KOS Native Kernel Threading API More...

Files
file	cond.h
	Condition variables.

file	genwait.h
	Generic wait system.

file	mutex.h
	Mutual exclusion locks.

file	once.h
	Dynamic package initialization.

file	oneshot_timer.h
	One-shot timer support.

file	recursive_lock.h
	Definitions for a recursive mutex.

file	rwsem.h
	Definition for a reader/writer semaphore.

file	sem.h
	Semaphores.

file	thread.h
	Threading support.

file	tls.h
	Thread-local storage support.

file	worker_thread.h
	Threaded worker support.

file	spinlock.h
	Simple locking.

Data Structures
struct	tcbhead_t
	Thread Control Block Header. More...

struct	kthread_t
	Structure describing one running thread. More...

struct	kthread_attr_t
	Thread creation attributes. More...

Macros
#define	KOS_PID 1
	Process ID.

#define	PRIO_MAX 4096
	Maximal thread priority.

#define	PRIO_DEFAULT 10
	Default thread priority.

#define	KTHREAD_LABEL_SIZE 256
	Size of a kthread's label.

#define	KTHREAD_PWD_SIZE 256
	Size of a kthread's current directory.

Typedefs
typedef uint8_t	kthread_flags_t
	Kernel thread flags type.

Enumerations
enum	kthread_state_t { STATE_ZOMBIE = 0x0000 , STATE_RUNNING = 0x0001 , STATE_READY = 0x0002 , STATE_WAIT = 0x0003 , STATE_FINISHED = 0x0004 }
	Kernel thread state. More...

enum	kthread_mode_t { THD_MODE_NONE = -1 , THD_MODE_COOP = 0 , THD_MODE_PREEMPT = 1 }
	kthread mode values More...

Functions
int	thd_block_now (irq_context_t *mycxt)
	Block the current thread.

irq_context_t *	thd_choose_new (void)
	Find a new thread to swap in.

kthread_t *	thd_by_tid (tid_t tid)
	Given a thread ID, locates the thread structure.

void	thd_add_to_runnable (kthread_t *t, bool front_of_line)
	Enqueue a process in the runnable queue.

int	thd_remove_from_runnable (kthread_t *thd)
	Removes a thread from the runnable queue, if it's there.

kthread_t *	thd_create (bool detach, void (routine)(void param), void param)
	Create a new thread.

kthread_t *	thd_create_ex (const kthread_attr_t __RESTRICT attr, void (routine)(void param), void *param)
	Create a new thread with the specified set of attributes.

int	thd_destroy (kthread_t *thd)
	Brutally kill the given thread.

void	thd_exit (void *rv) __noreturn
	Exit the current thread.

void	thd_schedule (bool front_of_line, uint64_t now)
	Force a thread reschedule.

void	thd_schedule_next (kthread_t *thd)
	Force a given thread to the front of the queue.

void	thd_pass (void)
	Throw away the current thread's timeslice.

void	thd_sleep (unsigned ms)
	Sleep for a given number of milliseconds.

int	thd_set_prio (kthread_t *thd, prio_t prio)
	Set a thread's priority value.

kthread_t *	thd_get_current (void)
	Retrieve the current thread's kthread struct.

const char *	thd_get_label (kthread_t *thd)
	Retrieve the thread's label.

void	thd_set_label (kthread_t thd, const char __RESTRICT label)
	Set the thread's label.

const char *	thd_get_pwd (kthread_t *thd)
	Retrieve the thread's current working directory.

void	thd_set_pwd (kthread_t thd, const char __RESTRICT pwd)
	Set the thread's current working directory.

int *	thd_get_errno (kthread_t *thd)
	Retrieve a pointer to the thread errno.

struct _reent *	thd_get_reent (kthread_t *thd)
	Retrieve a pointer to the thread reent struct.

uint64_t	thd_get_cpu_time (kthread_t *thd)
	Retrieves the thread's elapsed CPU time.

int	thd_set_mode (kthread_mode_t mode) __deprecated
	Change threading modes.

