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// Copyright 2021-2023 Protocol Labs
// SPDX-License-Identifier: Apache-2.0, MIT
use std::rc::Rc;
use anyhow::{anyhow, Context};
use cid::Cid;
use derive_more::{Deref, DerefMut};
use fvm_ipld_amt::Amt;
use fvm_ipld_encoding::{to_vec, CBOR};
use fvm_shared::address::{Address, Payload};
use fvm_shared::econ::TokenAmount;
use fvm_shared::error::{ErrorNumber, ExitCode};
use fvm_shared::event::StampedEvent;
use fvm_shared::sys::BlockId;
use fvm_shared::{ActorID, METHOD_SEND};
use num_traits::Zero;
use super::state_access_tracker::{ActorAccessState, StateAccessTracker};
use super::{Backtrace, CallManager, Entrypoint, InvocationResult, NO_DATA_BLOCK_ID};
use crate::blockstore::DiscardBlockstore;
use crate::call_manager::backtrace::Frame;
use crate::call_manager::FinishRet;
use crate::eam_actor::EAM_ACTOR_ID;
use crate::engine::Engine;
use crate::gas::{Gas, GasTracker};
use crate::kernel::{
Block, BlockRegistry, ClassifyResult, ExecutionError, Kernel, Result, SyscallError,
};
use crate::machine::limiter::MemoryLimiter;
use crate::machine::Machine;
use crate::state_tree::ActorState;
use crate::syscalls::error::Abort;
use crate::syscalls::{charge_for_exec, update_gas_available};
use crate::trace::{ExecutionEvent, ExecutionTrace};
use crate::{syscall_error, system_actor};
/// The default [`CallManager`] implementation.
#[repr(transparent)]
pub struct DefaultCallManager<M: Machine>(Option<Box<InnerDefaultCallManager<M>>>);
#[doc(hidden)]
#[derive(Deref, DerefMut)]
pub struct InnerDefaultCallManager<M: Machine> {
/// The machine this kernel is attached to.
#[deref]
#[deref_mut]
machine: M,
/// The engine with which to execute the message.
engine: Rc<Engine>,
/// The gas tracker.
gas_tracker: GasTracker,
/// The state-access tracker that helps us charge gas for actor-state lookups/updates and actor
/// address resolutions.
state_access_tracker: StateAccessTracker,
/// The gas premium paid by this message.
gas_premium: TokenAmount,
/// The ActorID and the address of the original sender of the chain message that initiated
/// this call stack.
origin: ActorID,
/// The origin address as specified in the message (used to derive new f2 addresses).
origin_address: Address,
/// The nonce of the chain message that initiated this call stack.
nonce: u64,
/// Number of actors created in this call stack.
num_actors_created: u64,
/// Current call-stack depth.
call_stack_depth: u32,
/// The current chain of errors, if any.
backtrace: Backtrace,
/// The current execution trace.
exec_trace: ExecutionTrace,
/// Number of actors that have been invoked in this message execution.
invocation_count: u64,
/// Limits on memory throughout the execution.
limits: M::Limiter,
/// Accumulator for events emitted in this call stack.
events: EventsAccumulator,
/// The actor call stack (ActorID and entrypoint name tuple).
actor_call_stack: Vec<(ActorID, &'static str)>,
}
#[doc(hidden)]
impl<M: Machine> std::ops::Deref for DefaultCallManager<M> {
type Target = InnerDefaultCallManager<M>;
fn deref(&self) -> &Self::Target {
self.0.as_ref().expect("call manager is poisoned")
}
}
#[doc(hidden)]
impl<M: Machine> std::ops::DerefMut for DefaultCallManager<M> {
fn deref_mut(&mut self) -> &mut Self::Target {
self.0.as_mut().expect("call manager is poisoned")
}
}
impl<M> CallManager for DefaultCallManager<M>
where
M: Machine,
{
type Machine = M;
fn new(
machine: M,
engine: Engine,
gas_limit: u64,
origin: ActorID,
origin_address: Address,
receiver: Option<ActorID>,
receiver_address: Address,
nonce: u64,
gas_premium: TokenAmount,
) -> Self {
let limits = machine.new_limiter();
let gas_tracker =
GasTracker::new(Gas::new(gas_limit), Gas::zero(), machine.context().tracing);
let state_access_tracker =
StateAccessTracker::new(&machine.context().price_list.preloaded_actors);
/* Origin */
// - We don't charge for looking up the message's origin (assumed to be done ahead of time
// and in parallel.
