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 */
38 414 : #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 */
41 414 : #define MAX_ALLOWABLE_DRIFT_SLOW_PERCENT ( 150U )
42 :
43 : /* Do all intermediate calculations at nanosecond precision, to mirror
44 : Solana's behavior. */
45 1134 : #define NS_IN_S ((long)1e9)
46 :
47 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2110-L2117 */
48 : static inline long
49 0 : unix_timestamp_from_genesis( fd_bank_t * bank ) {
50 : /* TODO: genesis_creation_time needs to be a long in the bank. */
51 0 : return fd_long_sat_add(
52 0 : (long)bank->f.genesis_creation_time,
53 0 : (long)( fd_uint128_sat_mul( bank->f.slot, bank->f.slot_params.ns_per_slot ) / NS_IN_S ) );
54 0 : }
55 :
56 : static void
57 : fd_sysvar_clock_write( fd_bank_t * bank,
58 : fd_accdb_t * accdb,
59 : fd_capture_ctx_t * capture_ctx,
60 615 : fd_sol_sysvar_clock_t const * clock ) {
61 615 : fd_sysvar_account_update( bank, accdb, capture_ctx, &fd_sysvar_clock_id, clock, sizeof(fd_sol_sysvar_clock_t) );
62 615 : }
63 :
64 : fd_sol_sysvar_clock_t *
65 : fd_sysvar_clock_read( fd_accdb_t * accdb,
66 : fd_accdb_fork_id_t fork_id,
67 614 : fd_sol_sysvar_clock_t * clock ) {
68 614 : fd_acc_t acc = fd_accdb_read_one( accdb, fork_id, fd_sysvar_clock_id.uc );
69 614 : if( FD_UNLIKELY( !acc.lamports || acc.data_len<sizeof(fd_sol_sysvar_clock_t) ) ) {
70 : /* This check is needed as a quirk of the fuzzer. If a sysvar
71 : account exists in the accounts database, but doesn't have any
72 : lamports, this means that the account does not exist. This
73 : wouldn't happen in a real execution environment. */
74 0 : fd_accdb_unread_one( accdb, &acc );
75 0 : return NULL;
76 0 : }
77 :
78 614 : fd_memcpy( clock, acc.data, sizeof(fd_sol_sysvar_clock_t) );
79 614 : fd_accdb_unread_one( accdb, &acc );
80 614 : return clock;
81 614 : }
82 :
83 : void
84 : fd_sysvar_clock_init( fd_bank_t * bank,
85 : fd_accdb_t * accdb,
86 0 : fd_capture_ctx_t * capture_ctx ) {
87 0 : long timestamp = unix_timestamp_from_genesis( bank );
88 :
89 0 : fd_sol_sysvar_clock_t clock = {
90 0 : .slot = bank->f.slot,
91 0 : .epoch = 0,
92 0 : .epoch_start_timestamp = timestamp,
93 0 : .leader_schedule_epoch = 1,
94 0 : .unix_timestamp = timestamp,
95 0 : };
96 0 : fd_sysvar_clock_write( bank, accdb, capture_ctx, &clock );
97 0 : }
98 :
99 : #define SORT_NAME sort_stake_ts
100 121 : #define SORT_KEY_T ts_est_ele_t
101 69 : #define SORT_BEFORE(a,b) ( (a).timestamp < (b).timestamp )
102 : #include "../../../util/tmpl/fd_sort.c"
103 :
104 : static void
105 : accum_vote_stakes( fd_bank_t * bank,
106 : fd_runtime_stack_t * runtime_stack,
107 : uint128 * total_stake_out,
108 614 : ulong * ts_ele_cnt_out ) {
109 :
110 614 : ts_est_ele_t * ts_eles = runtime_stack->clock_ts.staked_ts;
111 614 : ulong ts_ele_cnt = 0UL;
112 :
113 614 : uint128 total_stake = 0UL;
114 :
115 614 : fd_epoch_schedule_t const * epoch_schedule = &bank->f.epoch_schedule;
116 614 : ulong current_slot = bank->f.slot;
117 :
118 614 : fd_vote_stakes_t * vote_stakes = fd_bank_vote_stakes( bank );
119 614 : ulong fork_id = bank->vote_stakes_fork_id;
120 :
121 614 : ulong stake [ FD_RUNTIME_MAX_VAT_VOTE_ACCOUNTS ];
122 614 : ulong last_vote_slots[ FD_RUNTIME_MAX_VAT_VOTE_ACCOUNTS ];
123 614 : long last_vote_tss [ FD_RUNTIME_MAX_VAT_VOTE_ACCOUNTS ];
124 614 : ulong vote_cnt = fd_vote_stakes_t_2_votes( vote_stakes, fork_id, stake, last_vote_slots, last_vote_tss );
125 1658 : for( ulong i=0UL; i<vote_cnt; i++ ) {
126 1044 : ulong last_vote_slot = last_vote_slots[ i ];
127 1044 : long last_vote_timestamp = last_vote_tss[ i ];
128 :
129 : /* https://github.com/anza-xyz/agave/blob/v3.0.0/runtime/src/bank.rs#L2445 */
130 1044 : if( FD_UNLIKELY( current_slot<last_vote_slot ) ) {
131 : /* Don't count vote accounts with a last vote slot that is greater
132 : than the current slot. */
133 503 : continue;
134 503 : }
135 541 : ulong slot_delta = current_slot-last_vote_slot;
136 :
137 : /* Don't count vote accounts that haven't voted in the past 432k
138 : slots (length of an epoch).
