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Improve VM executor stack size estimation rules (#8439)

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* Improve VM executor stack size estimation rules

* typo: docs add "(Debug build)" comment

* Fix an off by one typo and set minimal stack size

This avoids the case if `depth_threshold == max_depth`. Usually setting stack size to zero will just rebound it to
platform minimal stack size, but we set it here just in case.

* Use saturating_sub to avoid potential overflow
This commit is contained in:
Wei Tang 2018-04-20 18:32:25 +08:00 committed by Afri Schoedon
parent 24f6d8296b
commit 28b5906d9e
1 changed files with 21 additions and 12 deletions
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33
ethcore/src/executive.rs
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@ -34,10 +34,21 @@ use transaction::{Action, SignedTransaction};
use crossbeam;
pub use executed::{Executed, ExecutionResult};
/// Roughly estimate what stack size each level of evm depth will use
/// TODO [todr] We probably need some more sophisticated calculations here (limit on my machine 132)
/// Maybe something like here: `https://github.com/ethereum/libethereum/blob/4db169b8504f2b87f7d5a481819cfb959fc65f6c/libethereum/ExtVM.cpp`
const STACK_SIZE_PER_DEPTH: usize = 24*1024;
#[cfg(debug_assertions)]
/// Roughly estimate what stack size each level of evm depth will use. (Debug build)
const STACK_SIZE_PER_DEPTH: usize = 128 * 1024;
#[cfg(not(debug_assertions))]
/// Roughly estimate what stack size each level of evm depth will use.
const STACK_SIZE_PER_DEPTH: usize = 24 * 1024;
#[cfg(debug_assertions)]
/// Entry stack overhead prior to execution. (Debug build)
const STACK_SIZE_ENTRY_OVERHEAD: usize = 100 * 1024;
#[cfg(not(debug_assertions))]
/// Entry stack overhead prior to execution.
const STACK_SIZE_ENTRY_OVERHEAD: usize = 20 * 1024;
/// Returns new address created from address, nonce, and code hash
pub fn contract_address(address_scheme: CreateContractAddress, sender: &Address, nonce: &U256, code: &[u8]) -> (Address, Option<H256>) {
@ -332,12 +343,12 @@ impl<'a, B: 'a + StateBackend> Executive<'a, B> {
tracer: &mut T,
vm_tracer: &mut V
) -> vm::Result<FinalizationResult> where T: Tracer, V: VMTracer {
let depth_threshold = ::io::LOCAL_STACK_SIZE.with(|sz| sz.get() / STACK_SIZE_PER_DEPTH);
let local_stack_size = ::io::LOCAL_STACK_SIZE.with(|sz| sz.get());
let depth_threshold = local_stack_size.saturating_sub(STACK_SIZE_ENTRY_OVERHEAD) / STACK_SIZE_PER_DEPTH;
let static_call = params.call_type == CallType::StaticCall;
// Ordinary execution - keep VM in same thread
if (self.depth + 1) % depth_threshold != 0 {
if self.depth != depth_threshold {
let vm_factory = self.state.vm_factory();
let mut ext = self.as_externalities(OriginInfo::from(&params), unconfirmed_substate, output_policy, tracer, vm_tracer, static_call);
trace!(target: "executive", "ext.schedule.have_delegate_call: {}", ext.schedule().have_delegate_call);
@ -345,17 +356,15 @@ impl<'a, B: 'a + StateBackend> Executive<'a, B> {
return vm.exec(params, &mut ext).finalize(ext);
}
// Start in new thread to reset stack
// TODO [todr] No thread builder yet, so we need to reset once for a while
// https://github.com/aturon/crossbeam/issues/16
// Start in new thread with stack size needed up to max depth
crossbeam::scope(|scope| {
let vm_factory = self.state.vm_factory();
let mut ext = self.as_externalities(OriginInfo::from(&params), unconfirmed_substate, output_policy, tracer, vm_tracer, static_call);
scope.spawn(move || {
scope.builder().stack_size(::std::cmp::max(schedule.max_depth.saturating_sub(depth_threshold) * STACK_SIZE_PER_DEPTH, local_stack_size)).spawn(move || {
let mut vm = vm_factory.create(&params, &schedule);
vm.exec(params, &mut ext).finalize(ext)
})
}).expect("Sub-thread creation cannot fail; the host might run out of resources; qed")
}).join()
}