// - We've already charged for updating the message's origin in preflight.
state_access_tracker.record_actor_update(origin);
// Treat the top-level origin and sender as "already charged".
state_access_tracker.record_lookup_address(&origin_address);
/* Receiver */
// Treat the top-level as "preloaded", if it exists. The executor will have pre-resolved
// this address, if possible.
if let Some(receiver_id) = receiver {
state_access_tracker.record_actor_read(receiver_id)
}
// Avoid charging for any subsequent lookups. If the receiver _doesn't_ exist, we'll end up
// charging to assign the address (one address lookup + update charge), but that's a
// different matter.
//
// NOTE: Technically, we should be _caching_ the existence of the receiver, so we can skip
// this step on `call_actor` and create the target actor immediately. By not doing that, we're not
// being perfectly efficient and are technically under-charging gas. HOWEVER, this behavior
// cannot be triggered by an actor on-chain, so it's not a concern (for now).
state_access_tracker.record_lookup_address(&receiver_address);
DefaultCallManager(Some(Box::new(InnerDefaultCallManager {
engine: Rc::new(engine),
machine,
gas_tracker,
gas_premium,
origin,
origin_address,
nonce,
num_actors_created: 0,
call_stack_depth: 0,
backtrace: Backtrace::default(),
exec_trace: vec![],
invocation_count: 0,
limits,
events: Default::default(),
state_access_tracker,
actor_call_stack: vec![],
})))
}
fn limiter_mut(&mut self) -> &mut <Self::Machine as Machine>::Limiter {
&mut self.limits
}
fn call_actor<K>(
&mut self,
from: ActorID,
to: Address,
entrypoint: Entrypoint,
params: Option<Block>,
value: &TokenAmount,
gas_limit: Option<Gas>,
read_only: bool,
) -> Result<InvocationResult>
where
K: Kernel<CallManager = Self>,
{
if self.machine.context().tracing {
if let Entrypoint::Invoke(method) = &entrypoint {
self.trace(ExecutionEvent::Call {
from,
to,
method: *method,
params: params.as_ref().map(Into::into),
value: value.clone(),
gas_limit: std::cmp::min(
gas_limit.unwrap_or(Gas::from_milligas(u64::MAX)).round_up(),
self.gas_tracker.gas_available().round_up(),
),
read_only,
});
}
}
// If a specific gas limit has been requested, push a new limit into the gas tracker.
if let Some(limit) = gas_limit {
self.gas_tracker.push_limit(limit);
}
let mut result = self.with_stack_frame(|s| {
s.call_actor_unchecked::<K>(from, to, entrypoint, params, value, read_only)
});
// If we pushed a limit, pop it.
if gas_limit.is_some() {
self.gas_tracker.pop_limit()?;
}
// If we're not out of gas but the error is "out of gas" (e.g., due to a gas limit), replace
// the error with an explicit exit code.