139 : https://github.com/anza-xyz/agave/blob/v3.0.0/runtime/src/bank.rs#L2446-L2447 */
140 541 : if( FD_UNLIKELY( slot_delta>epoch_schedule->slots_per_epoch ) ) {
141 75 : continue;
142 75 : }
143 :
144 : /* Calculate the timestamp estimate by taking the last vote
145 : timestamp and adding the estimated time since the last vote
146 : (delta from last vote slot to current slot * slot duration).
147 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L44-L45 */
148 466 : ulong offset = fd_slot_params_slot_range_duration_ns( bank, last_vote_slot+1UL, current_slot+1UL );
149 466 : long estimate = fd_long_sat_add( last_vote_timestamp, (long)(offset / NS_IN_S) );
150 :
151 : /* For each timestamp, accumulate the stake from E-2. If the entry
152 : for the timestamp doesn't exist yet, insert it. Otherwise,
153 : update the existing entry.
154 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L46-L53 */
155 466 : ts_eles[ ts_ele_cnt ] = (ts_est_ele_t){
156 466 : .timestamp = estimate,
157 466 : .stake = { .ud=stake[ i ] },
158 466 : };
159 466 : ts_ele_cnt++;
160 :
161 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L54 */
162 466 : total_stake += stake[ i ];
163 466 : }
164 :
165 614 : *total_stake_out = total_stake;
166 614 : *ts_ele_cnt_out = ts_ele_cnt;
167 614 : }
168 :
169 : /* get_timestamp_estimate calculates a timestamp estimate. Does not
170 : modify the slot context. Walks all cached vote accounts (from the
171 : "bank") and calculates a unix timestamp estimate. Returns the
172 : timestamp estimate. Crashes the process with FD_LOG_ERR on failure
173 : (e.g. too many vote accounts).
174 :
175 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2563-L2601 */
176 : static long
177 : get_timestamp_estimate( fd_bank_t * bank,
178 : fd_sol_sysvar_clock_t * clock,
179 : fd_runtime_stack_t * runtime_stack,
180 : ulong const * parent_epoch,
181 614 : int * out_estimate_present ) {
182 614 : fd_epoch_schedule_t const * epoch_schedule = &bank->f.epoch_schedule;
183 614 : ulong current_slot = bank->f.slot;
184 :
185 614 : ts_est_ele_t * ts_eles = runtime_stack->clock_ts.staked_ts;
186 :
187 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L41 */
188 614 : ulong ts_ele_cnt = 0UL;
189 614 : uint128 total_stake = 0UL;
190 :
191 : /* A timestamp estimate is calculated at every slot using the most
192 : recent vote states of voting validators. This estimated is based on
193 : a stake weighted median using the stake as of the end of epoch E-2
194 : if we are currently in epoch E. We do not count vote accounts that
195 : have not voted in an epoch's worth of slots (432k). */
196 :
197 614 : ulong curr_epoch = fd_slot_to_epoch( epoch_schedule, bank->f.slot, NULL );
198 :
199 614 : accum_vote_stakes( bank, runtime_stack, &total_stake, &ts_ele_cnt );
200 :
201 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L56-L58 */
202 614 : if( FD_UNLIKELY( total_stake==0UL ) ) {
203 200 : *out_estimate_present = 0;
204 200 : return 0L;
205 200 : }
206 :
207 414 : sort_stake_ts_inplace( ts_eles, ts_ele_cnt );
208 :
209 : /* Populate estimate with the stake-weighted median timestamp.
