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248 | @pytest.mark.parametrize("depth", [1, 64, 256])
@pytest.mark.parametrize("mem_size", [0, 8 * 1024, 64 * 1024])
def test_nested_frame_memory(
benchmark_test: BenchmarkTestFiller,
pre: Alloc,
fork: Fork,
gas_benchmark_value: int,
tx_gas_limit: int,
depth: int,
mem_size: int,
) -> None:
"""Benchmark a deep frame stack where every frame holds live memory."""
leaf_address = pre.deploy_contract(
code=WhileGas(body=Op.POP(Op.MLOAD(Op.PUSH0)), fork=fork)
)
# The frame's own memory is claimed before the descent, and must not
# overlap memory[0:32], which carries the depth to the next frame.
frame_memory = (
Op.MSTORE8(mem_size - 1, 0xFF) if mem_size > 0 else Bytecode()
)
descend = Op.MSTORE(0, Op.SUB(Op.CALLDATALOAD(0), 1)) + Conditional(
condition=Op.CALL(
gas=Op.GAS,
address=Op.ADDRESS,
args_offset=0,
args_size=32,
address_warm=True,
),
if_false=Op.REVERT(0, 0),
)
frame_code = frame_memory + Conditional(
condition=Op.ISZERO(Op.CALLDATALOAD(0)),
if_true=Op.POP(Op.CALL(gas=Op.GAS, address=leaf_address)),
if_false=descend,
)
entry_address = pre.deploy_contract(code=frame_code)
# gas_cost counts both Conditional branches and a cold leaf CALL,
# so the estimate is conservative and the clamp errs shallow.
mem_expansion = fork.memory_expansion_gas_calculator()
frame_gas = frame_code.gas_cost(fork) + mem_expansion(new_bytes=mem_size)
def reachable_depth(execution_gas: int) -> int:
"""Return the deepest frame the budget can fund."""
frames = 0
while True:
forwarded_gas = execution_gas - frame_gas
forwarded_gas -= forwarded_gas // 64
if forwarded_gas < frame_gas:
return frames
execution_gas = forwarded_gas
frames += 1
intrinsic_gas = fork.transaction_intrinsic_cost_calculator()(
calldata=b"\xff" * 32,
return_cost_deducted_prior_execution=True,
)
txs = []
remaining_gas = gas_benchmark_value
while remaining_gas > 0:
execution_gas = min(tx_gas_limit, remaining_gas)
remaining_gas -= execution_gas
if execution_gas < intrinsic_gas + frame_gas:
break
txs.append(
Transaction(
to=entry_address,
gas_limit=execution_gas,
data=Hash(
min(
depth,
reachable_depth(execution_gas - intrinsic_gas),
)
),
sender=pre.fund_eoa(),
)
)
benchmark_test(
blocks=[Block(txs=txs)],
skip_gas_used_validation=True,
verifications=[ReceiptStatusExpected()],
)
|