type User struct {
ID uint64
Balance uint64
Lock sync.Mutex
}
func transfer(from *User, to *User, amount uint64) {
from.Lock.Lock()
to.Lock.Lock()
defer from.Lock.Unlock()
defer to.Lock.Unlock()
if from.Balance >= amount {
from.Balance -= amount
to.Balance += amount
}
}
func main() {
userA := User{
ID: 1, Balance: 10e10,
}
userB := User{
ID: 2, Balance: 10e10,
}
wg := sync.WaitGroup{}
wg.Add(2)
go func() {
defer wg.Done()
for _ = range [10e10]uint64{} {
transfer(&userA, &userB, 1)
}
}()
go func() {
defer wg.Done()
for _ = range [10e10]uint64{} {
transfer(&userB, &userA, 1)
}
}()
wg.Wait()
}
or
or
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