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I made a HTTP server with Echo and store data use storm and data model like this:

project1(bucket)

 device_type_1(bucket)

  device_1(kv)

  device_2(kv)

 device_type_2(bucket)

  device_1(kv)

  device_2(kv)

project2(bucket)

 ...

In addition to updating the database, there are some other things to do after receive HTTP request, so I use transaction like this:

tx, err := db.Begin(true)
if err != nil {
  return
}
defer tx.Rollback()

// for simplicity
projectBkt := tx.From("project1")
projectBkt.Save(&project)


// other things
.......


if err := tx.Commit(); err != nil {
  return
}

A high probability of lock waiting while bolt transaction committing, and stack looks like this:

goroutine 53 [semacquire, 5 minutes]:
sync.runtime_SemacquireMutex(0xc000002560, 0x16a7f00, 0x0)
        C:/Go/src/runtime/sema.go:71 +0x4e
sync.(*RWMutex).Lock(0xc000002558)
        C:/Go/src/sync/rwmutex.go:103 +0xc0
go.etcd.io/bbolt.(*DB).mmap(0xc0000023c0, 0x20000, 0x0, 0x0)
        D:/data/Go/pkg/mod/go.etcd.io/bbolt@v1.3.0/db.go:246 +0x65
go.etcd.io/bbolt.(*DB).allocate(0xc0000023c0, 0x1, 0x0, 0x0, 0x0)
        D:/data/Go/pkg/mod/go.etcd.io/bbolt@v1.3.0/db.go:846 +0x24b
go.etcd.io/bbolt.(*Tx).allocate(0xc000e98fc0, 0x1, 0x0, 0x0, 0x0)
        D:/data/Go/pkg/mod/go.etcd.io/bbolt@v1.3.0/tx.go:454 +0x79
go.etcd.io/bbolt.(*node).spill(0xc0001539d0, 0x0, 0x0)
        D:/data/Go/pkg/mod/go.etcd.io/bbolt@v1.3.0/node.go:368 +0x3f0
go.etcd.io/bbolt.(*Bucket).spill(0xc0001cb740, 0x0, 0x0)
        D:/data/Go/pkg/mod/go.etcd.io/bbolt@v1.3.0/bucket.go:541 +0x73a
go.etcd.io/bbolt.(*Bucket).spill(0xc000e98fd8, 0x0, 0x0)
        D:/data/Go/pkg/mod/go.etcd.io/bbolt@v1.3.0/bucket.go:508 +0x64f
go.etcd.io/bbolt.(*Tx).Commit(0xc000e98fc0, 0x0, 0x0)
        D:/data/Go/pkg/mod/go.etcd.io/bbolt@v1.3.0/tx.go:163 +0x1bf
github.com/asdine/storm.(*node).Commit(0xc0001cb380, 0x0, 0x0)
        D:/data/Go/pkg/mod/github.com/asdine/storm@v2.1.2+incompatible/transaction.go:46 +0x5c
.....

The question is how can I detect the goroutine that occupies the lock so I can check the whole operation sequence?

4

1 回答 1

2

Goroutine 没有外部 ID。

通过设计，锁可以在一个 goroutine 中获取并在另一个 goroutine 中释放。因此，如果一个锁被持有，它不会被Goroutine 持有：任何人都可以解锁它，并且没有 ID 可以记录谁锁定了它。

（因此，答案是仅使用提供的互斥锁，您看不到谁在占用它。）

于 2019-10-16T01:59:03.073 回答