210 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L59-L68 */
211 414 : uint128 stake_accumulator = 0;
212 414 : long estimate = 0L;
213 435 : for( ulong i=0UL; i<ts_ele_cnt; i++ ) {
214 435 : stake_accumulator = fd_uint128_sat_add( stake_accumulator, ts_eles[i].stake.ud );
215 435 : if( stake_accumulator>(total_stake/2UL) ) {
216 415 : estimate = ts_eles[ i ].timestamp;
217 415 : break;
218 415 : }
219 435 : }
220 :
221 : /* Bound estimate by `max_allowable_drift` since the start of the
222 : epoch.
223 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L69-L99 */
224 >1844*10^16 : ulong epoch_for_start_slot = parent_epoch ? *parent_epoch : curr_epoch;
225 414 : ulong epoch_start_slot = fd_epoch_slot0( epoch_schedule, epoch_for_start_slot );
226 414 : long epoch_start_timestamp = clock->epoch_start_timestamp;
227 :
228 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L71-L72 */
229 414 : ulong poh_estimate_offset = fd_slot_params_slot_range_duration_ns( bank, epoch_start_slot+1UL, current_slot+1UL );
230 :
231 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L73-L77 */
232 414 : ulong estimate_offset = fd_ulong_sat_mul( NS_IN_S, fd_ulong_sat_sub( (ulong)estimate, (ulong)epoch_start_timestamp ) );
233 :
234 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L78-L81 */
235 414 : ulong max_allowable_drift_fast = fd_ulong_sat_mul( poh_estimate_offset, MAX_ALLOWABLE_DRIFT_FAST_PERCENT ) / 100UL;
236 414 : ulong max_allowable_drift_slow = fd_ulong_sat_mul( poh_estimate_offset, MAX_ALLOWABLE_DRIFT_SLOW_PERCENT ) / 100UL;
237 :
238 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L82-L98 */
239 414 : if( estimate_offset>poh_estimate_offset && fd_ulong_sat_sub( estimate_offset, poh_estimate_offset )>max_allowable_drift_slow ) {
240 92 : estimate = fd_long_sat_add(
241 92 : epoch_start_timestamp,
242 92 : fd_long_sat_add( (long)poh_estimate_offset / NS_IN_S, (long)max_allowable_drift_slow / NS_IN_S ) );
243 322 : } else if( estimate_offset<poh_estimate_offset && fd_ulong_sat_sub( poh_estimate_offset, estimate_offset )>max_allowable_drift_fast ) {
244 35 : estimate = fd_long_sat_sub(
245 35 : fd_long_sat_add( epoch_start_timestamp, (long)poh_estimate_offset / NS_IN_S ),
246 35 : (long)max_allowable_drift_fast / NS_IN_S );
247 35 : }
248 :
249 414 : *out_estimate_present = 1;
250 414 : return estimate;
251 614 : }
252 :
253 : /* TODO: This function should be called from genesis bootup as well with
254 : parent_epoch = NULL
255 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2158-L2215 */
256 : void
257 : fd_sysvar_clock_update( fd_bank_t * bank,
258 : fd_accdb_t * accdb,
259 : fd_capture_ctx_t * capture_ctx,
260 : fd_runtime_stack_t * runtime_stack,
261 614 : ulong const * parent_epoch ) {
262 614 : fd_sol_sysvar_clock_t clock_[1];
263 614 : fd_sol_sysvar_clock_t * clock = fd_sysvar_clock_read( accdb, bank->accdb_fork_id, clock_ );
264 614 : if( FD_UNLIKELY( !clock ) ) FD_LOG_ERR(( "fd_sysvar_clock_read failed" ));
265 :
266 614 : fd_epoch_schedule_t const * epoch_schedule = &bank->f.epoch_schedule;
267 614 : ulong current_slot = bank->f.slot;
268 614 : ulong current_epoch = fd_slot_to_epoch( epoch_schedule, current_slot, NULL );
269 :
270 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2159 */
271 614 : long unix_timestamp = clock->unix_timestamp;
272 :
273 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2175 */
274 614 : long ancestor_timestamp = clock->unix_timestamp;
275 :
276 : /* TODO: Are we handling slot 0 correctly?
