waitq.h File Reference

#include <ds/list.h>

Go to the source code of this file.

Data Structures
struct	waitq

Functions
int	waitq_sleep (struct waitq *waitq)
	Puts the current thread to sleep on a wait queue until it is woken up.
void	waitq_sleep_unint (struct waitq *waitq)
	Puts the current thread to sleep on a wait queue until it is woken up, whatever signals come meanwhile.
void	waitq_wakeup (struct waitq *waitq)
	Wakes up every thread sleeping on a wait queue, and every thread polling it.
void	waitq_wakeup_nopoll (struct waitq *waitq)
	Wakes up every thread sleeping on a wait queue, but not the threads polling it.
void	thread_wakeup (struct thread *thread)
	Wakes up one thread, if it is sleeping on a wait queue.
int	poll_register (struct waitq *waitq)
	Registers a wait queue that the current thread, in select() or poll(), waits for: a wakeup of that queue also wakes the thread.
void	poll_unregister (struct thread *thread)
	Removes every registration of a thread, when it stops waiting (it was woken up, or it is going away).

Function Documentation

poll_register()

int poll_register

(

struct waitq *

queue

)

Registers a wait queue that the current thread, in select() or poll(), waits for: a wakeup of that queue also wakes the thread.

Registering the same queue twice does nothing.

Parameters

queue

the wait queue, or NULL to be woken by any wakeup

Returns

0, or -ENOMEM if there was no memory for the registration

Definition at line 112 of file waitq.c.

References curthread, kmalloc(), poll_reg::next, poll_chain(), poll_register(), poll_regs, thread::poll_regs, poll_reg::queue, poll_reg::thread, and poll_reg::thread_next.

Referenced by fd_watch(), and poll_register().

poll_unregister()

void poll_unregister

(

struct thread *

thread

)

Removes every registration of a thread, when it stops waiting (it was woken up, or it is going away).

Parameters

thread

the thread whose registrations go

Definition at line 144 of file waitq.c.

References kfree(), poll_reg::next, poll_chain(), poll_regs, thread::poll_regs, poll_unregister(), poll_reg::queue, and poll_reg::thread_next.

Referenced by poll_unregister(), sys_poll(), sys_select(), and thread_kill().

thread_wakeup()

void thread_wakeup

(

struct thread *

thread

)

Wakes up one thread, if it is sleeping on a wait queue.

The other threads on that queue keep sleeping.

Parameters

thread

the thread to wake up

Definition at line 216 of file waitq.c.

References NULL, thread::run_link, sched_thread_wake(), thread_wakeup(), and thread::waitq.

Referenced by net_callout_set(), rx_queue(), sched_timer_tick(), signal_to(), and thread_wakeup().

waitq_sleep()

int waitq_sleep

(

struct waitq *

waitq

)

Puts the current thread to sleep on a wait queue until it is woken up.

A signal that the process doesn't block also ends the sleep (signal_to() wakes the thread). The system call should then return, so that the signal can be delivered. If a signal is already pending, the thread doesn't sleep at all.

A wakeup only means that something changed, so callers sleep in a loop and look again at what they wait for each time.

Parameters

waitq

the wait queue to sleep on

Returns

0 once woken up, or -ERESTARTSYS if a signal ended the sleep

Definition at line 50 of file waitq.c.

References curthread, ERESTARTSYS, ISLEEP, signal_interrupts(), sleep_on(), and waitq_sleep().

Referenced by pipefs_fifo_open(), posix_file_write(), pty_master_write(), pty_slave_write(), sched_wait(), socket_unix_accept(), socket_unix_connect(), socket_unix_recv(), socket_unix_send(), sys_sigsuspend(), sys_thread_join(), sys_waitpid(), tty_wait_start(), vfs_file_flock(), vt_kd_ioctl(), and waitq_sleep().

waitq_sleep_unint()

void waitq_sleep_unint

(

struct waitq *

waitq

)

Puts the current thread to sleep on a wait queue until it is woken up, whatever signals come meanwhile.

This is for waits that can't be abandoned halfway, such as a disk transfer or a page being read in.

Parameters

waitq

the wait queue to sleep on

Definition at line 67 of file waitq.c.

References sleep_on(), USLEEP, and waitq_sleep_unint().

Referenced by channel_acquire(), dma_transfer(), proc_threads_exec(), signal_stop(), and waitq_sleep_unint().

waitq_wakeup()

void waitq_wakeup

(

struct waitq *

waitq

)

Wakes up every thread sleeping on a wait queue, and every thread polling it.

The threads become ready to run.

Parameters

waitq

the wait queue (NULL does nothing)

Definition at line 178 of file waitq.c.

References poll_regs, poll_wake(), waitq_wakeup(), and waitq_wakeup_nopoll().

Referenced by inet_sock_deliver(), inet_sock_error(), lock_unlock(), pipefs_close(), pipefs_fifo_open(), posix_file_read(), posix_file_write(), proc_zombie_notify(), ps2mouse_handler(), ptm_read(), pts_read(), pty_free(), sched_thread_killed(), signal_notify_parent(), signal_to(), socket_inet_shut(), socket_unix_accept(), socket_unix_connect(), socket_unix_recv(), socket_unix_send(), socket_unix_shutdown(), sys_thread_exit(), tcp_wakeup(), tty_free(), tty_ioctl(), tty_master_write(), uart_receive_handler(), uart_transmit_handler(), unix_conn_wakeup(), vfs_file_flock(), vt_input_to(), vt_switch_now(), and waitq_wakeup().

waitq_wakeup_nopoll()

void waitq_wakeup_nopoll

(

struct waitq *

waitq

)

Wakes up every thread sleeping on a wait queue, but not the threads polling it.

This is for queues that no file descriptor waits through, such as a disk request's, and for the pollers' own queues.

Parameters

waitq

the wait queue (NULL does nothing)

Definition at line 196 of file waitq.c.

References list_entry, NULL, thread::run_link, sched_thread_wake(), waitq::threads, thread::waitq, and waitq_wakeup_nopoll().

Referenced by channel_release(), dma_irq(), poll_wake(), waitq_wakeup(), and waitq_wakeup_nopoll().