kthread_mode_t	thd_get_mode (void) __deprecated
	Fetch the current threading mode.

int	thd_set_hz (unsigned int hertz)
	Set the scheduler's frequency.

unsigned	thd_get_hz (void)
	Fetch the scheduler's current frequency.

int	thd_join (kthread_t thd, void *value_ptr)
	Wait for a thread to exit.

int	thd_detach (kthread_t *thd)
	Detach a joinable thread.

int	thd_each (int(cb)(kthread_t thd, void user_data), void data)
	Iterate all threads and call the passed callback for each.

int	thd_pslist (int(pf)(const char fmt,...))
	Print a list of all threads using the given print function.

int	thd_pslist_queue (int(pf)(const char fmt,...))
	Print a list of all queued threads using the given print function.

kthread_t *	thd_by_tid (tid_t tid)
	Given a thread ID, locates the thread structure.

void	thd_add_to_runnable (kthread_t *t, bool front_of_line)
	Enqueue a process in the runnable queue.

int	thd_remove_from_runnable (kthread_t *thd)
	Removes a thread from the runnable queue, if it's there.

kthread_t *	thd_create (bool detach, void (routine)(void param), void param)
	Create a new thread.

kthread_t *	thd_create_ex (const kthread_attr_t __RESTRICT attr, void (routine)(void param), void *param)
	Create a new thread with the specified set of attributes.

int	thd_destroy (kthread_t *thd)
	Brutally kill the given thread.

void	thd_schedule_next (kthread_t *thd)
	Force a given thread to the front of the queue.

int	thd_set_prio (kthread_t *thd, prio_t prio)
	Set a thread's priority value.

kthread_t *	thd_get_current (void)
	Retrieve the current thread's kthread struct.

const char *	thd_get_label (kthread_t *thd)
	Retrieve the thread's label.

void	thd_set_label (kthread_t thd, const char __RESTRICT label)
	Set the thread's label.

const char *	thd_get_pwd (kthread_t *thd)
	Retrieve the thread's current working directory.

void	thd_set_pwd (kthread_t thd, const char __RESTRICT pwd)
	Set the thread's current working directory.

int *	thd_get_errno (kthread_t *thd)
	Retrieve a pointer to the thread errno.

struct _reent *	thd_get_reent (kthread_t *thd)
	Retrieve a pointer to the thread reent struct.

uint64_t	thd_get_cpu_time (kthread_t *thd)
	Retrieves the thread's elapsed CPU time.

int	thd_join (kthread_t thd, void *value_ptr)
	Wait for a thread to exit.

int	thd_detach (kthread_t *thd)
	Detach a joinable thread.

int	thd_each (int(cb)(kthread_t thd, void user_data), void data)
	Iterate all threads and call the passed callback for each.

Thread flag values
Flags for kthread_flags_t These are possible values for the flags field on the kthread_t structure. These can be ORed together.
#define	THD_DEFAULTS 0
	Defaults: no flags.

#define	THD_USER 1
	Thread runs in user mode.

#define	THD_QUEUED 2
	Thread is in the run queue.

#define	THD_DETACHED 4
	Thread is detached.

#define	THD_OWNS_STACK 8
	Thread manages stack lifetime.

Detailed Description

KOS Native Kernel Threading API

The thread scheduler itself is a relatively simplistic priority scheduler. There is no provision for priorities to erode over time, so keep that in mind. That practically means that if you have 2 high priority threads that are always runnable and one low priority thread that is always runnable, the low priority thread will never actually run (since it will never get to the front of the run queue because of the high priority threads).

The scheduler supports two distinct types of threads: joinable and detached threads. A joinable thread is one that can return a value to the creating thread (or for that matter, any other thread that wishes to join it). A detached thread is one that is completely detached from the rest of the system and cannot return values by "normal" means. Detached threads automatically clean up all of the internal resources associated with the thread when it exits. Joinable threads, on the other hand, must keep some state available for the ability to return values. To make sure that all memory allocated by the thread's internal structures gets freed, you must either join with the thread (with thd_join()) or detach it (with thd_detach()). The old KOS threading system only had what would be considered detached threads.

