Time & Sysvars
Methods for manipulating time and system variables
Time Manipulation
warp_to_slot
pub fn warp_to_slot(&mut self, slot: u64)
Jump to a specific slot. Only forward time travel is supported.
// Get current slot
let clock: Clock = svm.get_sysvar();
let current_slot = clock.slot;
// Jump forward 100 slots
svm.warp_to_slot(current_slot + 100);
// Verify
let new_clock: Clock = svm.get_sysvar();
assert_eq!(new_clock.slot, current_slot + 100);
Manual Clock Manipulation
use solana_sdk::clock::Clock;
// Read clock
let mut clock: Clock = svm.get_sysvar();
// Modify fields
clock.slot = 1000;
clock.epoch = 10;
clock.unix_timestamp = 1735689600;
// Write back
svm.set_sysvar(&clock);
Use warp_to_slot()
for most time manipulation. Use manual clock modification
only when you need precise control over multiple fields.
Sysvars
get_sysvar
pub fn get_sysvar<T: Sysvar>(&self) -> T
Read sysvar value.
use solana_sdk::clock::Clock;
use solana_sdk::rent::Rent;
use solana_sdk::epoch_schedule::EpochSchedule;
let clock: Clock = svm.get_sysvar();
let rent: Rent = svm.get_sysvar();
let epoch_schedule: EpochSchedule = svm.get_sysvar();
set_sysvar
pub fn set_sysvar<T: Sysvar>(&mut self, sysvar: &T)
Write sysvar value.
use solana_sdk::rent::Rent;
let rent = Rent {
lamports_per_byte_year: 3480,
exemption_threshold: 2.0,
burn_percent: 50,
};
svm.set_sysvar(&rent);
Common Sysvars
Clock
use solana_sdk::clock::Clock;
let clock: Clock = svm.get_sysvar();
println!("Slot: {}", clock.slot);
println!("Timestamp: {}", clock.unix_timestamp);
println!("Epoch: {}", clock.epoch);
Rent
use solana_sdk::rent::Rent;
let rent: Rent = svm.get_sysvar();
let min_balance = rent.minimum_balance(data_len);
Epoch Schedule
use solana_sdk::epoch_schedule::EpochSchedule;
let schedule: EpochSchedule = svm.get_sysvar();
println!("Slots per epoch: {}", schedule.slots_per_epoch);
Stake History
use solana_sdk::stake_history::{StakeHistory, StakeHistoryEntry};
let mut stake_history = StakeHistory::default();
stake_history.add(
0, // epoch
StakeHistoryEntry {
effective: 1_000_000,
activating: 0,
deactivating: 0,
},
);
svm.set_sysvar(&stake_history);
Time-Based Testing Patterns
Test Slot-Based Features
let mut svm = LiteSVM::new();
// Get starting slot
let start_slot = svm.get_sysvar::<Clock>().slot;
// Try action before unlock slot (should fail)
let result = call_locked_program(&mut svm);
assert!(result.is_err());
// Warp to unlock slot
svm.warp_to_slot(start_slot + 1000);
// Now it should succeed
let result = call_locked_program(&mut svm);
assert!(result.is_ok());
Test Timestamp-Based Features
let mut svm = LiteSVM::new();
// Get current timestamp
let clock: Clock = svm.get_sysvar();
let current_time = clock.unix_timestamp;
// Warp forward 1 hour (3600 seconds)
// Slots roughly correspond to ~0.4 seconds on Solana
let target_slot = clock.slot + (3600.0 / 0.4) as u64;
svm.warp_to_slot(target_slot);
// Verify timestamp increased
let new_clock: Clock = svm.get_sysvar();
assert!(new_clock.unix_timestamp >= current_time + 3600);
Test Vesting Schedules
// Setup vesting with 100 slot period
let vesting_period = 100;
let start_slot = svm.get_sysvar::<Clock>().slot;
// Test before vesting completes
let result = claim_vested_tokens(&mut svm);
assert!(result.is_err()); // Too early
// Warp past vesting period
svm.warp_to_slot(start_slot + vesting_period + 1);
// Now claim should succeed
let result = claim_vested_tokens(&mut svm);
assert!(result.is_ok());
Common Use Cases
- Vesting schedules
- Time-locked withdrawals
- Stake/unstake cooldown periods
- Auction end times
- Rental periods
- Epoch-based rewards
Important Notes
- Forward only - You can only warp forward in time, not backward
- Slot to time - Slots roughly correspond to ~0.4 seconds on Solana mainnet
- Clock sysvar - Always updated when using
warp_to_slot()
- No automatic updates - Unlike real validators, time doesn't advance automatically between transactions