Line data Source code
1 : #include "fd_sysvar.h"
2 : #include "fd_sysvar_clock.h"
3 : #include "fd_sysvar_epoch_schedule.h"
4 : #include "../fd_acc_mgr.h"
5 : #include "../fd_system_ids.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 0 : #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 0 : #define MAX_ALLOWABLE_DRIFT_SLOW_PERCENT ( 150U )
42 :
43 : /* Do all intermediate calculations at nanosecond precision, to mirror
44 : Solana's behavior. */
45 0 : #define NS_IN_S ((long)1e9)
46 :
47 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamps.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)fd_bank_genesis_creation_time_get( bank ),
53 0 : (long)( fd_uint128_sat_mul( fd_bank_slot_get( bank ), fd_bank_ns_per_slot_get( bank ) ) / NS_IN_S ) );
54 0 : }
55 :
56 : void
57 : fd_sysvar_clock_write( fd_bank_t * bank,
58 : fd_funk_t * funk,
59 : fd_funk_txn_xid_t const * xid,
60 : fd_capture_ctx_t * capture_ctx,
61 0 : fd_sol_sysvar_clock_t * clock ) {
62 0 : uchar enc[ sizeof(fd_sol_sysvar_clock_t) ];
63 0 : fd_bincode_encode_ctx_t ctx = {
64 0 : .data = enc,
65 0 : .dataend = enc + sizeof(fd_sol_sysvar_clock_t),
66 0 : };
67 0 : if( FD_UNLIKELY( fd_sol_sysvar_clock_encode( clock, &ctx ) ) ) {
68 0 : FD_LOG_ERR(( "fd_sol_sysvar_clock_encode failed" ));
69 0 : }
70 :
71 0 : fd_sysvar_account_update( bank, funk, xid, capture_ctx, &fd_sysvar_clock_id, enc, sizeof(fd_sol_sysvar_clock_t) );
72 0 : }
73 :
74 :
75 : fd_sol_sysvar_clock_t *
76 : fd_sysvar_clock_read( fd_funk_t * funk,
77 : fd_funk_txn_xid_t const * xid,
78 0 : fd_sol_sysvar_clock_t * clock ) {
79 0 : fd_txn_account_t acc[1];
80 0 : int rc = fd_txn_account_init_from_funk_readonly( acc, &fd_sysvar_clock_id, funk, xid );
81 0 : if( FD_UNLIKELY( rc!=FD_ACC_MGR_SUCCESS ) ) {
82 0 : return NULL;
83 0 : }
84 :
85 : /* This check is needed as a quirk of the fuzzer. If a sysvar account
86 : exists in the accounts database, but doesn't have any lamports,
87 : this means that the account does not exist. This wouldn't happen
88 : in a real execution environment. */
89 0 : if( FD_UNLIKELY( fd_txn_account_get_lamports( acc )==0UL ) ) {
90 0 : return NULL;
91 0 : }
92 :
93 0 : return fd_bincode_decode_static(
94 0 : sol_sysvar_clock, clock,
95 0 : fd_txn_account_get_data( acc ),
96 0 : fd_txn_account_get_data_len( acc ),
97 0 : &err );
98 0 : }
99 :
100 : void
101 : fd_sysvar_clock_init( fd_bank_t * bank,
102 : fd_funk_t * funk,
103 : fd_funk_txn_xid_t const * xid,
104 0 : fd_capture_ctx_t * capture_ctx ) {
105 0 : long timestamp = unix_timestamp_from_genesis( bank );
106 :
107 0 : fd_sol_sysvar_clock_t clock = {
108 0 : .slot = fd_bank_slot_get( bank ),
109 0 : .epoch = 0,
110 0 : .epoch_start_timestamp = timestamp,
111 0 : .leader_schedule_epoch = 1,
112 0 : .unix_timestamp = timestamp,
113 0 : };
114 0 : fd_sysvar_clock_write( bank, funk, xid, capture_ctx, &clock );
115 0 : }
116 :
117 : struct ts_est_ele {
118 : long timestamp;
119 : uint128 stake; /* should really be fine as ulong, but we match Agave*/
120 : };
121 :
122 : typedef struct ts_est_ele ts_est_ele_t;
123 :
124 : #define SORT_NAME sort_stake_ts
125 0 : #define SORT_KEY_T ts_est_ele_t
126 0 : #define SORT_BEFORE(a,b) ( (a).timestamp < (b).timestamp )
127 : #include "../../../util/tmpl/fd_sort.c"
128 :
129 : /* get_timestamp_estimate calculates a timestamp estimate. Does not
130 : modify the slot context. Walks all cached vote accounts (from the
131 : "bank") and calculates a unix timestamp estimate. Returns the
132 : timestamp estimate. spad is used for scratch allocations (allocates
133 : a treap of size FD_SYSVAR_CLOCK_STAKE_WEIGHTS_MAX). Crashes the
134 : process with FD_LOG_ERR on failure (e.g. too many vote accounts).