277 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2176-L2183 */
278 614 : int estimate_present = 0;
279 614 : long timestamp_estimate = get_timestamp_estimate( bank, clock, runtime_stack, parent_epoch, &estimate_present );
280 :
281 : /* If the timestamp was successfully calculated, use it. Otherwise,
282 : keep the old one. */
283 614 : if( FD_LIKELY( estimate_present ) ) {
284 415 : unix_timestamp = timestamp_estimate;
285 :
286 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2180-L2182 */
287 415 : if( timestamp_estimate<ancestor_timestamp ) {
288 13 : unix_timestamp = ancestor_timestamp;
289 13 : }
290 415 : }
291 :
292 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2191-L2197 */
293 615 : long epoch_start_timestamp = (parent_epoch!=NULL && *parent_epoch!=current_epoch) ?
294 32 : unix_timestamp :
295 614 : clock->epoch_start_timestamp;
296 :
297 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2198-L2201 */
298 614 : if( FD_UNLIKELY( current_slot==0UL ) ) {
299 0 : long timestamp_from_genesis = unix_timestamp_from_genesis( bank );
300 0 : unix_timestamp = timestamp_from_genesis;
301 0 : epoch_start_timestamp = timestamp_from_genesis;
302 0 : }
303 :
304 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2202-L2208 */
305 614 : *clock = (fd_sol_sysvar_clock_t){
306 614 : .slot = current_slot,
307 614 : .epoch_start_timestamp = epoch_start_timestamp,
308 614 : .epoch = current_epoch,
309 614 : .leader_schedule_epoch = fd_slot_to_leader_schedule_epoch( epoch_schedule, current_slot ),
310 614 : .unix_timestamp = unix_timestamp,
311 614 : };
312 :
313 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2209-L2214 */
314 614 : fd_sysvar_clock_write( bank, accdb, capture_ctx, clock );
315 614 : }
316 :
317 : void
318 : fd_sysvar_clock_update_slot_alpenglow( fd_bank_t * bank,
319 : fd_accdb_t * accdb,
320 0 : fd_capture_ctx_t * capture_ctx ) {
321 0 : fd_sol_sysvar_clock_t clock_[1];
322 0 : fd_sol_sysvar_clock_t * clock = fd_sysvar_clock_read( accdb, bank->accdb_fork_id, clock_ );
323 0 : if( FD_UNLIKELY( !clock ) ) FD_LOG_ERR(( "fd_sysvar_clock_read failed" ));
324 :
325 0 : fd_epoch_schedule_t const * epoch_schedule = &bank->f.epoch_schedule;
326 0 : ulong current_epoch = fd_slot_to_epoch( epoch_schedule, bank->f.slot, NULL );
327 0 : ulong parent_epoch = fd_slot_to_epoch( epoch_schedule, bank->f.parent_slot, NULL );
328 :
329 0 : long epoch_start_timestamp;
330 0 : if( FD_UNLIKELY( !bank->f.slot ) ) epoch_start_timestamp = unix_timestamp_from_genesis( bank );
331 0 : else if( FD_UNLIKELY( parent_epoch!=current_epoch ) ) epoch_start_timestamp = clock->unix_timestamp;
332 0 : else epoch_start_timestamp = clock->epoch_start_timestamp;
333 :
334 0 : *clock = (fd_sol_sysvar_clock_t){
335 0 : .slot = bank->f.slot,
336 0 : .epoch_start_timestamp = epoch_start_timestamp,
337 0 : .epoch = current_epoch,
338 0 : .leader_schedule_epoch = fd_slot_to_leader_schedule_epoch( epoch_schedule, bank->f.slot ),
339 0 : .unix_timestamp = clock->unix_timestamp, /* parent's footer timestamp */
340 0 : };
341 0 : fd_sysvar_clock_write( bank, accdb, capture_ctx, clock );
342 0 : }
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