See also: semaphore_t, mutex_t, kthread_once_t, kthread_key_t, rw_semaphore_t

Macro Definition Documentation

◆ KOS_PID

#define KOS_PID 1

Process ID.

This macro defines the single process ID that encompasses all of KOS and the running application along with all of its threads.

◆ KTHREAD_LABEL_SIZE

#define KTHREAD_LABEL_SIZE 256

Size of a kthread's label.

Maximum number of characters in a thread's label or name (including NULL terminator).

◆ KTHREAD_PWD_SIZE

#define KTHREAD_PWD_SIZE 256

Size of a kthread's current directory.

Maximum number of characters in a thread's current working directory (including NULL terminator).

◆ PRIO_DEFAULT

#define PRIO_DEFAULT 10

Default thread priority.

Threads are created by default with the priority specified.

◆ PRIO_MAX

#define PRIO_MAX 4096

Maximal thread priority.

This macro defines the maximum value for a thread's priority. Note that the larger this number, the lower the priority of the thread.

◆ THD_DEFAULTS

#define THD_DEFAULTS 0

Defaults: no flags.

◆ THD_DETACHED

#define THD_DETACHED 4

Thread is detached.

◆ THD_OWNS_STACK

#define THD_OWNS_STACK 8

Thread manages stack lifetime.

◆ THD_QUEUED

#define THD_QUEUED 2

Thread is in the run queue.

◆ THD_USER

#define THD_USER 1

Thread runs in user mode.

Typedef Documentation

◆ kthread_flags_t

typedef uint8_t kthread_flags_t

Kernel thread flags type.

Enumeration Type Documentation

◆ kthread_mode_t

enum kthread_mode_t

kthread mode values

Deprecated: Only preemptive scheduling is still supported!

The threading system will always be in one of the following modes. This represents either pre-emptive scheduling or an un-initialized state.

Enumerator

THD_MODE_NONE

Threads not running.

THD_MODE_COOP

Cooperative mode.

Deprecated

THD_MODE_PREEMPT

Preemptive threading mode.

◆ kthread_state_t

enum kthread_state_t

Kernel thread state.

Each thread in the system is in exactly one of this set of states.

Enumerator
STATE_ZOMBIE	Waiting to die.
STATE_RUNNING	Process is "current".
STATE_READY	Ready to be scheduled.
STATE_WAIT	Blocked on a genwait.
STATE_FINISHED	Finished execution.

Function Documentation

◆ thd_add_to_runnable() [1/2]

void thd_add_to_runnable	(	kthread_t *	t,
		bool	front_of_line )

This function adds a thread to the runnable queue after the process group of the same priority if front_of_line is zero, otherwise queues it at the front of its priority group. Generally, you will not have to do this manually.

Parameters

t	The thread to queue.
front_of_line	Set to true to put this thread in front of other threads of the same priority, false to put it behind the other threads (normal behavior).

See also: thd_remove_from_runnable

◆ thd_add_to_runnable() [2/2]

void thd_add_to_runnable	(	kthread_t *	t,
		bool	front_of_line )

Enqueue a process in the runnable queue.

This function adds a thread to the runnable queue after the process group of the same priority if front_of_line is zero, otherwise queues it at the front of its priority group. Generally, you will not have to do this manually.

Parameters

t	The thread to queue.
front_of_line	Set to true to put this thread in front of other threads of the same priority, false to put it behind the other threads (normal behavior).

See also: thd_remove_from_runnable

◆ thd_block_now()

int thd_block_now ( irq_context_t * mycxt )

Block the current thread.

Blocks the calling thread and performs a reschedule as if a context switch timer had been executed. This is useful for, e.g., blocking on sync primitives. The param 'mycxt' should point to the calling thread's context block. This is implemented in arch-specific code.

The meaningfulness of the return value depends on whether the unblocker set a return value or not.

Parameters

mycxt The IRQ context of the calling thread.

Returns: Whatever the unblocker deems necessary to return.

