element_by_weight(const u64_dbl_t *entries, int n_entries)
+choose_array_element_by_weight(const uint64_t *entries, int n_entries)
{
- int i, i_chosen=-1, n_chosen=0;
- uint64_t total_so_far = 0;
+ int i;
uint64_t rand_val;
uint64_t total = 0;
for (i = 0; i < n_entries; ++i)
- total += entries[i].u64;
+ total += entries[i];
if (n_entries < 1)
return -1;
@@ -2154,22 +2143,8 @@ choose_array_element_by_weight(const u64_dbl_t *entries, int n_entries)
rand_val = crypto_rand_uint64(total);
- for (i = 0; i < n_entries; ++i) {
- total_so_far += entries[i].u64;
- if (gt_i64_timei(total_so_far, rand_val)) {
- i_chosen = i;
- n_chosen++;
- /* Set rand_val to INT64_MAX rather than stopping the loop. This way,
- * the time we spend in the loop does not leak which element we chose. */
- rand_val = INT64_MAX;
- }
- }
- tor_assert(total_so_far == total);
- tor_assert(n_chosen == 1);
- tor_assert(i_chosen >= 0);
- tor_assert(i_chosen < n_entries);
-
- return i_chosen;
+ return select_array_member_cumulative_timei(
+ entries, n_entries, total, rand_val);
}
/** When weighting bridges, enforce these values as lower and upper
@@ -2221,17 +2196,21 @@ static const node_t *
smartlist_choose_node_by_bandwidth_weights(const smartlist_t *sl,
bandwidth_weight_rule_t rule)
{
- u64_dbl_t *bandwidths=NULL;
+ double *bandwidths_dbl=NULL;
+ uint64_t *bandwidths_u64=NULL;
- if (compute_weighted_bandwidths(sl, rule, &bandwidths) < 0)
+ if (compute_weighted_bandwidths(sl, rule, &bandwidths_dbl) < 0)
return NULL;
- scale_array_elements_to_u64(bandwidths, smartlist_len(sl), NULL);
+ bandwidths_u64 = tor_calloc(smartlist_len(sl), sizeof(uint64_t));
+ scale_array_elements_to_u64(bandwidths_u64, bandwidths_dbl,
+ smartlist_len(sl), NULL);
{
- int idx = choose_array_element_by_weight(bandwidths,
+ int idx = choose_array_element_by_weight(bandwidths_u64,
smartlist_len(sl));
- tor_free(bandwidths);
+ tor_free(bandwidths_dbl);
+ tor_free(bandwidths_u64);
return idx < 0 ? NULL : smartlist_get(sl, idx);
}
}
@@ -2244,14 +2223,14 @@ smartlist_choose_node_by_bandwidth_weights(const smartlist_t *sl,
static int
compute_weighted_bandwidths(const smartlist_t *sl,
bandwidth_weight_rule_t rule,
- u64_dbl_t **bandwidths_out)
+ double **bandwidths_out)
{
int64_t weight_scale;
double Wg = -1, Wm = -1, We = -1, Wd = -1;
double Wgb = -1, Wmb = -1, Web = -1, Wdb = -1;
uint64_t weighted_bw = 0;
guardfraction_bandwidth_t guardfraction_bw;
- u64_dbl_t *bandwidths;
+ double *bandwidths;
/* Can't choose exit and guard at same time */
tor_assert(rule == NO_WEIGHTING ||
@@ -2333,7 +2312,7 @@ compute_weighted_bandwidths(const smartlist_t *sl,
Web /= weight_scale;
Wdb /= weight_scale;
- bandwidths = tor_calloc(smartlist_len(sl), sizeof(u64_dbl_t));
+ bandwidths = tor_calloc(smartlist_len(sl), sizeof(double));
// Cycle through smartlist and total the bandwidth.
static int warned_missing_bw = 0;
@@ -2420,7 +2399,7 @@ compute_weighted_bandwidths(const smartlist_t *sl,
final_weight = weight*this_bw;
}
- bandwidths[node_sl_idx].dbl = final_weight + 0.5;
+ bandwidths[node_sl_idx] = final_weight + 0.5;
} SMARTLIST_FOREACH_END(node);
log_debug(LD_CIRC, "Generated weighted bandwidths for rule %s based "
@@ -2441,7 +2420,7 @@ double
frac_nodes_with_descriptors(const smartlist_t *sl,
bandwidth_weight_rule_t rule)
{
- u64_dbl_t *bandwidths = NULL;
+ double *bandwidths = NULL;
double total, present;
if (smartlist_len(sl) == 0)
@@ -2458,7 +2437,7 @@ frac_nodes_with_descriptors(const smartlist_t *sl,
total = present = 0.0;
SMARTLIST_FOREACH_BEGIN(sl, const node_t *, node) {
- const double bw = bandwidths[node_sl_idx].dbl;
+ const double bw = bandwidths[node_sl_idx];
total += bw;
if (node_has_descriptor(node))
present += bw;
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