Example of deadlocking the Trillian memory storage backend with a uninitialized log

main.go

package main

import (
	"context"
	"fmt"
	"github.com/google/trillian/util/clock"

	"github.com/google/trillian"
	"github.com/google/trillian/server"
	"github.com/google/trillian/storage"
	"github.com/google/trillian/extension"
	"github.com/google/trillian/merkle/rfc6962"
	stestonly "github.com/google/trillian/storage/testonly"
)


func main() {
	th := rfc6962.DefaultHasher
	var tree *trillian.Tree
	ctx := context.Background()
	sp, _ := server.NewStorageProvider("memory", nil)
	sp.AdminStorage().ReadWriteTransaction(ctx, func(ctx context.Context, tx storage.AdminTX) error {
		tree, _ = tx.CreateTree(ctx, stestonly.LogTree)
		tx.Commit()
		return nil
	})
	registry := extension.Registry{
		AdminStorage: sp.AdminStorage(),
		LogStorage:   sp.LogStorage(),
	}
	timeSource := clock.System
	logServer := *server.NewTrillianLogRPCServer(registry, timeSource)
	data := []byte(`foo`)
	hash, _:= th.HashLeaf(data)
	leaf := &trillian.LogLeaf{
		MerkleLeafHash:   hash,
		LeafValue:        data,
		LeafIdentityHash: hash,
	}
	req := &trillian.QueueLeavesRequest{LogId: tree.TreeId, Leaves: []*trillian.LogLeaf{leaf}}
	logServer.QueueLeaves(ctx, req) // tx isn't closed
	logServer.QueueLeaves(ctx, req) // blocks on acquiring lock
	fmt.Print("Deadlocked?")
}