binder的rpc到底是同步还是异步的？

[hippyk]

本文当中说是单向异步的，但是这篇文章里面却说是同步的，求真相

[hippyk]

貌似确实是同步的，官方文档：For example, when an IPC is made from process A to process B, the calling thread in A blocks in transact() as it sends the transaction to process B. The next available pool thread in B receives the incoming transaction, calls Binder.onTransact() on the target object, and replies with the result Parcel. Upon receiving its result, the thread in process A returns to allow its execution to continue.

https://developer.android.com/reference/android/os/IBinder.html

[xuning2516]

支持异步binder，onTransact指定FLAG_ONEWAY，就是异步调用。