Line data Source code
1 : #include "fd_sysvar_clock.h"
2 : #include "fd_sysvar_epoch_schedule.h"
3 : #include "../fd_runtime_stack.h"
4 : #include "../fd_system_ids.h"
5 : #include "../sysvar/fd_sysvar.h"
6 :
7 : /* Syvar Clock Possible Values:
8 : slot:
9 : [0, ULONG_MAX]
10 :
11 : epoch:
12 : [0, slot/432000UL]
13 :
14 : epoch_start_timestamp:
15 : [0, ULONG_MAX]
16 :
17 : unix_timestamp:
18 : This value is bounded by the slot distance from the
19 : epoch_start_timestamp.
20 : The protocol allows for a maximum drift (either fast or slow) from the
21 : start of the epoch's timestamp. The expected time is called the PoH
22 : offset. This offset is calculated by (epoch_start_timestamp + slots
23 : since epoch * slot_duration). The drift is then bounded by the
24 : max_allowable_drift_{slow,fast}. The stake weighted offset can be
25 : 150% more than the PoH offset and 25% less than the PoH offset.
26 : So, the bounds for the unix_timestamp can be calculated by:
27 : upper bound = epoch_start_timestamp + (slots since epoch * slot_duration) * 2.5
28 : lower bound = epoch_start_timestamp + (slots since epoch * slot_duration) * 0.75
29 :
30 : leader_schedule_epoch:
31 : This is the value of the epoch used for the leader schedule. It is
32 : computed based on the values of the epoch schedule (first_normal_slot,
33 : leader_schedule_slot_offset, slots_per_epoch). It is always equal to
34 : ((slot - first_normal_slot) + leader_schedule_slot_offset) / schedule->slots_per_epoch
35 : */
36 :
37 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L14 */
38 4041 : #define MAX_ALLOWABLE_DRIFT_FAST_PERCENT ( 25U )
39 :
40 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L15 */
41 4041 : #define MAX_ALLOWABLE_DRIFT_SLOW_PERCENT ( 150U )
42 :
43 : /* Do all intermediate calculations at nanosecond precision, to mirror
44 : Solana's behavior. */
45 15615 : #define NS_IN_S ((long)1e9)
46 :
47 : /* FD_SYSVAR_CLOCK_STAKE_WEIGHTS_MAX specifies the max number of stake
48 : weights processed in a clock update. */
49 :
50 : #define FD_SYSVAR_CLOCK_STAKE_WEIGHTS_MAX (10240UL)
51 :
52 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2110-L2117 */
53 : static inline long
54 6 : unix_timestamp_from_genesis( fd_bank_t * bank ) {
55 : /* TODO: genesis_creation_time needs to be a long in the bank. */
56 6 : return fd_long_sat_add(
57 6 : (long)bank->f.genesis_creation_time,
58 6 : (long)( fd_uint128_sat_mul( bank->f.slot, bank->f.slot_params.ns_per_slot ) / NS_IN_S ) );
59 6 : }
60 :
61 : static void
62 : fd_sysvar_clock_write( fd_bank_t * bank,
63 : fd_accdb_t * accdb,
64 : fd_capture_ctx_t * capture_ctx,
65 4476 : fd_sol_sysvar_clock_t const * clock ) {
66 4476 : fd_sysvar_account_update( bank, accdb, capture_ctx, &fd_sysvar_clock_id, clock, sizeof(fd_sol_sysvar_clock_t) );
67 4476 : }
68 :
69 : fd_sol_sysvar_clock_t *
70 : fd_sysvar_clock_read( fd_accdb_t * accdb,
71 : fd_accdb_fork_id_t fork_id,
72 4485 : fd_sol_sysvar_clock_t * clock ) {
73 4485 : fd_acc_t acc = fd_accdb_read_one( accdb, fork_id, fd_sysvar_clock_id.uc );
74 4485 : if( FD_UNLIKELY( !acc.lamports || acc.data_len<sizeof(fd_sol_sysvar_clock_t) ) ) {
75 : /* This check is needed as a quirk of the fuzzer. If a sysvar
76 : account exists in the accounts database, but doesn't have any
77 : lamports, this means that the account does not exist. This
78 : wouldn't happen in a real execution environment. */
79 0 : fd_accdb_unread_one( accdb, &acc );
80 0 : return NULL;
81 0 : }
82 :
