go-pulse/eth/downloader/modes.go
Marius van der Wijden d671dbd5b7
eth/downloader: fixes data race between synchronize and other methods (#21201)
* eth/downloaded: fixed datarace between synchronize and Progress

There was a race condition between `downloader.synchronize()` and `Progress` `syncWithPeer` `fetchHeight` `findAncestors` and `processHeaders`
This PR changes the behavior of the downloader a bit.
Previously the functions `Progress` `syncWithPeer` `fetchHeight` `findAncestors` and `processHeaders` read the syncMode anew within their loops. Now they read the syncMode at the start of their function and don't change it during their runtime.

* eth/downloaded: comment

* eth/downloader: added comment
2020-06-30 19:43:29 +02:00

75 lines
2.1 KiB
Go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package downloader
import "fmt"
// SyncMode represents the synchronisation mode of the downloader.
// It is a uint32 as it is used with atomic operations.
type SyncMode uint32
const (
FullSync SyncMode = iota // Synchronise the entire blockchain history from full blocks
FastSync // Quickly download the headers, full sync only at the chain head
LightSync // Download only the headers and terminate afterwards
)
func (mode SyncMode) IsValid() bool {
return mode >= FullSync && mode <= LightSync
}
// String implements the stringer interface.
func (mode SyncMode) String() string {
switch mode {
case FullSync:
return "full"
case FastSync:
return "fast"
case LightSync:
return "light"
default:
return "unknown"
}
}
func (mode SyncMode) MarshalText() ([]byte, error) {
switch mode {
case FullSync:
return []byte("full"), nil
case FastSync:
return []byte("fast"), nil
case LightSync:
return []byte("light"), nil
default:
return nil, fmt.Errorf("unknown sync mode %d", mode)
}
}
func (mode *SyncMode) UnmarshalText(text []byte) error {
switch string(text) {
case "full":
*mode = FullSync
case "fast":
*mode = FastSync
case "light":
*mode = LightSync
default:
return fmt.Errorf(`unknown sync mode %q, want "full", "fast" or "light"`, text)
}
return nil
}