135 :
136 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2563-L2601 */
137 : long
138 : get_timestamp_estimate( fd_bank_t * bank,
139 0 : fd_sol_sysvar_clock_t * clock ) {
140 0 : fd_epoch_schedule_t const * epoch_schedule = fd_bank_epoch_schedule_query( bank );
141 0 : ulong slot_duration = (ulong)fd_bank_ns_per_slot_get( bank );
142 0 : ulong current_slot = fd_bank_slot_get( bank );
143 :
144 0 : static FD_TL ts_est_ele_t ts_eles[ FD_RUNTIME_MAX_VOTE_ACCOUNTS ];
145 0 : ulong ts_ele_cnt = 0UL;
146 :
147 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L41 */
148 0 : uint128 total_stake = 0UL;
149 :
150 : /* A timestamp estimate is calculated at every slot using the most
151 : recent vote states of voting validators. This estimated is based on
152 : a stake weighted median using the stake as of the end of epoch E-2
153 : if we are currently in epoch E. We do not count vote accounts that
154 : have not voted in an epoch's worth of slots (432k). */
155 0 : fd_vote_states_t const * vote_states = fd_bank_vote_states_locking_query( bank );
156 0 : fd_vote_states_t const * vote_states_prev_prev = fd_bank_vote_states_prev_prev_locking_query( bank );
157 :
158 0 : FD_TEST( fd_vote_states_cnt( vote_states )<=FD_RUNTIME_MAX_VOTE_ACCOUNTS );
159 :
160 0 : fd_vote_states_iter_t iter_[1];
161 0 : for( fd_vote_states_iter_t * iter = fd_vote_states_iter_init( iter_, vote_states );
162 0 : !fd_vote_states_iter_done( iter );
163 0 : fd_vote_states_iter_next( iter ) ) {
164 0 : fd_vote_state_ele_t const * vote_state = fd_vote_states_iter_ele( iter );
165 :
166 : /* https://github.com/anza-xyz/agave/blob/v3.0.0/runtime/src/bank.rs#L2445 */
167 0 : ulong slot_delta;
168 0 : int err = fd_ulong_checked_sub( current_slot, vote_state->last_vote_slot, &slot_delta );
169 0 : if( FD_UNLIKELY( err ) ) {
170 : /* Don't count vote accounts with a last vote slot that is greater
171 : than the current slot. */
172 0 : continue;
173 0 : }
174 :
175 : /* TODO: This should be pre-cached so we don't do map lookup here */
176 0 : fd_vote_state_ele_t const * vote_state_prev = fd_vote_states_query_const( vote_states_prev_prev, &vote_state->vote_account );
177 0 : if( FD_UNLIKELY( !vote_state_prev ) ) {
178 : /* Don't count vote accounts that didn't have stake at the end of
179 : epoch E-2. */
180 0 : continue;
181 0 : }
182 :
183 : /* Don't count vote accounts that haven't voted in the past 432k
184 : slots (length of an epoch).
