This library provides the scaffolding for creating fake userspace versions of kernel objects for testing. A fake handle table is maintained by the library, and a fake Object base class is provided to build derived object types. It is mostly useful if your goal is to test interfaces that must go through syscalls or pretend to interact with hardware that cannot be mocked or faked easily. Bus drivers and platform level authentication & token mechanisms like Resources, BTIs, and the like are the target audience. At this time the library only supports single process tests, and each statically linked binary will have its own fake handle table.

The library provides strong symbols for the following syscalls so that they can be dispatched to virtual methods within the implemented Object:

• zx_object_get_child()
• zx_object_get_info()
• zx_object_get_property()
• zx_object_set_profile()
• zx_object_set_property()
• zx_object_signal()
• zx_object_signal_peer()
• zx_object_wait_one()
• zx_object_wait_async()

In addition, the following handle-related syscalls are provided to manipulate fake handles vended by the library:

• zx_handle_duplicate()
• zx_handle_replace()
• zx_handle_close()
• zx_handle_close_many()

The library provides zx_object_wait_many() but its purpose is to catch errant calls to it that contain a fake handle in the zx_wait_item_t list. Waiting on multiple handles with one or more fake handles in the mix is not supported.