83 4485 : fd_memcpy( clock, acc.data, sizeof(fd_sol_sysvar_clock_t) );
84 4485 : fd_accdb_unread_one( accdb, &acc );
85 4485 : return clock;
86 4485 : }
87 :
88 : void
89 : fd_sysvar_clock_init( fd_bank_t * bank,
90 : fd_accdb_t * accdb,
91 6 : fd_capture_ctx_t * capture_ctx ) {
92 6 : long timestamp = unix_timestamp_from_genesis( bank );
93 :
94 6 : fd_sol_sysvar_clock_t clock = {
95 6 : .slot = bank->f.slot,
96 6 : .epoch = 0,
97 6 : .epoch_start_timestamp = timestamp,
98 6 : .leader_schedule_epoch = 1,
99 6 : .unix_timestamp = timestamp,
100 6 : };
101 6 : fd_sysvar_clock_write( bank, accdb, capture_ctx, &clock );
102 6 : }
103 :
104 : #define SORT_NAME sort_stake_ts
105 534 : #define SORT_KEY_T ts_est_ele_t
106 267 : #define SORT_BEFORE(a,b) ( (a).timestamp < (b).timestamp )
107 : #include "../../../util/tmpl/fd_sort.c"
108 :
109 : static void
110 : accum_vote_stakes( fd_bank_t * bank,
111 : fd_runtime_stack_t * runtime_stack,
112 : uint128 * total_stake_out,
113 4470 : ulong * ts_ele_cnt_out ) {
114 :
115 4470 : ts_est_ele_t * ts_eles = runtime_stack->clock_ts.staked_ts;
116 4470 : ulong ts_ele_cnt = 0UL;
117 :
118 4470 : uint128 total_stake = 0UL;
119 :
120 4470 : fd_epoch_schedule_t const * epoch_schedule = &bank->f.epoch_schedule;
121 4470 : ulong current_slot = bank->f.slot;
122 :
123 4470 : fd_vote_stakes_t * vote_stakes = fd_bank_vote_stakes( bank );
124 4470 : ulong fork_id = bank->vote_stakes_fork_id;
125 :
126 4470 : uchar __attribute__((aligned(FD_VOTE_STAKES_T_2_ITER_ALIGN))) iter_mem[ FD_VOTE_STAKES_T_2_ITER_FOOTPRINT ];
127 4470 : for( fd_vote_stakes_t_2_iter_t * iter = fd_vote_stakes_t_2_iter_init( vote_stakes, fork_id, iter_mem );
128 9567 : !fd_vote_stakes_t_2_iter_done( vote_stakes, fork_id, iter );
129 5097 : fd_vote_stakes_t_2_iter_next( vote_stakes, fork_id, iter ) ) {
130 5097 : fd_pubkey_t pubkey;
131 5097 : ulong stake_t_2;
132 5097 : ulong last_vote_slot;
133 5097 : long last_vote_timestamp;
134 5097 : uchar is_valid;
135 5097 : fd_vote_stakes_t_2_iter_ele( vote_stakes, fork_id, iter, &pubkey, NULL, &stake_t_2, &last_vote_slot, &last_vote_timestamp, NULL, &is_valid, NULL );
136 5097 : if( FD_UNLIKELY( !is_valid ) ) continue;
137 :
138 : /* https://github.com/anza-xyz/agave/blob/v3.0.0/runtime/src/bank.rs#L2445 */
139 4911 : if( FD_UNLIKELY( current_slot<last_vote_slot ) ) {
140 : /* Don't count vote accounts with a last vote slot that is greater
141 : than the current slot. */
142 0 : continue;
143 0 : }
144 4911 : ulong slot_delta = current_slot-last_vote_slot;
145 :
146 : /* Don't count vote accounts that haven't voted in the past 432k
147 : slots (length of an epoch).
148 : https://github.com/anza-xyz/agave/blob/v3.0.0/runtime/src/bank.rs#L2446-L2447 */
149 4911 : if( FD_UNLIKELY( slot_delta>epoch_schedule->slots_per_epoch ) ) {
150 603 : continue;
151 603 : }
152 :
153 : /* Calculate the timestamp estimate by taking the last vote
154 : timestamp and adding the estimated time since the last vote
155 : (delta from last vote slot to current slot * slot duration).
156 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L44-L45 */
157 4308 : ulong offset = fd_slot_params_slot_range_duration_ns( bank, last_vote_slot+1UL, current_slot+1UL );
158 4308 : long estimate = fd_long_sat_add( last_vote_timestamp, (long)(offset / NS_IN_S) );
159 :
160 : /* For each timestamp, accumulate the stake from E-2. If the entry
161 : for the timestamp doesn't exist yet, insert it. Otherwise,
162 : update the existing entry.
