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_runtime_stack.h"
5 : #include "../fd_acc_mgr.h"
6 : #include "../fd_system_ids.h"
7 : #include "../program/fd_program_util.h"
8 :
9 : /* Syvar Clock Possible Values:
10 : slot:
11 : [0, ULONG_MAX]
12 :
13 : epoch:
14 : [0, slot/432000UL]
15 :
16 : epoch_start_timestamp:
17 : [0, ULONG_MAX]
18 :
19 : unix_timestamp:
20 : This value is bounded by the slot distance from the
21 : epoch_start_timestamp.
22 : The protocol allows for a maximum drift (either fast or slow) from the
23 : start of the epoch's timestamp. The expected time is called the PoH
24 : offset. This offset is calculated by (epoch_start_timestamp + slots
25 : since epoch * slot_duration). The drift is then bounded by the
26 : max_allowable_drift_{slow,fast}. The stake weighted offset can be
27 : 150% more than the PoH offset and 25% less than the PoH offset.
28 : So, the bounds for the unix_timestamp can be calculated by:
29 : upper bound = epoch_start_timestamp + (slots since epoch * slot_duration) * 2.5
30 : lower bound = epoch_start_timestamp + (slots since epoch * slot_duration) * 0.75
31 :
32 : leader_schedule_epoch:
33 : This is the value of the epoch used for the leader schedule. It is
34 : computed based on the values of the epoch schedule (first_normal_slot,
35 : leader_schedule_slot_offset, slots_per_epoch). It is always equal to
36 : ((slot - first_normal_slot) + leader_schedule_slot_offset) / schedule->slots_per_epoch
37 : */
38 :
39 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L14 */
40 0 : #define MAX_ALLOWABLE_DRIFT_FAST_PERCENT ( 25U )
41 :
42 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L15 */
43 0 : #define MAX_ALLOWABLE_DRIFT_SLOW_PERCENT ( 150U )
44 :
45 : /* Do all intermediate calculations at nanosecond precision, to mirror
46 : Solana's behavior. */
47 0 : #define NS_IN_S ((long)1e9)
48 :
49 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamps.rs#L2110-L2117 */
50 : static inline long
51 0 : unix_timestamp_from_genesis( fd_bank_t * bank ) {
52 : /* TODO: genesis_creation_time needs to be a long in the bank. */
53 0 : return fd_long_sat_add(
54 0 : (long)fd_bank_genesis_creation_time_get( bank ),
55 0 : (long)( fd_uint128_sat_mul( fd_bank_slot_get( bank ), fd_bank_ns_per_slot_get( bank ) ) / NS_IN_S ) );
56 0 : }
57 :
58 : void
59 : fd_sysvar_clock_write( fd_bank_t * bank,
60 : fd_accdb_user_t * accdb,
61 : fd_funk_txn_xid_t const * xid,
62 : fd_capture_ctx_t * capture_ctx,
63 0 : fd_sol_sysvar_clock_t * clock ) {
64 0 : uchar enc[ sizeof(fd_sol_sysvar_clock_t) ];
65 0 : fd_bincode_encode_ctx_t ctx = {
66 0 : .data = enc,
67 0 : .dataend = enc + sizeof(fd_sol_sysvar_clock_t),
68 0 : };
69 0 : if( FD_UNLIKELY( fd_sol_sysvar_clock_encode( clock, &ctx ) ) ) {
70 0 : FD_LOG_ERR(( "fd_sol_sysvar_clock_encode failed" ));
71 0 : }
72 :
73 0 : fd_sysvar_account_update( bank, accdb, xid, capture_ctx, &fd_sysvar_clock_id, enc, sizeof(fd_sol_sysvar_clock_t) );
74 0 : }
75 :
76 :
77 : fd_sol_sysvar_clock_t *
78 : fd_sysvar_clock_read( fd_funk_t * funk,
79 : fd_funk_txn_xid_t const * xid,
80 0 : fd_sol_sysvar_clock_t * clock ) {
81 0 : fd_txn_account_t acc[1];
82 0 : int rc = fd_txn_account_init_from_funk_readonly( acc, &fd_sysvar_clock_id, funk, xid );
83 0 : if( FD_UNLIKELY( rc!=FD_ACC_MGR_SUCCESS ) ) {
84 0 : return NULL;
85 0 : }
86 :
87 : /* This check is needed as a quirk of the fuzzer. If a sysvar account
88 : exists in the accounts database, but doesn't have any lamports,
89 : this means that the account does not exist. This wouldn't happen
90 : in a real execution environment. */
