go-ethereum/libevm/extraslock_test.go
Arran Schlosberg 1bccf4f2dd
refactor!: temporary extras require proof of global lock (#238)
## Why this should be merged

The `temporary.WithTempRegisteredExtras()` global lock introduced in
#234 wasn't fit for purpose when used in `coreth` as it required central
coordination of registration, types, and usage of the payload accessor.

## How this works

Instead of a central registration point, the new
`libevm.WithTemporaryExtrasLock()` function takes out a global lock and
provides the caller with a handle that proves the lock is held. All of
the override functions, e.g. `params.WithTempRegisteredExtras()` now
require a current lock, which will be propagated by the respective
`coreth` functions.

See https://github.com/ava-labs/coreth/pull/1328 for intended usage in
`coreth` and `subnet-evm`. A consumer of both of these can then safely
do the following:

```go
import (
    "github.com/ava-labs/libevm/libevm"

    coreth "github.com/ava-labs/coreth/plugin/evm"
    subnet "github.com/ava-labs/subnet-evm/plugin/evm"
)

// asCChain calls `fn` while emulating `coreth`. It is safe for concurrent usage with [asSubnetEVM].
func asCChain(fn func() error) error {
    return libevm.WithTemporaryExtrasLock(func(l libevm.ExtrasLock) error {
        return coreth.WithTempRegisteredLibEVMExtras(l, fn)
    })
}

// asSubnetEVM calls `fn` while emulating `subnet-evm`. It is safe for concurrent usage with [asCChain].
func asSubnetEVM(fn func() error) error {
    return libevm.WithTemporaryExtrasLock(func(l libevm.ExtrasLock) error {
        return subnet.WithTempRegisteredLibEVMExtras(l, fn)
    })
}
```

## How this was tested

Unit test of the new function plus existing integration tests of all
modified code.
2025-10-16 14:27:15 +00:00

52 lines
1.7 KiB
Go

// Copyright 2025 the libevm authors.
//
// The libevm additions to go-ethereum are free software: you can redistribute
// them and/or modify them 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 libevm additions are distributed in the hope that they 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 libevm_test
import (
"testing"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
// Testing from outside the package to guarantee usage of the public API only.
. "github.com/ava-labs/libevm/libevm"
)
func TestExtrasLock(t *testing.T) {
var zero ExtrasLock
assert.Panics(t, func() { _ = zero.Verify() }, "Verify() method of zero-value ExtrasLock{}")
testIntegration := func(t *testing.T) {
t.Helper()
require.NoError(t,
WithTemporaryExtrasLock((ExtrasLock).Verify),
"WithTemporaryExtrasLock((ExtrasLock).Verify)",
)
}
t.Run("initial_usage", testIntegration)
t.Run("lock_expiration", func(t *testing.T) {
var persisted ExtrasLock
require.NoError(t, WithTemporaryExtrasLock(func(l ExtrasLock) error {
persisted = l
return l.Verify()
}))
assert.ErrorIs(t, persisted.Verify(), ErrExpiredExtrasLock, "Verify() of persisted ExtrasLock")
})
t.Run("repeat_usage", testIntegration)
}