163 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L46-L53 */
164 4308 : ts_eles[ ts_ele_cnt ] = (ts_est_ele_t){
165 4308 : .timestamp = estimate,
166 4308 : .stake = { .ud=stake_t_2 },
167 4308 : };
168 4308 : ts_ele_cnt++;
169 :
170 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L54 */
171 4308 : total_stake += stake_t_2;
172 4308 : }
173 :
174 4470 : *total_stake_out = total_stake;
175 4470 : *ts_ele_cnt_out = ts_ele_cnt;
176 4470 : }
177 :
178 : /* get_timestamp_estimate calculates a timestamp estimate. Does not
179 : modify the slot context. Walks all cached vote accounts (from the
180 : "bank") and calculates a unix timestamp estimate. Returns the
181 : timestamp estimate. spad is used for scratch allocations (allocates
182 : a treap of size FD_SYSVAR_CLOCK_STAKE_WEIGHTS_MAX). Crashes the
183 : process with FD_LOG_ERR on failure (e.g. too many vote accounts).
184 :
185 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2563-L2601 */
186 : static long
187 : get_timestamp_estimate( fd_bank_t * bank,
188 : fd_sol_sysvar_clock_t * clock,
189 : fd_runtime_stack_t * runtime_stack,
190 : ulong const * parent_epoch,
191 4470 : int * out_estimate_present ) {
192 4470 : fd_epoch_schedule_t const * epoch_schedule = &bank->f.epoch_schedule;
193 4470 : ulong current_slot = bank->f.slot;
194 :
195 4470 : ts_est_ele_t * ts_eles = runtime_stack->clock_ts.staked_ts;
196 :
197 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L41 */
198 4470 : ulong ts_ele_cnt = 0UL;
199 4470 : uint128 total_stake = 0UL;
200 :
201 : /* A timestamp estimate is calculated at every slot using the most
202 : recent vote states of voting validators. This estimated is based on
203 : a stake weighted median using the stake as of the end of epoch E-2
204 : if we are currently in epoch E. We do not count vote accounts that
205 : have not voted in an epoch's worth of slots (432k). */
206 :
207 4470 : ulong curr_epoch = fd_slot_to_epoch( epoch_schedule, bank->f.slot, NULL );
208 :
209 4470 : accum_vote_stakes( bank, runtime_stack, &total_stake, &ts_ele_cnt );
210 :
211 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L56-L58 */
212 4470 : if( FD_UNLIKELY( total_stake==0UL ) ) {
213 429 : *out_estimate_present = 0;
214 429 : return 0L;
215 429 : }
216 :
217 4041 : sort_stake_ts_inplace( ts_eles, ts_ele_cnt );
218 :
219 : /* Populate estimate with the stake-weighted median timestamp.
220 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L59-L68 */
221 4041 : uint128 stake_accumulator = 0;
222 4041 : long estimate = 0L;
223 4308 : for( ulong i=0UL; i<ts_ele_cnt; i++ ) {
224 4308 : stake_accumulator = fd_uint128_sat_add( stake_accumulator, ts_eles[i].stake.ud );
225 4308 : if( stake_accumulator>(total_stake/2UL) ) {
226 4041 : estimate = ts_eles[ i ].timestamp;
227 4041 : break;
228 4041 : }
229 4308 : }
230 :
231 : /* Bound estimate by `max_allowable_drift` since the start of the
232 : epoch.
