Data race via graphql

[holiman]

Detected by travis cron-job (https://app.travis-ci.com/github/ethereum/go-ethereum/jobs/583768087)

==================
WARNING: DATA RACE
Write at 0x00c0006fe4a0 by goroutine 364:
  github.com/ethereum/go-ethereum/graphql.(*Transaction).Logs()
      /home/travis/gopath/src/github.com/ethereum/go-ethereum/graphql/graphql.go:466 +0x3b0
  runtime.call32()
      /home/travis/.gimme/versions/go1.19.1.linux.amd64/src/runtime/asm_amd64.s:725 +0x48
  reflect.Value.Call()
      /home/travis/.gimme/versions/go1.19.1.linux.amd64/src/reflect/value.go:368 +0xc7
  github.com/graph-gophers/graphql-go/internal/exec.execFieldSelection.func2()
      /home/travis/gopath/pkg/mod/github.com/graph-gophers/graphql-go@v1.3.0/internal/exec/exec.go:211 +0xa1b
  github.com/graph-gophers/graphql-go/internal/exec.execFieldSelection()
      /home/travis/gopath/pkg/mod/github.com/graph-gophers/graphql-go@v1.3.0/internal/exec/exec.go:231 +0x37d
  github.com/graph-gophers/graphql-go/internal/exec.(*Request).execSelections.func1()
      /home/travis/gopath/pkg/mod/github.com/graph-gophers/graphql-go@v1.3.0/internal/exec/exec.go:81 +0x2d4
  github.com/graph-gophers/graphql-go/internal/exec.(*Request).execSelections.func2()
      /home/travis/gopath/pkg/mod/github.com/graph-gophers/graphql-go@v1.3.0/internal/exec/exec.go:82 +0x47

Previous read at 0x00c0006fe4a0 by goroutine 365:
  github.com/ethereum/go-ethereum/rpc.(*BlockNumberOrHash).Hash()
      /home/travis/gopath/src/github.com/ethereum/go-ethereum/rpc/types.go:223 +0x144
  github.com/ethereum/go-ethereum/graphql.(*Transaction).Logs()
      /home/travis/gopath/src/github.com/ethereum/go-ethereum/graphql/graphql.go:460 +0xcb
  runtime.call32()
      /home/travis/.gimme/versions/go1.19.1.linux.amd64/src/runtime/asm_amd64.s:725 +0x48
  reflect.Value.Call()
      /home/travis/.gimme/versions/go1.19.1.linux.amd64/src/reflect/value.go:368 +0xc7
  github.com/graph-gophers/graphql-go/internal/exec.execFieldSelection.func2()
      /home/travis/gopath/pkg/mod/github.com/graph-gophers/graphql-go@v1.3.0/internal/exec/exec.go:211 +0xa1b
  github.com/graph-gophers/graphql-go/internal/exec.execFieldSelection()
      /home/travis/gopath/pkg/mod/github.com/graph-gophers/graphql-go@v1.3.0/internal/exec/exec.go:231 +0x37d
  github.com/graph-gophers/graphql-go/internal/exec.(*Request).execSelections.func1()
      /home/travis/gopath/pkg/mod/github.com/graph-gophers/graphql-go@v1.3.0/internal/exec/exec.go:81 +0x2d4
  github.com/graph-gophers/graphql-go/internal/exec.(*Request).execSelections.func2()
      /home/travis/gopath/pkg/mod/github.com/graph-gophers/graphql-go@v1.3.0/internal/exec/exec.go:82 +0x47
Goroutine 364 (running) created at:

func (t *Transaction) Logs(ctx context.Context) (*[]*Log, error) {
	if _, err := t.resolve(ctx); err != nil {
		return nil, err
	}
	if t.block == nil {
		return nil, nil
	}
	if _, ok := t.block.numberOrHash.Hash(); !ok {
		header, err := t.r.backend.HeaderByNumberOrHash(ctx, *t.block.numberOrHash)
		if err != nil {
			return nil, err
		}
		hash := header.Hash()
		t.block.numberOrHash.BlockHash = &hash             //  <--- THIS LINE
	}
	return t.getLogs(ctx)
}

func (bnh *BlockNumberOrHash) Hash() (common.Hash, bool) {
	if bnh.BlockHash != nil {                              //   <-- PREV READ
		return *bnh.BlockHash, true 
	}
	return common.Hash{}, false
}

[s1na]

This code keeps on giving...I'll look into it thanks for reporting.

[holiman]

t.block.numberOrHash.BlockHash = &hash 

Perhaps you can just change this to be set/read using atomic , via a setter and a getter?

[holiman]

Perhaps you can just change this to be set/read using atomic , via a setter and a getter?

Hm, the fields are public, so that's not a super-great change

[s1na]

Should be fixed as part of #26965.