◆ thd_by_tid() [1/2]

kthread_t * thd_by_tid ( tid_t tid )

Parameters

tid	The thread ID to retrieve.

Returns: The thread on success, NULL on failure.

◆ thd_by_tid() [2/2]

kthread_t * thd_by_tid ( tid_t tid )

Given a thread ID, locates the thread structure.

Parameters

tid	The thread ID to retrieve.

Returns: The thread on success, NULL on failure.

◆ thd_choose_new()

irq_context_t * thd_choose_new ( void )

Find a new thread to swap in.

This function looks at the state of the system and returns a new thread context to swap in. This is called from thd_block_now() and from the preemptive context switcher. Note that thd_current might be NULL on entering this function, if the caller blocked itself.

It is assumed that by the time this returns, the irq_srt_addr and thd_current will be updated.

Returns: The IRQ context of the thread selected.

◆ thd_create() [1/2]

kthread_t * thd_create	(	bool	detach,
		void (	routine )(void *param),
		void *	param )

This function creates a new kernel thread with default parameters to run the given routine. The thread will terminate and clean up resources when the routine completes if the thread is created detached, otherwise you must join the thread with thd_join() to clean up after it.

Parameters

detach	Set to true to create a detached thread. Set to false to create a joinable thread.
routine	The function to call in the new thread.
param	A parameter to pass to the function called.

Returns: The new thread on success, NULL on failure.

See also: thd_create_ex, thd_destroy

◆ thd_create() [2/2]

kthread_t * thd_create	(	bool	detach,
		void (	routine )(void *param),
		void *	param )

Create a new thread.

This function creates a new kernel thread with default parameters to run the given routine. The thread will terminate and clean up resources when the routine completes if the thread is created detached, otherwise you must join the thread with thd_join() to clean up after it.

Parameters

detach	Set to true to create a detached thread. Set to false to create a joinable thread.
routine	The function to call in the new thread.
param	A parameter to pass to the function called.

Returns: The new thread on success, NULL on failure.

See also: thd_create_ex, thd_destroy

◆ thd_create_ex() [1/2]

kthread_t * thd_create_ex	(	const kthread_attr_t *__RESTRICT	attr,
		void (	routine )(void *param),
		void *	param )

This function creates a new kernel thread with the specified set of parameters to run the given routine.

Parameters

attr	A set of thread attributes for the created thread. Passing NULL will initialize all attributes to their default values.
routine	The function to call in the new thread.
param	A parameter to pass to the function called.

Returns: The new thread on success, NULL on failure.

See also: thd_create, thd_destroy

◆ thd_create_ex() [2/2]

kthread_t * thd_create_ex	(	const kthread_attr_t *__RESTRICT	attr,
		void (	routine )(void *param),
		void *	param )

Create a new thread with the specified set of attributes.

This function creates a new kernel thread with the specified set of parameters to run the given routine.

Parameters

attr	A set of thread attributes for the created thread. Passing NULL will initialize all attributes to their default values.
routine	The function to call in the new thread.
param	A parameter to pass to the function called.

Returns: The new thread on success, NULL on failure.

See also: thd_create, thd_destroy

◆ thd_destroy() [1/2]

int thd_destroy ( kthread_t * thd )

This function kills the given thread, removing it from the execution chain, cleaning up thread-local data and other internal structures. In general, you shouldn't call this function at all.

Warning: You should never call this function on the current thread.

Parameters

thd	The thread to destroy.

Return values

0	On success.

See also: thd_create

◆ thd_destroy() [2/2]

int thd_destroy ( kthread_t * thd )

Brutally kill the given thread.

This function kills the given thread, removing it from the execution chain, cleaning up thread-local data and other internal structures. In general, you shouldn't call this function at all.

Warning: You should never call this function on the current thread.

Parameters

thd	The thread to destroy.

Return values

0	On success.

See also: thd_create

◆ thd_detach() [1/2]

int thd_detach ( kthread_t * thd )

This function switches the specified thread's mode from THD_MODE_JOINABLE to THD_MODE_DETACHED. This will ensure that the thread cleans up all of its internal resources when it exits.