233 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L69-L99 */
234 4041 : ulong epoch_for_start_slot = parent_epoch ? *parent_epoch : curr_epoch;
235 4041 : ulong epoch_start_slot = fd_epoch_slot0( epoch_schedule, epoch_for_start_slot );
236 4041 : long epoch_start_timestamp = clock->epoch_start_timestamp;
237 :
238 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L71-L72 */
239 4041 : ulong poh_estimate_offset = fd_slot_params_slot_range_duration_ns( bank, epoch_start_slot+1UL, current_slot+1UL );
240 :
241 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L73-L77 */
242 4041 : ulong estimate_offset = fd_ulong_sat_mul( NS_IN_S, fd_ulong_sat_sub( (ulong)estimate, (ulong)epoch_start_timestamp ) );
243 :
244 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L78-L81 */
245 4041 : ulong max_allowable_drift_fast = fd_ulong_sat_mul( poh_estimate_offset, MAX_ALLOWABLE_DRIFT_FAST_PERCENT ) / 100UL;
246 4041 : ulong max_allowable_drift_slow = fd_ulong_sat_mul( poh_estimate_offset, MAX_ALLOWABLE_DRIFT_SLOW_PERCENT ) / 100UL;
247 :
248 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L82-L98 */
249 4041 : if( estimate_offset>poh_estimate_offset && fd_ulong_sat_sub( estimate_offset, poh_estimate_offset )>max_allowable_drift_slow ) {
250 72 : estimate = fd_long_sat_add(
251 72 : epoch_start_timestamp,
252 72 : fd_long_sat_add( (long)poh_estimate_offset / NS_IN_S, (long)max_allowable_drift_slow / NS_IN_S ) );
253 3969 : } else if( estimate_offset<poh_estimate_offset && fd_ulong_sat_sub( poh_estimate_offset, estimate_offset )>max_allowable_drift_fast ) {
254 3558 : estimate = fd_long_sat_sub(
255 3558 : fd_long_sat_add( epoch_start_timestamp, (long)poh_estimate_offset / NS_IN_S ),
256 3558 : (long)max_allowable_drift_fast / NS_IN_S );
257 3558 : }
258 :
259 4041 : *out_estimate_present = 1;
260 4041 : return estimate;
261 4470 : }
262 :
263 : /* TODO: This function should be called from genesis bootup as well with
264 : parent_epoch = NULL
265 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2158-L2215 */
266 : void
267 : fd_sysvar_clock_update( fd_bank_t * bank,
268 : fd_accdb_t * accdb,
269 : fd_capture_ctx_t * capture_ctx,
270 : fd_runtime_stack_t * runtime_stack,
271 4470 : ulong const * parent_epoch ) {
272 4470 : fd_sol_sysvar_clock_t clock_[1];
273 4470 : fd_sol_sysvar_clock_t * clock = fd_sysvar_clock_read( accdb, bank->accdb_fork_id, clock_ );
274 4470 : if( FD_UNLIKELY( !clock ) ) FD_LOG_ERR(( "fd_sysvar_clock_read failed" ));
275 :
276 4470 : fd_epoch_schedule_t const * epoch_schedule = &bank->f.epoch_schedule;
277 4470 : ulong current_slot = bank->f.slot;
278 4470 : ulong current_epoch = fd_slot_to_epoch( epoch_schedule, current_slot, NULL );
279 :
280 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2159 */
281 4470 : long unix_timestamp = clock->unix_timestamp;
282 :
283 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2175 */
284 4470 : long ancestor_timestamp = clock->unix_timestamp;
285 :
286 : /* TODO: Are we handling slot 0 correctly?
287 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2176-L2183 */
288 4470 : int estimate_present = 0;
289 4470 : long timestamp_estimate = get_timestamp_estimate( bank, clock, runtime_stack, parent_epoch, &estimate_present );
290 :
291 : /* If the timestamp was successfully calculated, use it. Otherwise,
292 : keep the old one. */
293 4470 : if( FD_LIKELY( estimate_present ) ) {
294 4041 : unix_timestamp = timestamp_estimate;
295 :
296 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2180-L2182 */
297 4041 : if( timestamp_estimate<ancestor_timestamp ) {
298 3 : unix_timestamp = ancestor_timestamp;
299 3 : }
300 4041 : }
301 :
302 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2191-L2197 */
303 4470 : long epoch_start_timestamp = (parent_epoch!=NULL && *parent_epoch!=current_epoch) ?
304 270 : unix_timestamp :
305 4470 : clock->epoch_start_timestamp;
306 :
307 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2198-L2201 */
308 4470 : if( FD_UNLIKELY( current_slot==0UL ) ) {
309 0 : long timestamp_from_genesis = unix_timestamp_from_genesis( bank );
310 0 : unix_timestamp = timestamp_from_genesis;
311 0 : epoch_start_timestamp = timestamp_from_genesis;
312 0 : }
313 :
314 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2202-L2208 */
315 4470 : *clock = (fd_sol_sysvar_clock_t){
316 4470 : .slot = current_slot,
317 4470 : .epoch_start_timestamp = epoch_start_timestamp,
318 4470 : .epoch = current_epoch,
319 4470 : .leader_schedule_epoch = fd_slot_to_leader_schedule_epoch( epoch_schedule, current_slot ),
320 4470 : .unix_timestamp = unix_timestamp,
321 4470 : };
322 :
323 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2209-L2214 */
324 4470 : fd_sysvar_clock_write( bank, accdb, capture_ctx, clock );
325 4470 : }
|
