lock.ts

namespace web {

    let global = sync.newMutex();
    let locks: Map<sync.Mutex> = <any>{}

    export function getLockedMutex(key: string): sync.Mutex {
        global.lock()
        try {
            let m = locks[key]
            if (!m) {
                m = sync.newMutex()
                locks[key] = m;
            }
            // lock the mutex inside the global lock
            m.lock();
            return m;
        }
        finally {
            global.unlock()
        }
    }
}