Read/write locking for javascript.... maybe? Stack overflow?

lock.js

var Lock = function() {
    this.readLocks = [];
    this.writeLocks = [];
}

Lock.prototype.getReadLock = function(callback) {
    var self = this;
    if (this.writeLocks.length > 0) {
        setTimeout(function() {self.getReadLock(callback);}, 5);
    } else {
        self.readLocks.push(true);
        var released = false;
        try {
            if (callback) {
                callback(function() {
                    self.readLocks.pop();
                    released = true;
                });
            }
        } catch (ex) {
            if (!released) {
                self.readLocks.pop();
            }
            throw ex;
        }
    }
}

Lock.prototype.getWriteLock = function(callback) {
    var self = this;
    var release = function() {
        self.writeLocks.shift();
    }
    if (self.writeLocks.length > 0) {
        setTimeout(function() {self.getWriteLock(callback);}, 10);
        return;
    }
    self.writeLocks.push(function() {callback(release);});
    var invokeWriteCallback = function() {
        if (self.readLocks.length == 0) {
            var cb = self.writeLocks[0];
            if (cb) {
                self.writeLocks[0] = null;
                cb();
            } else {
                setTimeout(invokeWriteCallback, 10);
            }
        } else {
            setTimeout(invokeWriteCallback, 10);
        }
    }
    invokeWriteCallback();

    
}