mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-12-25 19:28:57 +01:00
58366ce64d
If multiple Ebiten processes start at the same time, the file operation can cause a race condition. Add a file lock to avoid this.
88 lines
2.0 KiB
Go
88 lines
2.0 KiB
Go
// Copyright 2021 The Ebiten Authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
//go:build !ebitenexternaldll
|
|
// +build !ebitenexternaldll
|
|
|
|
package glfw
|
|
|
|
import (
|
|
"bytes"
|
|
"compress/gzip"
|
|
"io"
|
|
"os"
|
|
"path/filepath"
|
|
|
|
"github.com/gofrs/flock"
|
|
"golang.org/x/sys/windows"
|
|
)
|
|
|
|
func writeDLLFile(name string) error {
|
|
f, err := gzip.NewReader(bytes.NewReader(glfwDLLCompressed))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer f.Close()
|
|
|
|
out, err := os.Create(name)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer out.Close()
|
|
|
|
if _, err := io.Copy(out, f); err != nil {
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func loadDLL() (*dll, error) {
|
|
cachedir, err := os.UserCacheDir()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
dir := filepath.Join(cachedir, "ebiten")
|
|
if err := os.MkdirAll(dir, 0755); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Make the file operation atomic among multiple processes.
|
|
fl := flock.New(filepath.Join(dir, glfwDLLHash+".lock"))
|
|
fl.Lock()
|
|
defer fl.Unlock()
|
|
|
|
fn := filepath.Join(dir, glfwDLLHash+".dll")
|
|
if _, err := os.Stat(fn); err != nil {
|
|
if !os.IsNotExist(err) {
|
|
return nil, err
|
|
}
|
|
|
|
// Create a DLL as a temporary file and then rename it later.
|
|
// Without the temporary file, writing a DLL might fail in the process of writing and Ebiten cannot
|
|
// notice that the DLL file is incomplete.
|
|
if err := writeDLLFile(fn + ".tmp"); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if err := os.Rename(fn+".tmp", fn); err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
|
|
return &dll{
|
|
d: windows.NewLazyDLL(fn),
|
|
}, nil
|
|
}
|