Parameters

thd	The joinable thread to detach.

Returns: 0 on success or less than 0 if the thread is non-existent or already detached.

See also: thd_join()

◆ thd_detach() [2/2]

int thd_detach ( kthread_t * thd )

Detach a joinable thread.

This function switches the specified thread's mode from THD_MODE_JOINABLE to THD_MODE_DETACHED. This will ensure that the thread cleans up all of its internal resources when it exits.

Parameters

thd	The joinable thread to detach.

Returns: 0 on success or less than 0 if the thread is non-existent or already detached.

See also: thd_join()

◆ thd_each() [1/2]

int thd_each	(	int(*	cb )(kthread_t thd, void user_data),
		void *	data )

Parameters

cb	The callback to call for each thread. If a nonzero value is returned, iteration ceases immediately.
data	User data to be passed to the callback

Return values

0	or the first nonzero value returned by `cb`.

See also: thd_pslist

◆ thd_each() [2/2]

int thd_each	(	int(*	cb )(kthread_t thd, void user_data),
		void *	data )

Iterate all threads and call the passed callback for each.

Parameters

cb	The callback to call for each thread. If a nonzero value is returned, iteration ceases immediately.
data	User data to be passed to the callback

Return values

0	or the first nonzero value returned by `cb`.

See also: thd_pslist

◆ thd_exit()

void thd_exit ( void * rv )

Exit the current thread.

This function ends the execution of the current thread, removing it from all execution queues. This function will never return to the thread. Returning from the thread's function is equivalent to calling this function.

Parameters

rv	The return value of the thread.

◆ thd_get_cpu_time() [1/2]

uint64_t thd_get_cpu_time ( kthread_t * thd )

Returns the amount of active CPU time the thread has consumed in nanoseconds.

Warning: The implementation uses perf_cntr_timer_ns() internally when maintaining this CPU time, so disabling or clearing the nanosecond timer will interfere with this time keeping.

Parameters

thd	The thead to retrieve the CPU time for

Return values

Total utilized CPU time in nanoseconds OR 0 if the nanosecond timer of the performance counters has been disturbed.

◆ thd_get_cpu_time() [2/2]

uint64_t thd_get_cpu_time ( kthread_t * thd )

Retrieves the thread's elapsed CPU time.

Returns the amount of active CPU time the thread has consumed in nanoseconds.

Warning: The implementation uses perf_cntr_timer_ns() internally when maintaining this CPU time, so disabling or clearing the nanosecond timer will interfere with this time keeping.

Parameters

thd	The thead to retrieve the CPU time for

Return values

Total utilized CPU time in nanoseconds OR 0 if the nanosecond timer of the performance counters has been disturbed.

◆ thd_get_current() [1/2]

kthread_t * thd_get_current ( void )

Returns: The current thread's structure.

◆ thd_get_current() [2/2]

kthread_t * thd_get_current ( void )

Retrieve the current thread's kthread struct.

Returns: The current thread's structure.

◆ thd_get_errno() [1/2]

int * thd_get_errno ( kthread_t * thd )

This function retrieves a pointer to the errno value for the thread. You should generally just use the errno variable to access this.

Parameters

thd	The thread to retrieve from.

Returns: A pointer to the thread's errno.

◆ thd_get_errno() [2/2]

int * thd_get_errno ( kthread_t * thd )

Retrieve a pointer to the thread errno.

This function retrieves a pointer to the errno value for the thread. You should generally just use the errno variable to access this.

Parameters

thd	The thread to retrieve from.

Returns: A pointer to the thread's errno.

◆ thd_get_hz()

unsigned thd_get_hz ( void )

Fetch the scheduler's current frequency.

Queries the scheduler for its interrupt frequency in hertz.

Returns: Scheduler frequency in hertz.

See also: thd_set_hz(), HZ

◆ thd_get_label() [1/2]

const char * thd_get_label ( kthread_t * thd )

Parameters

thd	The thread to retrieve from.

Returns: The human-readable label of the thread.