91 0 : if( FD_UNLIKELY( fd_txn_account_get_lamports( acc )==0UL ) ) {
92 0 : return NULL;
93 0 : }
94 :
95 0 : return fd_bincode_decode_static(
96 0 : sol_sysvar_clock, clock,
97 0 : fd_txn_account_get_data( acc ),
98 0 : fd_txn_account_get_data_len( acc ),
99 0 : NULL );
100 0 : }
101 :
102 : void
103 : fd_sysvar_clock_init( fd_bank_t * bank,
104 : fd_accdb_user_t * accdb,
105 : fd_funk_txn_xid_t const * xid,
106 0 : fd_capture_ctx_t * capture_ctx ) {
107 0 : long timestamp = unix_timestamp_from_genesis( bank );
108 :
109 0 : fd_sol_sysvar_clock_t clock = {
110 0 : .slot = fd_bank_slot_get( bank ),
111 0 : .epoch = 0,
112 0 : .epoch_start_timestamp = timestamp,
113 0 : .leader_schedule_epoch = 1,
114 0 : .unix_timestamp = timestamp,
115 0 : };
116 0 : fd_sysvar_clock_write( bank, accdb, xid, capture_ctx, &clock );
117 0 : }
118 :
119 : #define SORT_NAME sort_stake_ts
120 0 : #define SORT_KEY_T ts_est_ele_t
121 0 : #define SORT_BEFORE(a,b) ( (a).timestamp < (b).timestamp )
122 : #include "../../../util/tmpl/fd_sort.c"
123 :
124 : /* get_timestamp_estimate calculates a timestamp estimate. Does not
125 : modify the slot context. Walks all cached vote accounts (from the
126 : "bank") and calculates a unix timestamp estimate. Returns the
127 : timestamp estimate. spad is used for scratch allocations (allocates
128 : a treap of size FD_SYSVAR_CLOCK_STAKE_WEIGHTS_MAX). Crashes the
129 : process with FD_LOG_ERR on failure (e.g. too many vote accounts).
130 :
131 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2563-L2601 */
132 : long
133 : get_timestamp_estimate( fd_bank_t * bank,
134 : fd_sol_sysvar_clock_t * clock,
135 0 : fd_runtime_stack_t * runtime_stack ) {
136 0 : fd_epoch_schedule_t const * epoch_schedule = fd_bank_epoch_schedule_query( bank );
137 0 : ulong slot_duration = (ulong)fd_bank_ns_per_slot_get( bank );
138 0 : ulong current_slot = fd_bank_slot_get( bank );
139 :
140 0 : ts_est_ele_t * ts_eles = runtime_stack->clock_ts.staked_ts;
141 0 : ulong ts_ele_cnt = 0UL;
142 :
143 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L41 */
144 0 : uint128 total_stake = 0UL;
145 :
146 : /* A timestamp estimate is calculated at every slot using the most
147 : recent vote states of voting validators. This estimated is based on
148 : a stake weighted median using the stake as of the end of epoch E-2
149 : if we are currently in epoch E. We do not count vote accounts that
150 : have not voted in an epoch's worth of slots (432k). */
151 0 : fd_vote_states_t const * vote_states = fd_bank_vote_states_locking_query( bank );
152 :
153 0 : FD_TEST( fd_vote_states_cnt( vote_states )<=FD_RUNTIME_MAX_VOTE_ACCOUNTS );
154 :
155 0 : fd_vote_states_iter_t iter_[1];
156 0 : for( fd_vote_states_iter_t * iter = fd_vote_states_iter_init( iter_, vote_states );
157 0 : !fd_vote_states_iter_done( iter );
158 0 : fd_vote_states_iter_next( iter ) ) {
159 0 : fd_vote_state_ele_t const * vote_state = fd_vote_states_iter_ele( iter );
160 :
161 : /* https://github.com/anza-xyz/agave/blob/v3.0.0/runtime/src/bank.rs#L2445 */
162 0 : ulong slot_delta;
163 0 : int err = fd_ulong_checked_sub( current_slot, vote_state->last_vote_slot, &slot_delta );
164 0 : if( FD_UNLIKELY( err ) ) {
165 : /* Don't count vote accounts with a last vote slot that is greater
166 : than the current slot. */
167 0 : continue;
168 0 : }
169 :
170 0 : if( FD_UNLIKELY( !vote_state->stake_t_2 ) ) {
171 : /* Don't count vote accounts that didn't have stake at the end of
172 : epoch E-2. */
173 0 : continue;
174 0 : }
175 :
176 : /* Don't count vote accounts that haven't voted in the past 432k
177 : slots (length of an epoch).