if !self.gas_tracker.gas_available().is_zero()
&& matches!(result, Err(ExecutionError::OutOfGas))
{
result = Ok(InvocationResult {
exit_code: ExitCode::SYS_OUT_OF_GAS,
value: None,
})
}
if self.machine.context().tracing && matches!(entrypoint, Entrypoint::Invoke(_)) {
self.trace(match &result {
Ok(InvocationResult { exit_code, value }) => {
ExecutionEvent::CallReturn(*exit_code, value.as_ref().map(Into::into))
}
Err(ExecutionError::OutOfGas) => {
ExecutionEvent::CallReturn(ExitCode::SYS_OUT_OF_GAS, None)
}
Err(ExecutionError::Fatal(_)) => {
ExecutionEvent::CallError(SyscallError::new(ErrorNumber::Forbidden, "fatal"))
}
Err(ExecutionError::Syscall(s)) => ExecutionEvent::CallError(s.clone()),
});
}
result
}
fn with_transaction(
&mut self,
f: impl FnOnce(&mut Self) -> Result<InvocationResult>,
) -> Result<InvocationResult> {
self.state_tree_mut().begin_transaction();
self.events.begin_transaction();
self.state_access_tracker.begin_transaction();
let (revert, res) = match f(self) {
Ok(v) => (!v.exit_code.is_success(), Ok(v)),
Err(e) => (true, Err(e)),
};
self.state_tree_mut().end_transaction(revert)?;
self.events.end_transaction(revert)?;
self.state_access_tracker.end_transaction(revert)?;
res
}
fn finish(mut self) -> (Result<FinishRet>, Self::Machine) {
let InnerDefaultCallManager {
machine,
backtrace,
gas_tracker,
mut exec_trace,
events,
..
} = *self.0.take().expect("call manager is poisoned");
let gas_used = gas_tracker.gas_used().round_up();
// Finalize any trace events, if we're tracing.
if machine.context().tracing {
exec_trace.extend(gas_tracker.drain_trace().map(ExecutionEvent::GasCharge));
}
let res = events.finish();
let Events {
events,
root: events_root,
} = match res {
Ok(events) => events,
Err(err) => return (Err(err), machine),
};
(
Ok(FinishRet {
gas_used,
backtrace,
exec_trace,
events,
events_root,
}),
machine,
)
}
// Accessor methods so the trait can implement some common methods by default.
fn machine(&self) -> &Self::Machine {
&self.machine
}
fn machine_mut(&mut self) -> &mut Self::Machine {
&mut self.machine
}
fn engine(&self) -> &Engine {
&self.engine
}
fn gas_tracker(&self) -> &GasTracker {
&self.gas_tracker
}
fn gas_premium(&self) -> &TokenAmount {
&self.gas_premium
}
// Other accessor methods
fn origin(&self) -> ActorID {
self.origin
}
fn nonce(&self) -> u64 {
self.nonce
}
fn get_call_stack(&self) -> &[(ActorID, &'static str)] {
&self.actor_call_stack
}
fn next_actor_address(&self) -> Address {
// Base the next address on the address specified as the message origin. This lets us use,
// e.g., an f2 address even if we can't look it up anywhere.
//
// Of course, if the user decides to send from an f0 address without waiting for finality,
// their "stable" address may not be as stable as they'd like. But that's their problem.
//
// In case you're wondering: but what if someone _else_ is relying on the stability of this
// address? They shouldn't be. The sender can always _replace_ a message with a new message,
// and completely change how f2 addresses are assigned. Only the message sender can rely on
// an f2 address (before finality).
let mut b = to_vec(&self.origin_address).expect("failed to serialize address");
b.extend_from_slice(&self.nonce.to_be_bytes());
b.extend_from_slice(&self.num_actors_created.to_be_bytes());
Address::new_actor(&b)
}
fn create_actor(
&mut self,
code_id: Cid,
actor_id: ActorID,
delegated_address: Option<Address>,
) -> Result<()> {
if self.machine.builtin_actors().is_placeholder_actor(&code_id) {
return Err(syscall_error!(
Forbidden,
"cannot explicitly construct a placeholder actor"
)
.into());
}
// Check to make sure the actor doesn't exist, or is a placeholder.
let actor = match self.get_actor(actor_id)? {
// Replace the placeholder
Some(mut act)
if self
.machine
.builtin_actors()
.is_placeholder_actor(&act.code) =>
{
if act.delegated_address.is_none() {
// The FVM made a mistake somewhere.
return Err(ExecutionError::Fatal(anyhow!(
"placeholder {actor_id} doesn't have a delegated address"
)));
}
if act.delegated_address != delegated_address {
// The Init actor made a mistake?
return Err(syscall_error!(
Forbidden,
"placeholder has a different delegated address"
)
.into());
}
act.code = code_id;
act
}
// Don't replace anything else.