See also: thd_set_label

◆ thd_get_label() [2/2]

const char * thd_get_label ( kthread_t * thd )

Retrieve the thread's label.

Parameters

thd	The thread to retrieve from.

Returns: The human-readable label of the thread.

See also: thd_set_label

◆ thd_get_mode()

kthread_mode_t thd_get_mode ( void )

Fetch the current threading mode.

With preemptive threading being the only mode.

Deprecated: This is now deprecated.

Returns: The current mode of the threading system.

See also: thd_set_mode

◆ thd_get_pwd() [1/2]

const char * thd_get_pwd ( kthread_t * thd )

This function retrieves the working directory of a thread. Generally, you will want to use either fs_getwd() or one of the standard C functions for doing this, but this is here in case you need it when the thread isn't active for some reason.

Parameters

thd	The thread to retrieve from.

Returns: The thread's working directory.

See also: thd_set_pd

◆ thd_get_pwd() [2/2]

const char * thd_get_pwd ( kthread_t * thd )

Retrieve the thread's current working directory.

This function retrieves the working directory of a thread. Generally, you will want to use either fs_getwd() or one of the standard C functions for doing this, but this is here in case you need it when the thread isn't active for some reason.

Parameters

thd	The thread to retrieve from.

Returns: The thread's working directory.

See also: thd_set_pd

◆ thd_get_reent() [1/2]

struct _reent * thd_get_reent ( kthread_t * thd )

This function is used to retrieve some internal state that is used by newlib to provide a reentrant libc.

Parameters

thd	The thread to retrieve from.

Returns: The thread's reent struct.

◆ thd_get_reent() [2/2]

struct _reent * thd_get_reent ( kthread_t * thd )

Retrieve a pointer to the thread reent struct.

This function is used to retrieve some internal state that is used by newlib to provide a reentrant libc.

Parameters

thd	The thread to retrieve from.

Returns: The thread's reent struct.

◆ thd_join() [1/2]

int thd_join	(	kthread_t *	thd,
		void **	value_ptr )

This function "joins" a joinable thread. This means effectively that the calling thread blocks until the speified thread completes execution. It is invalid to join a detached thread, only joinable threads may be joined.

Parameters

thd	The joinable thread to join.
value_ptr	A pointer to storage for the thread's return value, or NULL if you don't care about it.

Returns: 0 on success, or less than 0 if the thread is non-existent or not joinable.

See also: thd_detach

◆ thd_join() [2/2]

int thd_join	(	kthread_t *	thd,
		void **	value_ptr )

Wait for a thread to exit.

This function "joins" a joinable thread. This means effectively that the calling thread blocks until the speified thread completes execution. It is invalid to join a detached thread, only joinable threads may be joined.

Parameters

thd	The joinable thread to join.
value_ptr	A pointer to storage for the thread's return value, or NULL if you don't care about it.

Returns: 0 on success, or less than 0 if the thread is non-existent or not joinable.

See also: thd_detach

◆ thd_pass()

void thd_pass ( void )

Throw away the current thread's timeslice.

This function manually yields the current thread's timeslice to the system, forcing a reschedule to occur.

◆ thd_pslist()

int thd_pslist ( int(* pf )(const char *fmt,...) )

Print a list of all threads using the given print function.

Parameters

pf	The printf-like function to print with.

Return values

0	On success.

See also: thd_pslist_queue

◆ thd_pslist_queue()

int thd_pslist_queue ( int(* pf )(const char *fmt,...) )

Print a list of all queued threads using the given print function.

Parameters

pf	The printf-like function to print with.

Return values

0	On success.

See also: thd_pslist

◆ thd_remove_from_runnable() [1/2]

int thd_remove_from_runnable ( kthread_t * thd )

This function removes a thread from the runnable queue, if it is currently in that queue. Generally, you shouldn't have to do this manually, as waiting on synchronization primitives and the like will do this for you if needed.

Parameters

thd	The thread to remove from the runnable queue.

Return values

0	On success, or if the thread isn't runnable.

See also: thd_add_to_runnable

◆ thd_remove_from_runnable() [2/2]

int thd_remove_from_runnable ( kthread_t * thd )

Removes a thread from the runnable queue, if it's there.

