Concurrent INSERT statements hanging

[tpickett66]

What version of Chai are you using?

v0.16.0

What did you do?

I'm trying to build up a listing of similar data from several sources concurrently. When I got everything wired up I noticed my program wasn't making progress; after much debugging I realized things were hanging at db.Exec() while trying to insert into the database. The runtime isn't reporting a deadlock.

Below is an example that reproduces the behavior I'm seeing.

package main

import (
	"fmt"
	"os"
	"sync"

	"github.com/chaisql/chai"
)

const iterations int = 10
const concurrency int = 2

func main() {
	db, err := chai.Open(":memory:")
	if err != nil {
		panic(err)
	}
	err = db.Exec("CREATE TABLE vals (id text not null)")
	if err != nil {
		panic(err)
	}

	var wg sync.WaitGroup
	for i := 1; i <= concurrency; i++ {
		worker := i
		wg.Add(1)
		go func() {
			defer wg.Done()
			insertThings(worker, db)
		}()
	}

	wg.Wait()
}

func insertThings(workerNum int, db *chai.DB) {
	for j := 1; j < iterations; j++ {
		val := fmt.Sprintf("%d-%d", workerNum, j)
		fmt.Fprintf(os.Stdout, "Inserting %s.\n", val)

		err := db.Exec("INSERT INTO vals (id) VALUES (?)", val)
		if err != nil {
			panic(err)
		}
		fmt.Fprintf(os.Stdout, "inserted.\n", val)
	}
}

What did you expect to see?

I expected to see about 40 lines of output with each "worker" announcing an insert then success for the numbers 1-10.

What did you see instead?

I get 2-4 lines of output then an indefinite pause.

Example Output:

$ go run main.go
Inserting 2-1.
Inserting 1-1.

[tpickett66]

I just tried again using the latest commit and a separate Connection for each worker, same result.

[kksh3ll]

Is anybody here ，hello，hello ~~~