Some(_) => {
return Err(syscall_error!(Forbidden; "Actor address already exists").into());
}
// Create a new actor.
None => {
// We charge for creating the actor (storage) but not for address assignment as the
// init actor has already handled that for us.
self.charge_gas(self.price_list().on_create_actor(false))?;
ActorState::new_empty(code_id, delegated_address)
}
};
self.set_actor(actor_id, actor)?;
self.num_actors_created += 1;
Ok(())
}
fn append_event(&mut self, evt: StampedEvent) {
self.events.append_event(evt)
}
// Helper for creating actors. This really doesn't belong on this trait.
fn invocation_count(&self) -> u64 {
self.invocation_count
}
/// Resolve an address and charge for it.
fn resolve_address(&self, address: &Address) -> Result<Option<ActorID>> {
if let Ok(id) = address.id() {
return Ok(Some(id));
}
if !self.state_access_tracker.get_address_lookup_state(address) {
self.gas_tracker
.apply_charge(self.price_list().on_resolve_address())?;
}
let id = self.state_tree().lookup_id(address)?;
if id.is_some() {
self.state_access_tracker.record_lookup_address(address);
}
Ok(id)
}
fn get_actor(&self, id: ActorID) -> Result<Option<ActorState>> {
let access = self.state_access_tracker.get_actor_access_state(id);
if access < Some(ActorAccessState::Read) {
self.gas_tracker
.apply_charge(self.price_list().on_actor_lookup())?;
}
let actor = self.state_tree().get_actor(id)?;
self.state_access_tracker.record_actor_read(id);
Ok(actor)
}
fn set_actor(&mut self, id: ActorID, state: ActorState) -> Result<()> {
let access = self.state_access_tracker.get_actor_access_state(id);
if access < Some(ActorAccessState::Read) {
self.gas_tracker
.apply_charge(self.price_list().on_actor_lookup())?;
}
if access < Some(ActorAccessState::Updated) {
self.gas_tracker
.apply_charge(self.price_list().on_actor_update())?;
}
self.state_tree_mut().set_actor(id, state);
self.state_access_tracker.record_actor_update(id);
Ok(())
}
fn delete_actor(&mut self, id: ActorID) -> Result<()> {
let access = self.state_access_tracker.get_actor_access_state(id);
if access < Some(ActorAccessState::Read) {
self.gas_tracker
.apply_charge(self.price_list().on_actor_lookup())?;
}
if access < Some(ActorAccessState::Updated) {
self.gas_tracker
.apply_charge(self.price_list().on_actor_update())?;
}
self.state_tree_mut().delete_actor(id);
self.state_access_tracker.record_actor_update(id);
Ok(())
}
fn transfer(&mut self, from: ActorID, to: ActorID, value: &TokenAmount) -> Result<()> {
if value.is_negative() {
return Err(syscall_error!(IllegalArgument;
"attempted to transfer negative transfer value {}", value)
.into());
}
// If the from actor doesn't exist, we return "insufficient funds" to distinguish between
// that and the case where the _receiving_ actor doesn't exist.
let mut from_actor = self
.get_actor(from)?