This function removes a thread from the runnable queue, if it is currently in that queue. Generally, you shouldn't have to do this manually, as waiting on synchronization primitives and the like will do this for you if needed.

Parameters

thd	The thread to remove from the runnable queue.

Return values

0	On success, or if the thread isn't runnable.

See also: thd_add_to_runnable

◆ thd_schedule()

void thd_schedule	(	bool	front_of_line,
		uint64_t	now )

Force a thread reschedule.

This function is the thread scheduler, and is generally called from a timer interrupt. You will most likely never have a reason to call this function directly.

For most cases, you'll want to set front_of_line to zero, but read the comments in kernel/thread/thread.c for more info, especially if you need to guarantee low latencies. This function just updates irq_srt_addr and thd_current. Set 'now' to non-zero if you want to use a particular system time for checking timeouts.

Parameters

front_of_line	Set to false, unless you have a good reason not to.
now	Set to 0, unless you have a good reason not to.

See also: thd_schedule_next

◆ thd_schedule_next() [1/2]

void thd_schedule_next ( kthread_t * thd )

This function promotes the given thread to be the next one that will be swapped in by the scheduler. This function is only callable inside an interrupt context (it simply returns otherwise).

Parameters

thd	The thread to schedule next.

◆ thd_schedule_next() [2/2]

void thd_schedule_next ( kthread_t * thd )

Force a given thread to the front of the queue.

This function promotes the given thread to be the next one that will be swapped in by the scheduler. This function is only callable inside an interrupt context (it simply returns otherwise).

Parameters

thd	The thread to schedule next.

◆ thd_set_hz()

int thd_set_hz ( unsigned int hertz )

Set the scheduler's frequency.

Sets the frequency of the scheduler interrupts in hertz.

Parameters

hertz The new frequency in hertz (1-1000)

Return values

0	The frequency was updated successfully.
-1	`hertz` is invalid.

See also: thd_get_hz(), HZ

◆ thd_set_label() [1/2]

void thd_set_label	(	kthread_t *	thd,
		const char *__RESTRICT	label )

This function sets the label of a thread, which is simply a human-readable string that is used to identify the thread. These labels aren't used for anything internally, and you can give them any label you want. These are mainly seen in the printouts from thd_pslist() or thd_pslist_queue().

Parameters

thd	The thread to set the label of.
label	The string to set as the label.

See also: thd_get_label

◆ thd_set_label() [2/2]

void thd_set_label	(	kthread_t *	thd,
		const char *__RESTRICT	label )

Set the thread's label.

This function sets the label of a thread, which is simply a human-readable string that is used to identify the thread. These labels aren't used for anything internally, and you can give them any label you want. These are mainly seen in the printouts from thd_pslist() or thd_pslist_queue().

Parameters

thd	The thread to set the label of.
label	The string to set as the label.

See also: thd_get_label

◆ thd_set_mode()

int thd_set_mode ( kthread_mode_t mode )

Change threading modes.

This function changes the current threading mode of the system. With preemptive threading being the only mode.

Deprecated: This is now deprecated

Parameters

mode	One of the THD_MODE values.

Returns: The old mode of the threading system.

See also: thd_get_mode

◆ thd_set_prio() [1/2]

int thd_set_prio	(	kthread_t *	thd,
		prio_t	prio )

This function is used to change the priority value of a thread. If the thread is scheduled already, it will be rescheduled with the new priority value.

Parameters

thd	The thread to change the priority of.
prio	The priority value to assign to the thread.

Return values

0	On success.
-1	thd is NULL.
-2	prio requested was out of range.

◆ thd_set_prio() [2/2]

int thd_set_prio	(	kthread_t *	thd,
		prio_t	prio )

Set a thread's priority value.

This function is used to change the priority value of a thread. If the thread is scheduled already, it will be rescheduled with the new priority value.

Parameters

thd	The thread to change the priority of.
prio	The priority value to assign to the thread.

