This function replaces task_suspend. When all callers are updated, zx_task_suspend() will be deleted and this function will be renamed zx_task_suspend().


Suspend the given task. Currently only thread or process handles may be suspended.


#include <zircon/syscalls.h>

zx_status_t zx_task_suspend_token(zx_handle_t handle, zx_handle_t* token);


zx_task_suspend_token() causes the requested task to suspend execution. Task suspension is not synchronous and the task might not be suspended before the call returns. The task will be suspended soon after zx_task_suspend_token() is invoked, unless it is currently blocked in the kernel, in which case it will suspend after being unblocked.

Invoking zx_task_kill() on a task that is suspended will successfully kill the task.


The allow the task to resume, close the suspend token handle. The task will remain suspended as long as there are any open suspend tokens. Like suspending, resuming is asynchronous so the thread may not be in a running state when the zx_handle_close() call returns, even if no other suspend tokens are open.


handle must be of type ZX_OBJ_TYPE_THREAD or ZX_OBJ_TYPE_PROCESS and have ZX_RIGHT_WRITE.

Return value

zx_task_suspend() returns ZX_OK on success. In the event of failure, a negative error value is returned.


ZX_ERR_BAD_HANDLE handle is not a valid handle.

ZX_ERR_WRONG_TYPE handle is not a thread handle.

ZX_ERR_INVALID_ARGS token was an invalid pointer.

ZX_ERR_BAD_STATE The task is not in a state where suspending is possible.


Currently only thread handles are supported.