.ok_or_else(||syscall_error!(InsufficientFunds; "insufficient funds to transfer {value}FIL from {from} to {to})"))?;
if &from_actor.balance < value {
return Err(syscall_error!(InsufficientFunds; "sender does not have funds to transfer (balance {}, transfer {})", &from_actor.balance, value).into());
}
if from == to {
log::debug!("attempting to self-transfer: noop (from/to: {})", from);
return Ok(());
}
let mut to_actor = self.get_actor(to)?.ok_or_else(
|| syscall_error!(NotFound; "transfer recipient {to} does not exist in state-tree"),
)?;
// We've already checked the balances/value, so any errors here are fatal.
from_actor.deduct_funds(value).or_fatal()?;
to_actor.deposit_funds(value).or_fatal()?;
self.set_actor(from, from_actor)?;
self.set_actor(to, to_actor)?;
log::trace!("transferred {} from {} to {}", value, from, to);
Ok(())
}
}
impl<M> DefaultCallManager<M>
where
M: Machine,
{
fn trace(&mut self, trace: ExecutionEvent) {
// The price of deref magic is that you sometimes need to tell the compiler: no, this is
// fine.
let s = &mut **self;
s.exec_trace
.extend(s.gas_tracker.drain_trace().map(ExecutionEvent::GasCharge));
s.exec_trace.push(trace);
}
/// Helper method to create an uninitialized actor due to a send.
fn create_actor_from_send(&mut self, addr: &Address, act: ActorState) -> Result<ActorID> {
// This will charge for the address assignment and the actor storage, but not the actor
// lookup/update (charged below in `set_actor`).
self.charge_gas(self.price_list().on_create_actor(true))?;
let addr_id = self.state_tree_mut().register_new_address(addr)?;
self.state_access_tracker.record_lookup_address(addr);
// Now we actually set the actor state, charging for reads/writes as necessary and recording
// the fact that the actor has been updated.
self.set_actor(addr_id, act)?;
Ok(addr_id)
}
/// Helper method to create an f1/f3 account actor due to a send. This method:
///
/// 1. Creates the actor.
/// 2. Initializes it by calling the constructor.
fn create_account_actor_from_send<K>(&mut self, addr: &Address) -> Result<ActorID>
where
K: Kernel<CallManager = Self>,
{
if addr.is_bls_zero_address() {
return Err(
syscall_error!(IllegalArgument; "cannot create the bls zero address actor").into(),
);
}
// Create the actor in the state tree.
let id = {
let code_cid = self.builtin_actors().get_account_code();
let state = ActorState::new_empty(*code_cid, None);
self.create_actor_from_send(addr, state)?
};
// Now invoke the constructor; first create the parameters, then
// instantiate a new kernel to invoke the constructor.
let params = to_vec(&addr).map_err(|e| {
// This shouldn't happen, but we treat it as an illegal argument error and move on.
// It _likely_ means that the inputs were invalid in some unexpected way.
log::error!(
"failed to serialize address when creating actor, ignoring: {}",
e
);
syscall_error!(IllegalArgument; "failed to serialize params: {}", e)
})?;
self.call_actor_resolved::<K>(
system_actor::SYSTEM_ACTOR_ID,
id,
Entrypoint::ImplicitConstructor,
Some(Block::new(CBOR, params, Vec::new())),
&TokenAmount::zero(),
false,
)?;
Ok(id)
}
/// Helper method to create a placeholder actor due to a send. This method does not execute any
/// constructors.
fn create_placeholder_actor_from_send(&mut self, addr: &Address) -> Result<ActorID> {
let code_cid = self.builtin_actors().get_placeholder_code();
let state = ActorState::new_empty(*code_cid, Some(*addr));
self.create_actor_from_send(addr, state)
}
/// Call actor without checking the call depth and/or dealing with transactions. This must _only_ be
/// called from `call_actor`.
fn call_actor_unchecked<K>(
&mut self,
from: ActorID,
to: Address,
entrypoint: Entrypoint,
params: Option<Block>,
value: &TokenAmount,
read_only: bool,
) -> Result<InvocationResult>
where
K: Kernel<CallManager = Self>,
{
// Get the receiver; this will resolve the address.
let to = match self.resolve_address(&to)? {
Some(addr) => addr,
None => match to.payload() {
Payload::BLS(_) | Payload::Secp256k1(_) => {
if read_only {
return Err(syscall_error!(ReadOnly; "cannot auto-create account {to} in read-only calls").into());
}
// Try to create an account actor if the receiver is a key address.
self.create_account_actor_from_send::<K>(&to)?