178 : https://github.com/anza-xyz/agave/blob/v3.0.0/runtime/src/bank.rs#L2446-L2447 */
179 0 : if( FD_UNLIKELY( slot_delta>epoch_schedule->slots_per_epoch ) ) {
180 0 : continue;
181 0 : }
182 :
183 : /* Calculate the timestamp estimate by taking the last vote
184 : timestamp and adding the estimated time since the last vote
185 : (delta from last vote slot to current slot * slot duration).
186 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L44-L45 */
187 0 : ulong offset = fd_ulong_sat_mul( slot_duration, slot_delta );
188 0 : long estimate = vote_state->last_vote_timestamp + (long)(offset / NS_IN_S);
189 :
190 : /* For each timestamp, accumulate the stake from E-2. If the entry
191 : for the timestamp doesn't exist yet, insert it. Otherwise,
192 : update the existing entry.
193 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L46-L53 */
194 0 : ts_eles[ ts_ele_cnt ] = (ts_est_ele_t){
195 0 : .timestamp = estimate,
196 0 : .stake = vote_state->stake_t_2,
197 0 : };
198 0 : ts_ele_cnt++;
199 :
200 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L54 */
201 0 : total_stake += vote_state->stake_t_2;
202 0 : }
203 0 : fd_bank_vote_states_end_locking_query( bank );
204 :
205 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L56-L58 */
206 0 : if( FD_UNLIKELY( total_stake==0UL ) ) {
207 0 : return 0L;
208 0 : }
209 :
210 0 : sort_stake_ts_inplace( ts_eles, ts_ele_cnt );
211 :
212 : /* Populate estimate with the stake-weighted median timestamp.
213 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L59-L68 */
214 0 : uint128 stake_accumulator = 0;
215 0 : long estimate = 0L;
216 0 : for( ulong i=0UL; i<ts_ele_cnt; i++ ) {
217 0 : stake_accumulator = fd_uint128_sat_add( stake_accumulator, ts_eles[i].stake );
218 0 : if( stake_accumulator>(total_stake/2UL) ) {
219 0 : estimate = ts_eles[ i ].timestamp;
220 0 : break;
221 0 : }
222 0 : }
223 :
224 0 : int const fix_estimate_into_u64 = FD_FEATURE_ACTIVE_BANK( bank, warp_timestamp_again );
225 :
226 : /* Bound estimate by `max_allowable_drift` since the start of the epoch
227 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L69-L99 */
228 0 : ulong epoch_start_slot = fd_epoch_slot0( epoch_schedule, clock->epoch );
229 0 : long epoch_start_timestamp = clock->epoch_start_timestamp;
230 :
231 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L71-L72 */
232 0 : ulong poh_estimate_offset = fd_ulong_sat_mul( slot_duration, fd_ulong_sat_sub( current_slot, epoch_start_slot ) );
233 :
234 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L73-L77 */
235 0 : ulong estimate_offset;
236 0 : if( fix_estimate_into_u64 ) {
237 0 : estimate_offset = fd_ulong_sat_mul( NS_IN_S, fd_ulong_sat_sub( (ulong)estimate, (ulong)epoch_start_timestamp ) );
238 0 : } else {
239 0 : estimate_offset = fd_ulong_sat_mul( NS_IN_S, (ulong)fd_long_sat_sub( estimate, epoch_start_timestamp ) );
240 0 : }
241 :
242 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L78-L81 */
243 0 : ulong max_allowable_drift_fast = fd_ulong_sat_mul( poh_estimate_offset, MAX_ALLOWABLE_DRIFT_FAST_PERCENT ) / 100UL;
244 0 : ulong max_allowable_drift_slow = fd_ulong_sat_mul( poh_estimate_offset, MAX_ALLOWABLE_DRIFT_SLOW_PERCENT ) / 100UL;
245 :
246 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/stake_weighted_timestamp.rs#L82-L98 */
247 0 : if( estimate_offset>poh_estimate_offset && fd_ulong_sat_sub( estimate_offset, poh_estimate_offset )>max_allowable_drift_slow ) {
