Time subsystem

System time. More...

Data Structures
struct	sys_time_source_t
	Timer system source. More...

Macros
#define	SYS_TIME_MAX_SOURCES   8
	Maximum amount of system timer sources.

Functions
uint64_t	sys_time_register_source (const sys_time_source_t *source)
	Register a system timer source.
void	sys_time_unregister_source (const sys_time_source_t *source)
	Unregister a system timer source.
clock_t	sys_time_uptime (void)
	Time since boot.
time_t	sys_time_unix_epoch (void)
	The unix epoch.
void	sys_time_wait (clock_t nanoseconds)
	Wait for a specified number of nanoseconds.

Detailed Description

System time.

The sys time subsystem is responsible for providing a consistent system wide time keeping.

System wide time is provided via "system time sources", which are provided in modules. Each source registers itself with a estimate of its precision, the timer subsystem then chooses the source with the highest precision as the system time source.

Macro Definition Documentation

SYS_TIME_MAX_SOURCES

#define SYS_TIME_MAX_SOURCES   8

Maximum amount of system timer sources.

Definition at line 28 of file sys_time.h.

Function Documentation

sys_time_register_source()

uint64_t sys_time_register_source

(

const sys_time_source_t *

source

)

Register a system timer source.

Parameters

source

The timer source to register.

Returns

On success, 0. On failure, ERR and errno is set.

Definition at line 35 of file sys_time.c.

References bestSource, EINVAL, ENOSPC, ERR, errno, LOG_INFO, sys_time_source_t::name, NULL, sys_time_source_t::precision, sys_time_source_t::read, rwlock_write_acquire(), rwlock_write_release(), source, sourceCount, sources, sourcesLock, and SYS_TIME_MAX_SOURCES.

Referenced by hpet_init().

sys_time_unix_epoch()

time_t sys_time_unix_epoch

(

void

)

The unix epoch.

Returns

The amount of seconds since the unix epoch.

Definition at line 117 of file sys_time.c.

References bootEpoch, bootEpochInitialized, CLOCKS_PER_SEC, sys_time_uptime(), and timer_boot_epoch_init().

Referenced by inode_new(), inode_notify_access(), inode_notify_change(), inode_notify_modify(), and SYSCALL_DEFINE().

sys_time_unregister_source()

void sys_time_unregister_source

(

const sys_time_source_t *

source

)

Unregister a system timer source.

Parameters

source

The timer source to unregister.

Definition at line 67 of file sys_time.c.

References bestSource, LOG_INFO, memmove(), sys_time_source_t::name, NULL, panic(), rwlock_write_acquire(), rwlock_write_release(), source, sourceCount, sources, and sourcesLock.

Referenced by hpet_deinit().

sys_time_uptime()

clock_t sys_time_uptime

(

void

)

Time since boot.

Returns

The time in nanoseconds since boot.

Definition at line 106 of file sys_time.c.

References bestSource, NULL, sys_time_source_t::read, RWLOCK_READ_SCOPE, and sourcesLock.

Referenced by aml_def_timer_read(), hpet_timer_handler(), kbd_push(), key_share(), key_timer_handler(), log_print_header(), mouse_push(), mutex_acquire_timeout(), perf_cpu_read(), perf_interrupt_begin(), perf_interrupt_end(), perf_process_ctx_init(), perf_syscall_begin(), perf_syscall_end(), process_kill(), ps2_wait_until_clear(), ps2_wait_until_set(), rand_gen_fallback(), sched_compute_time_slice(), sched_invoke(), sched_push(), sched_push_new_thread(), space_tlb_shootdown(), sys_time_unix_epoch(), sys_time_wait(), SYSCALL_DEFINE(), SYSCALL_DEFINE(), vfs_poll(), wait_block_setup(), and wait_timer_handler().

sys_time_wait()

void sys_time_wait

(

clock_t

nanoseconds

)

Wait for a specified number of nanoseconds.

This function uses a busy-wait loop, making it highly CPU inefficient, but its useful during early initialization or when you are unable to block the current thread.

Parameters

nanoseconds

The number of nanoseconds to wait

Definition at line 127 of file sys_time.c.

References NULL, panic(), start(), and sys_time_uptime().

Referenced by apic_timer_ticks_per_ns(), ps2_device_init(), ps2_drain(), trampoline_send_startup_ipi(), and trampoline_wait_ready().