test_worst_creates_collisions()

Documentation for tests/benchmark/test_worst_bytecode.py::test_worst_creates_collisions@v5.0.0.

Generate fixtures for these test cases for Osaka with:

fill -v tests/benchmark/test_worst_bytecode.py::test_worst_creates_collisions --fork Osaka

Test the CREATE and CREATE2 collisions performance.

Source code in tests/benchmark/test_worst_bytecode.py

@pytest.mark.valid_from("Cancun")
@pytest.mark.parametrize(
    "opcode",
    [
        Op.CREATE,
        Op.CREATE2,
    ],
)
def test_worst_creates_collisions(
    state_test: StateTestFiller,
    pre: Alloc,
    fork: Fork,
    opcode: Op,
    gas_benchmark_value: int,
):
    """Test the CREATE and CREATE2 collisions performance."""
    # We deploy a "proxy contract" which is the contract that will be called in a loop
    # using all the gas in the block. This "proxy contract" is the one executing CREATE2
    # failing with a collision.
    # The reason why we need a "proxy contract" is that CREATE(2) failing with a collision will
    # consume all the available gas. If we try to execute the CREATE(2) directly without being
    # wrapped **and capped in gas** in a previous CALL, we would run out of gas very fast!
    #
    # The proxy contract calls CREATE(2) with empty initcode. The current call frame gas will
    # be exhausted because of the collision. For this reason the caller will carefully give us
    # the minimal gas necessary to execute the CREATE(2) and not waste any extra gas in the
    # CREATE(2)-failure.
    #
    # Note that these CREATE(2) calls will fail because in (**) below we pre-alloc contracts
    # with the same address as the ones that CREATE(2) will try to create.
    proxy_contract = pre.deploy_contract(
        code=Op.CREATE2(value=Op.PUSH0, salt=Op.PUSH0, offset=Op.PUSH0, size=Op.PUSH0)
        if opcode == Op.CREATE2
        else Op.CREATE(value=Op.PUSH0, offset=Op.PUSH0, size=Op.PUSH0)
    )

    gas_costs = fork.gas_costs()
    # The CALL to the proxy contract needs at a minimum gas corresponding to the CREATE(2)
    # plus extra required PUSH0s for arguments.
    min_gas_required = gas_costs.G_CREATE + gas_costs.G_BASE * (3 if opcode == Op.CREATE else 4)
    code_prefix = Op.PUSH20(proxy_contract) + Op.PUSH3(min_gas_required)
    attack_block = Op.POP(
        # DUP7 refers to the PUSH3 above.
        # DUP7 refers to the proxy contract address.
        Op.CALL(gas=Op.DUP7, address=Op.DUP7)
    )
    code = code_loop_precompile_call(code_prefix, attack_block, fork)
    tx_target = pre.deploy_contract(code=code)

    # (**) We deploy the contract that CREATE(2) will attempt to create so any attempt will fail.
    if opcode == Op.CREATE2:
        addr = compute_create2_address(address=proxy_contract, salt=0, initcode=[])
        pre.deploy_contract(address=addr, code=Op.INVALID)
    else:
        # Heuristic to have an upper bound.
        max_contract_count = 2 * gas_benchmark_value // gas_costs.G_CREATE
        for nonce in range(max_contract_count):
            addr = compute_create_address(address=proxy_contract, nonce=nonce)
            pre.deploy_contract(address=addr, code=Op.INVALID)

    tx = Transaction(
        to=tx_target,
        gas_limit=gas_benchmark_value,
        sender=pre.fund_eoa(),
    )

    state_test(
        pre=pre,
        post={},
        tx=tx,
    )

Parametrized Test Cases

The interactive table below is also available as a standalone page.

Fork All Forks Cancun Prague Osaka

Fixture Type All Fixture Types state_test blockchain_test

Test ID (Abbreviated)	opcode
...fork_Cancun-state_test-opcode_CREATE	CREATE
...fork_Cancun-state_test-opcode_CREATE2	CREATE2
...fork_Cancun-blockchain_test_from_state_test-opcode_CREATE	CREATE
...fork_Cancun-blockchain_test_from_state_test-opcode_CREATE2	CREATE2
...fork_Prague-state_test-opcode_CREATE	CREATE
...fork_Prague-state_test-opcode_CREATE2	CREATE2
...fork_Prague-blockchain_test_from_state_test-opcode_CREATE	CREATE
...fork_Prague-blockchain_test_from_state_test-opcode_CREATE2	CREATE2
...fork_Osaka-state_test-opcode_CREATE	CREATE
...fork_Osaka-state_test-opcode_CREATE2	CREATE2
...fork_Osaka-blockchain_test_from_state_test-opcode_CREATE	CREATE
...fork_Osaka-blockchain_test_from_state_test-opcode_CREATE2	CREATE2