pub fn block_current_task()Expand description
Block the current task and yield to the scheduler.
The current task is moved from Running to Blocked state and placed
in the blocked_tasks map. It will not be re-scheduled until
wake_task(id) is called.
§Lock design
This function acquires only the BLOCKED_TASKS lock + the current
CPU’s LOCAL_SCHEDULERS[cpu] lock. It does not touch
GLOBAL_SCHED_STATE, avoiding contention with cold-path operations
(fork, exit, kill).
§Lost-wakeup prevention
Before actually blocking, this function checks the task’s wake_pending
flag. If a concurrent wake_task() fired between the moment the task
added itself to a WaitQueue and this call, the flag will be set and
the function returns immediately without blocking.
Must NOT be called with interrupts disabled or while holding the scheduler lock (this function acquires both).