185 : https://github.com/anza-xyz/agave/blob/v3.0.0/runtime/src/bank.rs#L2446-L2447 */
186 0 : if( FD_UNLIKELY( slot_delta>epoch_schedule->slots_per_epoch ) ) {
187 0 : continue;
188 0 : }
189 :
190 : /* Calculate the timestamp estimate by taking the last vote
191 : timestamp and adding the estimated time since the last vote
192 : (delta from last vote slot to current slot * slot duration).
193 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L44-L45 */
194 0 : ulong offset = fd_ulong_sat_mul( slot_duration, slot_delta );
195 0 : long estimate = vote_state->last_vote_timestamp + (long)(offset / NS_IN_S);
196 :
197 : /* For each timestamp, accumulate the stake from E-2. If the entry
198 : for the timestamp doesn't exist yet, insert it. Otherwise,
199 : update the existing entry.
200 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L46-L53 */
201 0 : ts_eles[ ts_ele_cnt ] = (ts_est_ele_t){
202 0 : .timestamp = estimate,
203 0 : .stake = vote_state_prev->stake,
204 0 : };
205 0 : ts_ele_cnt++;
206 :
207 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L54 */
208 0 : total_stake += vote_state_prev->stake;
209 0 : }
210 0 : fd_bank_vote_states_end_locking_query( bank );
211 0 : fd_bank_vote_states_prev_prev_end_locking_query( bank );
212 :
213 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L56-L58 */
214 0 : if( FD_UNLIKELY( total_stake==0UL ) ) {
215 0 : return 0L;
216 0 : }
217 :
218 0 : sort_stake_ts_inplace( ts_eles, ts_ele_cnt );
219 :
220 : /* Populate estimate with the stake-weighted median timestamp.
221 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L59-L68 */
222 0 : uint128 stake_accumulator = 0;
223 0 : long estimate = 0L;
224 0 : for( ulong i=0UL; i<ts_ele_cnt; i++ ) {
225 0 : stake_accumulator = fd_uint128_sat_add( stake_accumulator, ts_eles[i].stake );
226 0 : if( stake_accumulator>(total_stake/2UL) ) {
227 0 : estimate = ts_eles[ i ].timestamp;
228 0 : break;
229 0 : }
230 0 : }
231 :
232 0 : int const fix_estimate_into_u64 = FD_FEATURE_ACTIVE_BANK( bank, warp_timestamp_again );
233 :
234 : /* Bound estimate by `max_allowable_drift` since the start of the epoch
235 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L69-L99 */
236 0 : ulong epoch_start_slot = fd_epoch_slot0( epoch_schedule, clock->epoch );
237 0 : long epoch_start_timestamp = clock->epoch_start_timestamp;
238 :
239 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L71-L72 */
240 0 : ulong poh_estimate_offset = fd_ulong_sat_mul( slot_duration, fd_ulong_sat_sub( current_slot, epoch_start_slot ) );
241 :
242 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L73-L77 */
243 0 : ulong estimate_offset;
244 0 : if( fix_estimate_into_u64 ) {
245 0 : estimate_offset = fd_ulong_sat_mul( NS_IN_S, fd_ulong_sat_sub( (ulong)estimate, (ulong)epoch_start_timestamp ) );
246 0 : } else {
247 0 : estimate_offset = fd_ulong_sat_mul( NS_IN_S, (ulong)fd_long_sat_sub( estimate, epoch_start_timestamp ) );
248 0 : }
249 :
250 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L78-L81 */
251 0 : ulong max_allowable_drift_fast = fd_ulong_sat_mul( poh_estimate_offset, MAX_ALLOWABLE_DRIFT_FAST_PERCENT ) / 100UL;
252 0 : ulong max_allowable_drift_slow = fd_ulong_sat_mul( poh_estimate_offset, MAX_ALLOWABLE_DRIFT_SLOW_PERCENT ) / 100UL;
253 :
254 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L82-L98 */
255 0 : if( estimate_offset>poh_estimate_offset && fd_ulong_sat_sub( estimate_offset, poh_estimate_offset )>max_allowable_drift_slow ) {
