include/uapi/linux/time.h

Source file repositories/reference/linux-study-clean/include/uapi/linux/time.h

File Facts

System
Linux kernel
Corpus path
include/uapi/linux/time.h
Extension
.h
Size
2207 bytes
Lines
87
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct timespec {
	__kernel_old_time_t	tv_sec;		/* seconds */
	long			tv_nsec;	/* nanoseconds */
};
#endif

struct timeval {
	__kernel_old_time_t	tv_sec;		/* seconds */
	__kernel_suseconds_t	tv_usec;	/* microseconds */
};

struct itimerspec {
	struct timespec it_interval;/* timer period */
	struct timespec it_value;	/* timer expiration */
};

struct itimerval {
	struct timeval it_interval;/* timer interval */
	struct timeval it_value;	/* current value */
};
#endif

struct timezone {
	int	tz_minuteswest;	/* minutes west of Greenwich */
	int	tz_dsttime;	/* type of dst correction */
};

/*
 * Names of the interval timers, and structure
 * defining a timer setting:
 */
#define	ITIMER_REAL		0
#define	ITIMER_VIRTUAL		1
#define	ITIMER_PROF		2

/*
 * The IDs of the various system clocks (for POSIX.1b interval timers):
 */
#define CLOCK_REALTIME			0
#define CLOCK_MONOTONIC			1
#define CLOCK_PROCESS_CPUTIME_ID	2
#define CLOCK_THREAD_CPUTIME_ID		3
#define CLOCK_MONOTONIC_RAW		4
#define CLOCK_REALTIME_COARSE		5
#define CLOCK_MONOTONIC_COARSE		6
#define CLOCK_BOOTTIME			7
#define CLOCK_REALTIME_ALARM		8
#define CLOCK_BOOTTIME_ALARM		9
/*
 * The driver implementing this got removed. The clock ID is kept as a
 * place holder. Do not reuse!
 */
#define CLOCK_SGI_CYCLE			10
#define CLOCK_TAI			11

#define MAX_CLOCKS			16

/*
 * AUX clock support. AUXiliary clocks are dynamically configured by
 * enabling a clock ID. These clock can be steered independently of the
 * core timekeeper. The kernel can support up to 8 auxiliary clocks, but
 * the actual limit depends on eventual architecture constraints vs. VDSO.
 */
#define CLOCK_AUX			MAX_CLOCKS
#define MAX_AUX_CLOCKS			8
#define CLOCK_AUX_LAST			(CLOCK_AUX + MAX_AUX_CLOCKS - 1)

#define CLOCKS_MASK			(CLOCK_REALTIME | CLOCK_MONOTONIC)
#define CLOCKS_MONO			CLOCK_MONOTONIC

/*
 * The various flags for setting POSIX.1b interval timers:
 */
#define TIMER_ABSTIME			0x01

#endif /* _UAPI_LINUX_TIME_H */

Annotation

Implementation Notes