}
// Validate that there's an actor at the target ID (we don't care what is there,
// just that something is there).
Payload::Delegated(da) if da.namespace() == EAM_ACTOR_ID => {
if read_only {
return Err(syscall_error!(ReadOnly; "cannot auto-create account {to} in read-only calls").into());
}
self.create_placeholder_actor_from_send(&to)?
}
_ => return Err(
syscall_error!(NotFound; "actor does not exist or cannot be created: {}", to)
.into(),
),
},
};
self.actor_call_stack.push((to, entrypoint.func_name()));
let res = self.call_actor_resolved::<K>(from, to, entrypoint, params, value, read_only);
self.actor_call_stack.pop();
res
}
/// Call actor with resolved addresses.
fn call_actor_resolved<K>(
&mut self,
from: ActorID,
to: ActorID,
entrypoint: Entrypoint,
params: Option<Block>,
value: &TokenAmount,
read_only: bool,
) -> Result<InvocationResult>
where
K: Kernel<CallManager = Self>,
{
// Lookup the actor.
let state = self
.get_actor(to)?
.ok_or_else(|| syscall_error!(NotFound; "actor does not exist: {}", to))?;
// We're only tracing explicit "invokes" (no upgrades or implicit constructions, for now) as
// we want to be able to pair the invoke with another event in the trace. I.e. call ->
// invoke, upgrade -> invoke, construct -> invoke.
//
// Once we add tracing support for upgrades, we can start recording those actor invocations
// as well.
if self.machine.context().tracing && matches!(entrypoint, Entrypoint::Invoke(_)) {
self.trace(ExecutionEvent::InvokeActor {
id: to,
state: state.clone(),
});
}
// Transfer, if necessary.
if !value.is_zero() {
let t = self.charge_gas(self.price_list().on_value_transfer())?;
self.transfer(from, to, value)?;
t.stop();
}
// Abort early if we have a send.
if entrypoint.invokes(METHOD_SEND) {
log::trace!("sent {} -> {}: {}", from, to, &value);
return Ok(InvocationResult::default());
}
// Charge the invocation gas.
let (param_size, param_link_count) = params
.as_ref()
.map(|p| (p.size(), p.links().len()))
.unwrap_or_default();
let t = self.charge_gas(
self.price_list()
.on_method_invocation(param_size, param_link_count),
)?;
// Store the parametrs, and initialize the block registry for the target actor.
let mut block_registry = BlockRegistry::new();
let params_id = if let Some(blk) = params {
block_registry.put_reachable(blk)?
} else {
NO_DATA_BLOCK_ID
};
// additional_params takes care of adding entrypoint specific params to the block
// registry and passing them to wasmtime
let additional_params = entrypoint.into_params(&mut block_registry)?;
// Increment invocation count
self.invocation_count += 1;
// Ensure that actor's code is loaded and cached in the engine.
// NOTE: this does not cover the EVM smart contract actor, which is a built-in actor, is
// listed the manifest, and therefore preloaded during system initialization.
#[cfg(feature = "m2-native")]
self.engine
.preload(&state.code, self.blockstore())
.map_err(
|_| syscall_error!(NotFound; "actor code cid does not exist {}", &state.code),
)?;
log::trace!("calling {} -> {}::{}", from, to, entrypoint);
self.map_mut(|cm| {
let engine = cm.engine.clone(); // reference the RC.
// Make the kernel.
let kernel = K::new(
cm,
block_registry,
from,
to,
entrypoint.method_num(),
value.clone(),
read_only,
);
// Make a store.
let mut store = engine.new_store(kernel);
// From this point on, there are no more syscall errors, only aborts.
let result: std::result::Result<BlockId, Abort> = (|| {
let code = &state.code;
// Instantiate the module.
let instance = engine
.instantiate(&mut store, code)?