Return values

0	On success.
-1	thd is NULL.
-2	prio requested was out of range.

◆ thd_set_pwd() [1/2]

void thd_set_pwd	(	kthread_t *	thd,
		const char *__RESTRICT	pwd )

This function will set the working directory of a thread. Generally, you will want to use either fs_chdir() or the standard C chdir() function to do this, but this is here in case you need to do it while the thread isn't active for some reason.

Parameters

thd	The thread to set the working directory of.
pwd	The directory to set as active.

See also: thd_get_pwd

◆ thd_set_pwd() [2/2]

void thd_set_pwd	(	kthread_t *	thd,
		const char *__RESTRICT	pwd )

Set the thread's current working directory.

This function will set the working directory of a thread. Generally, you will want to use either fs_chdir() or the standard C chdir() function to do this, but this is here in case you need to do it while the thread isn't active for some reason.

Parameters

thd	The thread to set the working directory of.
pwd	The directory to set as active.

See also: thd_get_pwd

◆ thd_sleep()

void thd_sleep ( unsigned ms )

Sleep for a given number of milliseconds.

This function puts the current thread to sleep for the specified amount of time. The thread will be removed from the runnable queue until the given number of milliseconds passes. That is to say that the thread will sleep for at least the given number of milliseconds. If another thread is running, it will likely sleep longer.

Note: When ms is given a value of 0, this is equivalent to thd_pass().

Parameters

ms	The number of milliseconds to sleep.

Files

Data Structures

Macros

Typedefs

Enumerations

Functions

Thread flag values

Detailed Description

Macro Definition Documentation

◆ KOS_PID

◆ KTHREAD_LABEL_SIZE

◆ KTHREAD_PWD_SIZE

◆ PRIO_DEFAULT

◆ PRIO_MAX

◆ THD_DEFAULTS

◆ THD_DETACHED

◆ THD_OWNS_STACK

◆ THD_QUEUED

◆ THD_USER

Typedef Documentation

◆ kthread_flags_t

Enumeration Type Documentation

◆ kthread_mode_t

◆ kthread_state_t

Function Documentation

◆ thd_add_to_runnable() [1/2]

◆ thd_add_to_runnable() [2/2]

◆ thd_block_now()

◆ thd_by_tid() [1/2]

◆ thd_by_tid() [2/2]

◆ thd_choose_new()

◆ thd_create() [1/2]

◆ thd_create() [2/2]

◆ thd_create_ex() [1/2]

◆ thd_create_ex() [2/2]

◆ thd_destroy() [1/2]

◆ thd_destroy() [2/2]

◆ thd_detach() [1/2]

◆ thd_detach() [2/2]

◆ thd_each() [1/2]

◆ thd_each() [2/2]

◆ thd_exit()

◆ thd_get_cpu_time() [1/2]

◆ thd_get_cpu_time() [2/2]

◆ thd_get_current() [1/2]

◆ thd_get_current() [2/2]

◆ thd_get_errno() [1/2]

◆ thd_get_errno() [2/2]

◆ thd_get_hz()

◆ thd_get_label() [1/2]

◆ thd_get_label() [2/2]

◆ thd_get_mode()

◆ thd_get_pwd() [1/2]

◆ thd_get_pwd() [2/2]

◆ thd_get_reent() [1/2]

◆ thd_get_reent() [2/2]

◆ thd_join() [1/2]

◆ thd_join() [2/2]

◆ thd_pass()

◆ thd_pslist()

◆ thd_pslist_queue()

◆ thd_remove_from_runnable() [1/2]

◆ thd_remove_from_runnable() [2/2]

◆ thd_schedule()

◆ thd_schedule_next() [1/2]

◆ thd_schedule_next() [2/2]

◆ thd_set_hz()

◆ thd_set_label() [1/2]

◆ thd_set_label() [2/2]

◆ thd_set_mode()

◆ thd_set_prio() [1/2]

◆ thd_set_prio() [2/2]

◆ thd_set_pwd() [1/2]

◆ thd_set_pwd() [2/2]

◆ thd_sleep()