248 0 : estimate = fd_long_sat_add(
249 0 : epoch_start_timestamp,
250 0 : fd_long_sat_add( (long)poh_estimate_offset / NS_IN_S, (long)max_allowable_drift_slow / NS_IN_S ) );
251 0 : } else if( estimate_offset<poh_estimate_offset && fd_ulong_sat_sub( poh_estimate_offset, estimate_offset )>max_allowable_drift_fast ) {
252 0 : estimate = fd_long_sat_sub(
253 0 : fd_long_sat_add( epoch_start_timestamp, (long)poh_estimate_offset / NS_IN_S ),
254 0 : (long)max_allowable_drift_fast / NS_IN_S );
255 0 : }
256 :
257 0 : return estimate;
258 0 : }
259 :
260 : /* TODO: This function should be called from genesis bootup as well with
261 : parent_epoch = NULL
262 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2158-L2215 */
263 : void
264 : fd_sysvar_clock_update( fd_bank_t * bank,
265 : fd_accdb_user_t * accdb,
266 : fd_funk_txn_xid_t const * xid,
267 : fd_capture_ctx_t * capture_ctx,
268 : fd_runtime_stack_t * runtime_stack,
269 0 : ulong const * parent_epoch ) {
270 0 : fd_sol_sysvar_clock_t clock_[1];
271 0 : fd_sol_sysvar_clock_t * clock = fd_sysvar_clock_read( accdb->funk, xid, clock_ );
272 0 : if( FD_UNLIKELY( !clock ) ) FD_LOG_ERR(( "fd_sysvar_clock_read failed" ));
273 :
274 0 : fd_epoch_schedule_t const * epoch_schedule = fd_bank_epoch_schedule_query( bank );
275 0 : ulong current_slot = fd_bank_slot_get( bank );
276 0 : ulong current_epoch = fd_slot_to_epoch( epoch_schedule, current_slot, NULL );
277 :
278 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2159 */
279 0 : long unix_timestamp = clock->unix_timestamp;
280 :
281 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2175 */
282 0 : long ancestor_timestamp = clock->unix_timestamp;
283 :
284 : /* TODO: Are we handling slot 0 correctly?
285 : https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2176-L2183 */
286 0 : long timestamp_estimate = get_timestamp_estimate( bank, clock, runtime_stack );
287 :
288 : /* If the timestamp was successfully calculated, use it. It not keep the old one. */
289 0 : if( FD_LIKELY( timestamp_estimate!=0L ) ) {
290 0 : unix_timestamp = timestamp_estimate;
291 :
292 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2180-L2182 */
293 0 : if( timestamp_estimate<ancestor_timestamp ) {
294 0 : unix_timestamp = ancestor_timestamp;
295 0 : }
296 0 : }
297 :
298 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2191-L2197 */
299 0 : long epoch_start_timestamp = (parent_epoch!=NULL && *parent_epoch!=current_epoch) ?
300 0 : unix_timestamp :
301 0 : clock->epoch_start_timestamp;
302 :
303 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2198-L2201 */
304 0 : if( FD_UNLIKELY( current_slot==0UL ) ) {
305 0 : long timestamp_from_genesis = unix_timestamp_from_genesis( bank );
306 0 : unix_timestamp = timestamp_from_genesis;
307 0 : epoch_start_timestamp = timestamp_from_genesis;
308 0 : }
309 :
310 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2202-L2208 */
311 0 : *clock = (fd_sol_sysvar_clock_t){
312 0 : .slot = current_slot,
313 0 : .epoch_start_timestamp = epoch_start_timestamp,
314 0 : .epoch = current_epoch,
315 0 : .leader_schedule_epoch = fd_slot_to_leader_schedule_epoch( epoch_schedule, current_slot ),
316 0 : .unix_timestamp = unix_timestamp,
317 0 : };
318 :
319 : /* https://github.com/anza-xyz/agave/blob/v2.3.7/runtime/src/bank.rs#L2209-L2214 */
320 0 : fd_sysvar_clock_write( bank, accdb, xid, capture_ctx, clock );
321 0 : }
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