OS API provides the basic function for application to interact with underlying resource managed by OS, such as disk file, memory GUI,network, event, OS object, thread.
You can use these API to construct your own framework or application.
In Reactor socket programming, the OS provide you Synchronization API to create socket, bind port, connect to remote, read and write socket and direct memory buffer.
Meanwhile the OS also offer the addition indirections that can notify you something you intreasted happened when hardware create interrupts and OS competed handling
interrupts. Take socket as example, we can create socket ans selector with OS API, and then use OS API to register some intrested events of the socket to selector.
Now some of Synchronization operation can be handled as Asynchronous operation.
When the you call OS API to do something, you just call it in unblocked way, at the same time you registed the event to related handle.
If the OS completes the task that you, the OS will check if the related handle exist, and created connection between event and handle.
and you continually check if there is event related the handle in another thread. If event exist, we handle it, or just put it on queue to notify other thread to handle.
1. Reactor Model
2. Event-Driven
3. Thread Model
