lotus/chain/vm/execution.go
2023-03-31 11:52:05 +02:00

174 lines
3.1 KiB
Go

package vm
import (
"context"
"errors"
"os"
"strconv"
"sync"
"github.com/ipfs/go-cid"
"github.com/filecoin-project/lotus/chain/types"
)
const (
DefaultAvailableExecutionLanes = 4
DefaultPriorityExecutionLanes = 2
)
var ErrExecutorDone = errors.New("executor has been released")
// the execution environment; see below for definition, methods, and initilization
var execution *executionEnv
// implementation of vm executor with simple sanity check preventing use after free.
type vmExecutor struct {
lk sync.RWMutex
vmi Interface
token *executionToken
done bool
}
var _ Executor = (*vmExecutor)(nil)
func newVMExecutor(vmi Interface, token *executionToken) Executor {
return &vmExecutor{vmi: vmi, token: token}
}
func (e *vmExecutor) ApplyMessage(ctx context.Context, cmsg types.ChainMsg) (*ApplyRet, error) {
e.lk.RLock()
defer e.lk.RUnlock()
if e.done {
return nil, ErrExecutorDone
}
return e.vmi.ApplyMessage(ctx, cmsg)
}
func (e *vmExecutor) ApplyImplicitMessage(ctx context.Context, msg *types.Message) (*ApplyRet, error) {
e.lk.RLock()
defer e.lk.RUnlock()
if e.done {
return nil, ErrExecutorDone
}
return e.vmi.ApplyImplicitMessage(ctx, msg)
}
func (e *vmExecutor) Flush(ctx context.Context) (cid.Cid, error) {
e.lk.RLock()
defer e.lk.RUnlock()
if e.done {
return cid.Undef, ErrExecutorDone
}
return e.vmi.Flush(ctx)
}
func (e *vmExecutor) Done() {
e.lk.Lock()
defer e.lk.Unlock()
e.token.Done()
e.token = nil
e.done = true
}
type executionToken struct {
reserved int
}
func (token *executionToken) Done() {
execution.putToken(token)
}
type executionEnv struct {
mx *sync.Mutex
cond *sync.Cond
// available executors
available int
// reserved executors
reserved int
}
func (e *executionEnv) getToken(lane ExecutionLane) *executionToken {
e.mx.Lock()
defer e.mx.Unlock()
switch lane {
case ExecutionLaneDefault:
for e.available <= e.reserved {
e.cond.Wait()
}
e.available--
return &executionToken{reserved: 0}
case ExecutionLanePriority:
for e.available == 0 {
e.cond.Wait()
}
e.available--
reserving := 0
if e.reserved > 0 {
e.reserved--
reserving = 1
}
return &executionToken{reserved: reserving}
default:
// already checked at interface boundary in NewVM, so this is appropriate
panic("bogus execution lane")
}
}
func (e *executionEnv) putToken(token *executionToken) {
e.mx.Lock()
defer e.mx.Unlock()
e.available++
e.reserved += token.reserved
e.cond.Broadcast()
}
func init() {
var available, priority int
var err error
concurrency := os.Getenv("LOTUS_FVM_CONCURRENCY")
if concurrency == "" {
available = DefaultAvailableExecutionLanes
}
available, err = strconv.Atoi(concurrency)
if err != nil {
panic(err)
}
reserved := os.Getenv("LOTUS_FVM_CONCURRENCY_RESERVED")
if reserved == "" {
priority = DefaultPriorityExecutionLanes
}
priority, err = strconv.Atoi(reserved)
if err != nil {
panic(err)
}
mx := &sync.Mutex{}
cond := sync.NewCond(mx)
execution = &executionEnv{
mx: mx,
cond: cond,
available: available,
reserved: priority,
}
}