256 0 : estimate = fd_long_sat_add(
257 0 : epoch_start_timestamp,
258 0 : fd_long_sat_add( (long)poh_estimate_offset / NS_IN_S, (long)max_allowable_drift_slow / NS_IN_S ) );
259 0 : } else if( estimate_offset<poh_estimate_offset && fd_ulong_sat_sub( poh_estimate_offset, estimate_offset )>max_allowable_drift_fast ) {
260 0 : estimate = fd_long_sat_sub(
261 0 : fd_long_sat_add( epoch_start_timestamp, (long)poh_estimate_offset / NS_IN_S ),
262 0 : (long)max_allowable_drift_fast / NS_IN_S );
263 0 : }
264 :
265 0 : return estimate;
266 0 : }
267 :
268 : /* TODO: This function should be called from genesis bootup as well with
269 : parent_epoch = NULL
270 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2158-L2215 */
271 : void
272 : fd_sysvar_clock_update( fd_bank_t * bank,
273 : fd_funk_t * funk,
274 : fd_funk_txn_xid_t const * xid,
275 : fd_capture_ctx_t * capture_ctx,
276 0 : ulong const * parent_epoch ) {
277 0 : fd_sol_sysvar_clock_t clock_[1];
278 0 : fd_sol_sysvar_clock_t * clock = fd_sysvar_clock_read( funk, xid, clock_ );
279 0 : if( FD_UNLIKELY( !clock ) ) FD_LOG_ERR(( "fd_sysvar_clock_read failed" ));
280 :
281 0 : fd_epoch_schedule_t const * epoch_schedule = fd_bank_epoch_schedule_query( bank );
282 0 : ulong current_slot = fd_bank_slot_get( bank );
283 0 : ulong current_epoch = fd_slot_to_epoch( epoch_schedule, current_slot, NULL );
284 :
285 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2159 */
286 0 : long unix_timestamp = clock->unix_timestamp;
287 :
288 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2175 */
289 0 : long ancestor_timestamp = clock->unix_timestamp;
290 :
291 : /* TODO: Are we handling slot 0 correctly?
292 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2176-L2183 */
293 0 : long timestamp_estimate = get_timestamp_estimate( bank, clock );
294 :
295 : /* If the timestamp was successfully calculated, use it. It not keep the old one. */
296 0 : if( FD_LIKELY( timestamp_estimate!=0L ) ) {
297 0 : unix_timestamp = timestamp_estimate;
298 :
299 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2180-L2182 */
300 0 : if( timestamp_estimate<ancestor_timestamp ) {
301 0 : unix_timestamp = ancestor_timestamp;
302 0 : }
303 0 : }
304 :
305 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2191-L2197 */
306 0 : long epoch_start_timestamp = (parent_epoch!=NULL && *parent_epoch!=current_epoch) ?
307 0 : unix_timestamp :
308 0 : clock->epoch_start_timestamp;
309 :
310 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2198-L2201 */
311 0 : if( FD_UNLIKELY( current_slot==0UL ) ) {
312 0 : long timestamp_from_genesis = unix_timestamp_from_genesis( bank );
313 0 : unix_timestamp = timestamp_from_genesis;
314 0 : epoch_start_timestamp = timestamp_from_genesis;
315 0 : }
316 :
317 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2202-L2208 */
318 0 : *clock = (fd_sol_sysvar_clock_t){
319 0 : .slot = current_slot,
320 0 : .epoch_start_timestamp = epoch_start_timestamp,
321 0 : .epoch = current_epoch,
322 0 : .leader_schedule_epoch = fd_slot_to_leader_schedule_epoch( epoch_schedule, current_slot ),
323 0 : .unix_timestamp = unix_timestamp,
324 0 : };
325 :
326 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2209-L2214 */
327 0 : fd_sysvar_clock_write( bank, funk, xid, capture_ctx, clock );
328 0 : }
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