.context("actor not found")
.map_err(Abort::Fatal)?;
// Resolve and store a reference to the exported memory.
let memory = instance
.get_memory(&mut store, "memory")
.context("actor has no memory export")
.map_err(Abort::Fatal)?;
store.data_mut().memory = memory;
let func = match instance.get_func(&mut store, entrypoint.func_name()) {
Some(func) => func,
None => {
return Err(Abort::Exit(
ExitCode::SYS_INVALID_RECEIVER,
format!("cannot upgrade to {code}"),
0,
));
}
};
let mut params = vec![wasmtime::Val::I32(params_id as i32)];
params.extend_from_slice(additional_params.as_slice());
// Set the available gas.
update_gas_available(&mut store)?;
let mut out = [wasmtime::Val::I32(0)];
let res = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| {
func.call(&mut store, params.as_slice(), &mut out)
}))
.map_err(|panic| Abort::Fatal(anyhow!("panic within actor: {:?}", panic)))?;
// Charge for any remaining uncharged execution gas, returning an error if we run
// out.
charge_for_exec(&mut store)?;
// If the invocation failed due to running out of exec_units, we have already
// detected it and returned OutOfGas above. Any other invocation failure is returned
// here as an Abort
match res {
Ok(_) => Ok(out[0].unwrap_i32() as u32),
Err(e) => Err(e.into()),
}
})();
let invocation_data = store.into_data();
let last_error = invocation_data.last_error;
let (mut cm, block_registry) = invocation_data.kernel.into_inner();
// Resolve the return block's ID into an actual block, converting to an abort if it
// doesn't exist.
let result = result.and_then(|ret_id| {
Ok(if ret_id == NO_DATA_BLOCK_ID {
None
} else {
Some(block_registry.get(ret_id).map_err(|_| {
Abort::Exit(
ExitCode::SYS_MISSING_RETURN,
String::from("returned block does not exist"),
NO_DATA_BLOCK_ID,
)
})?)
})
});
// Process the result, updating the backtrace if necessary.
let mut ret = match result {
Ok(ret) => Ok(InvocationResult {
exit_code: ExitCode::OK,
value: ret.cloned(),
}),
Err(abort) => {
let (code, message, res) = match abort {
Abort::Exit(code, message, NO_DATA_BLOCK_ID) => (
code,
message,
Ok(InvocationResult {
exit_code: code,
value: None,
}),
),
Abort::Exit(code, message, blk_id) => match block_registry.get(blk_id) {
Err(e) => (
ExitCode::SYS_MISSING_RETURN,
"error getting exit data block".to_owned(),
Err(ExecutionError::Fatal(anyhow!(e))),
),
Ok(blk) => (
code,
message,
Ok(InvocationResult {
exit_code: code,
value: Some(blk.clone()),
}),
),
},
Abort::OutOfGas => (
ExitCode::SYS_OUT_OF_GAS,
"out of gas".to_owned(),
Err(ExecutionError::OutOfGas),
),
Abort::Fatal(err) => (
ExitCode::SYS_ASSERTION_FAILED,
"fatal error".to_owned(),
Err(ExecutionError::Fatal(err)),
),
};
if !code.is_success() {
// Only record backtrace frames for explicit messages sent by the user. We
// may want to record frames for failed upgrades, but that complicates
// things a bit and I'd like to keep this API the same for now.
if let &Entrypoint::Invoke(method) = &entrypoint {
if let Some(err) = last_error {
cm.backtrace.begin(err);
}
cm.backtrace.push_frame(Frame {
source: to,
method,
message,
code,
});
}
}
res
}
};
// Charge for the return value if we're returning to the chain itself. In the (near)
// future, we'll charge for internal returns as well (to charge for link tracking).
