英文:
Modify Golang internal file?
问题
你好！根据你的描述，你想通过修改go/src目录下的源文件来实现你的想法，但是遇到了错误。要解决这个问题，你可以按照以下步骤进行操作：
-
首先，确保你有足够的权限来修改
go/src目录下的文件。 -
在修改任何文件之前，建议先备份原始文件，以防止意外情况发生。
-
在你的
main.go文件中，将import sync改为import ./sync，这样可以确保导入的是你修改后的sync包。 -
将
go/src/sync文件夹复制到包含main.go文件的桌面文件夹中。 -
将
go/src/internal文件夹复制到包含main.go文件的桌面文件夹中。 -
修改
./sync文件夹中的所有文件，将引用internal/..的地方改为./internal/..。 -
运行
go run main.go命令，查看是否还有错误消息。
请注意，修改go/src目录下的源文件可能会导致不可预料的问题，建议在进行修改之前先备份文件，并谨慎操作。另外，修改标准库的源代码可能会导致与其他代码库的兼容性问题，需要谨慎考虑。
英文:
I had the idea of adding a sync.WaitGroup Limit(max int) function to resrict the number of the WaitGroup counter.
So I opened the waitgroup.go file in go/src/sync and made the changes, saved the file and tried testing it in a main.go file on my desktop. When I ran the file, it says:
$ go run main.go
wg.Limit undefined (type sync.WaitGroup has no field or method Limit)
To fix this error message, I copied the folder from go/src/sync into the folder on my desktop containing my main.go file and changed the import from sync to ./sync.
After running go run main.go this time, I got the following output:
$ go run main.go
sync\mutex.go:14:2: use of internal package not allowed
sync\pool.go:8:2: use of internal package not allowed
sync\rwmutex.go:8:2: use of internal package not allowed
sync\waitgroup.go:8:2: use of internal package not allowed
To fix these messages, I copied go/src/internal into the folder on my desktop containing my main.go file and I modified all the files in ./sync that reference internal/.. to ./internal/..
I run it again and I get the following output:
$ go run main.go
# _/C_/.../sync
sync\mutex.go:20: missing function body for "throw"
sync\pool.go:66: missing function body for "fastrand"
sync\pool.go:249: missing function body for "runtime_registerPoolCleanup"
sync\pool.go:250: missing function body for "runtime_procPin"
sync\pool.go:251: missing function body for "runtime_procUnpin"
sync\runtime.go:14: missing function body for "runtime_Semacquire"
sync\runtime.go:17: missing function body for "runtime_SemacquireMutex"
sync\runtime.go:23: missing function body for "runtime_Semrelease"
sync\runtime.go:36: missing function body for "runtime_notifyListAdd"
sync\runtime.go:39: missing function body for "runtime_notifyListWait"
sync\runtime.go:39: too many errors
How can I implement my simple idea by modifying the source files of go/src without receiving these errors?
答案1
得分: 0
在您安装的Go中，导航到src文件夹，并运行名为run.bat的文件，它将重新编译所有的包，从而消除您所描述的第一个错误。
英文:
In your installation of Go, navigate to the src folder and run the file called run.bat which will recompile all the packages removing the first error you described.
答案2
得分: 0
我真的不会通过更改标准库来实现这个，而是将WaitGroup封装起来，以便跟踪计数器，像这样：
type wg_limit struct {
wg sync.WaitGroup
current, max int
}
func (wgl *wg_limit) Add(delta int) error {
if wgl.current+delta > wgl.max {
return fmt.Errorf("计数器超过限制（当前：%d，最大：%d）", wgl.current, wgl.max)
}
wgl.current += delta
wgl.wg.Add(delta)
return nil
}
func (wgl *wg_limit) Done() {
wgl.current -= 1
wgl.wg.Done()
}
然后，使用一个max值初始化wg_limit，并像使用WaitGroup一样使用结果变量：
wgl := wg_limit{max: 3}
if err := wgl.Add(1); err != nil {
// 做一些操作()
// ...
wgl.Done()
}
如果Add(delta)的结果会导致WaitGroup计数器超过限制，将返回一个错误，并且WaitGroup不会改变。
英文:
I really wouldn't do this by changing the standard library, but instead wrap the WaitGroup to keep track of the counter like so:
type wg_limit struct {
wg sync.WaitGroup
current, max int
}
func (wgl *wg_limit) Add(delta int) error {
if wgl.current+delta > wgl.max {
return fmt.Errorf("counter exceeded (current: %d, max: %d)", wgl.current, wgl.max)
}
wgl.current += delta
wgl.wg.Add(delta)
return nil
}
func (wgl *wg_limit) Done() {
wgl.current -= 1
wgl.wg.Done()
}
Then init wg_limit with a value for max and use the resulting variable just like a WaitGroup:
wgl := wg_limit{max: 3}
if err := wgl.Add(1); err != nil {
// go something()
// ...
wgl.Done()
}
If the WaitGroup counter would be exceeded by the delta of Add(delta), an error is returned and the WaitGroup is unchanged.
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