class Exceptionate

|type| must be a valid ZX_EXCEPTION_CHANNEL_TYPE_* constant.

Shuts the underlying channel down if it's still connected to be sure the

userspace endpoint gets the PEER_CLOSED signal.

In most cases the task wants to manually shutdown the exceptionate when

transitioning to a dead state, but in some cases tasks can be destroyed

without registering the dead state e.g. childless jobs.

Sets the backing ChannelDispatcher endpoint.

The exception channel is first-come-first-served, so if there is

already a valid channel in place (i.e. has a live peer) this will

fail.

The |*_rights| arguments give the rights to assign to task handles

provided through this exception channel. A value of 0 indicates that

the handle should not be made available through this channel.

Returns:

ZX_ERR_INVALID_ARGS if |channel| is null.

ZX_ERR_ALREADY_BOUND is there is already a valid channel.

ZX_ERR_BAD_STATE if Shutdown() has already been called.

Removes any exception channel, which will signal PEER_CLOSED for the

userspace endpoint.

Any further attempt to set a new channel will return ZX_ERR_BAD_STATE.

Returns true if the channel exists and has a valid userspace peer.

Sends an exception to userspace.

The exception message contains:

* 1 struct: zx_exception_info_t

* 1 handle: ExceptionDispatcher

Returns:

ZX_ERR_NEXT if there is no valid underlying channel.

ZX_ERR_NO_MEMORY if we failed to allocate memory.