// Unfortunately, we have to do this _here_ instead of in the caller as we need to apply
// the call's gas limit.
if let Some((ret_size, link_count)) = ret
.as_ref()
.ok()
.and_then(|r| r.value.as_ref())
.map(|v| (v.size(), v.links().len()))
{
if let Err(e) = cm.charge_gas(cm.price_list().on_method_return(
cm.call_stack_depth,
ret_size,
link_count,
)) {
ret = Err(e);
}
}
// Log the results if tracing is enabled.
if log::log_enabled!(log::Level::Trace) {
match &ret {
Ok(val) => log::trace!(
"returning {}::{} -> {} ({})",
to,
entrypoint,
from,
val.exit_code
),
Err(e) => log::trace!("failing {}::{} -> {} (err:{})", to, entrypoint, from, e),
}
}
t.stop();
(ret, cm)
})
}
/// Temporarily replace `self` with a version that contains `None` for the inner part,
/// to be able to hand over ownership of `self` to a new kernel, while the older kernel
/// has a reference to the hollowed out version.
fn map_mut<F, T>(&mut self, f: F) -> T
where
F: FnOnce(Self) -> (T, Self),
{
replace_with::replace_with_and_return(self, || DefaultCallManager(None), f)
}
/// Check that we're not violating the call stack depth, then envelope a call
/// with an increase/decrease of the depth to make sure none of them are missed.
fn with_stack_frame<F, V>(&mut self, f: F) -> Result<V>
where
F: FnOnce(&mut Self) -> Result<V>,
{
if self.call_stack_depth >= self.machine.context().max_call_depth {
return Err(
syscall_error!(LimitExceeded, "message execution exceeds call depth").into(),
);
}
self.call_stack_depth += 1;
let res =
<<<DefaultCallManager<M> as CallManager>::Machine as Machine>::Limiter>::with_stack_frame(
self,
|s| s.limiter_mut(),
f,
);
self.call_stack_depth -= 1;
res
}
}
/// Stores events in layers as they are emitted by actors. As the call stack progresses, when an
/// actor exits normally, its events should be merged onto the previous layer (merge_last_layer).
/// If an actor aborts, the last layer should be discarded (discard_last_layer). This will also
/// throw away any events collected from subcalls (and previously merged, as those subcalls returned
/// normally).
pub struct EventsAccumulator {
events: Vec<StampedEvent>,
idxs: Vec<usize>,
}
impl Default for EventsAccumulator {
fn default() -> Self {
// Pre-allocate some space here for more consistent performance. We only do this once per
// message so the overhead is minimal.
Self {
events: Vec::with_capacity(128),
idxs: Vec::with_capacity(8),
}
}
}
pub(crate) struct Events {
root: Option<Cid>,
events: Vec<StampedEvent>,
}
impl EventsAccumulator {
fn append_event(&mut self, evt: StampedEvent) {
self.events.push(evt)
}
fn begin_transaction(&mut self) {
self.idxs.push(self.events.len());
}
fn end_transaction(&mut self, revert: bool) -> Result<()> {
let idx = self.idxs.pop().ok_or_else(|| {
ExecutionError::Fatal(anyhow!(
"no index in the event accumulator when ending a transaction"
))
})?;
if revert {
self.events.truncate(idx);
}
Ok(())
}
fn finish(self) -> Result<Events> {
if !self.idxs.is_empty() {
return Err(ExecutionError::Fatal(anyhow!(
"bad events accumulator state; expected layer indices to be empty, had {} items",
self.idxs.len()
)));
}
let root = if !self.events.is_empty() {
const EVENTS_AMT_BITWIDTH: u32 = 5;
let root = Amt::new_from_iter_with_bit_width(
DiscardBlockstore,
EVENTS_AMT_BITWIDTH,
self.events.iter(),
)
.context("failed to construct events AMT")
.or_fatal()?;
Some(root)
} else {
None
};
Ok(Events {
root,
events: self.events,
})
}
}