WaitOn

Waits until h has something to report, or timeout milliseconds pass.

Number	Selector	Blocking	Since
0x07 SVC_WAITON	—	yes	2.0

SvcResult WaitOn(Handle h, Duration timeout);

Registers: (h, timeout) -> r0 status, r1-r3 per handle type

The generic wait for ports, events, tasks and spaces; it returns as soon as something arrives. What r1-r3 carry depends on the handle type:

Handle	r1	r2	r3
Port	sender's marker	message length	granted handle, or -1
Event	signalled bits (now cleared)
Task	exit status or fault reason		TASK_EXITED or TASK_FAULTED
Space	last task's exit status

Receiving on a port leaves the caller holding the call: it must Reply() or Hold() before receiving again. Waiting on a task that has already exited or faulted returns at once with ZUZU_OK. WaitOnPort(), WaitOnEvent(), WaitOnTask() and WaitOnSpace() unpack the result into typed structs.

Parameters

Name	Direction	Description
h	in	Port, event, task or space handle with PERM_WAIT.
timeout	in	Milliseconds to wait; TIMEOUT_POLL checks and returns at once, TIMEOUT_INFINITE waits forever.

Returns

r0 is the status; r1-r3 as in the table above.

Errors

Error	Condition
ERR_TIMEOUT	Nothing arrived within timeout (or nothing was there, for a poll).
ERR_BADHANDLE	h is not a live handle.
ERR_NOPERM	h lacks PERM_WAIT.
ERR_BADTYPE	h is not a port, event, task or space.
ERR_DEAD	The port or event was destroyed, or the space was torn down.
ERR_BUSY	Port only: the caller still holds an unanswered call.
ERR_BADARG	h is the caller's own task or own space.