Ruby ConditionVariable類用法及代碼示例

ConditionVariable 對象擴充類 Mutex 。使用條件變量，可以在臨界區中間暫停，直到資源可用。

例子：

mutex = Thread::Mutex.new
resource = Thread::ConditionVariable.new

a = Thread.new {
   mutex.synchronize {
     # Thread 'a' now needs the resource
     resource.wait(mutex)
     # 'a' can now have the resource
   }
}

b = Thread.new {
   mutex.synchronize {
     # Thread 'b' has finished using the resource
     resource.signal
   }
}