time.h File Reference

#include <stdint.h>
#include "rcutils/macros.h"
#include "rcutils/types.h"
#include "rcutils/visibility_control.h"

Include dependency graph for time.h:

Go to the source code of this file.

Macros
#define	RCUTILS_S_TO_NS(seconds)   (seconds * (1000 * 1000 * 1000))
	Convenience macro to convert seconds to nanoseconds. More...
#define	RCUTILS_MS_TO_NS(milliseconds)   (milliseconds * (1000 * 1000))
	Convenience macro to convert milliseconds to nanoseconds. More...
#define	RCUTILS_US_TO_NS(microseconds)   (microseconds * 1000)
	Convenience macro to convert microseconds to nanoseconds. More...
#define	RCUTILS_NS_TO_S(nanoseconds)   (nanoseconds / (1000 * 1000 * 1000))
	Convenience macro to convert nanoseconds to seconds. More...
#define	RCUTILS_NS_TO_MS(nanoseconds)   (nanoseconds / (1000 * 1000))
	Convenience macro to convert nanoseconds to milliseconds. More...
#define	RCUTILS_NS_TO_US(nanoseconds)   (nanoseconds / 1000)
	Convenience macro to convert nanoseconds to microseconds. More...

Typedefs
typedef uint64_t	rcutils_time_point_value_t
	A single point in time, measured in nanoseconds since the Unix epoch. More...
typedef int64_t	rcutils_duration_value_t
	A duration of time, measured in nanoseconds. More...

Functions
rcutils_ret_t	rcutils_system_time_now (rcutils_time_point_value_t *now)
rcutils_ret_t	rcutils_steady_time_now (rcutils_time_point_value_t *now)
	Retrieve the current time as a rcutils_time_point_value_t object. More...

Macro Definition Documentation

#define RCUTILS_S_TO_NS

(

seconds

)

(seconds * (1000 * 1000 * 1000))

Convenience macro to convert seconds to nanoseconds.

#define RCUTILS_MS_TO_NS

(

milliseconds

)

(milliseconds * (1000 * 1000))

Convenience macro to convert milliseconds to nanoseconds.

#define RCUTILS_US_TO_NS

(

microseconds

)

(microseconds * 1000)

Convenience macro to convert microseconds to nanoseconds.

#define RCUTILS_NS_TO_S

(

nanoseconds

)

(nanoseconds / (1000 * 1000 * 1000))

Convenience macro to convert nanoseconds to seconds.

#define RCUTILS_NS_TO_MS

(

nanoseconds

)

(nanoseconds / (1000 * 1000))

Convenience macro to convert nanoseconds to milliseconds.

#define RCUTILS_NS_TO_US

(

nanoseconds

)

(nanoseconds / 1000)

Convenience macro to convert nanoseconds to microseconds.

Typedef Documentation

typedef uint64_t rcutils_time_point_value_t

A single point in time, measured in nanoseconds since the Unix epoch.

typedef int64_t rcutils_duration_value_t

A duration of time, measured in nanoseconds.

Function Documentation

rcutils_ret_t rcutils_system_time_now

(

rcutils_time_point_value_t *

now

)

This function returns the time from a system clock. The closest equivalent would be to std::chrono::system_clock::now();

The resolution (e.g. nanoseconds vs microseconds) is not guaranteed.

The now argument must point to an allocated rcutils_time_point_value_t object, as the result is copied into this variable.

---

Attribute	Adherence
Allocates Memory	No
Thread-Safe	Yes
Uses Atomics	No
Lock-Free	Yes

Parameters

[out]

now

a datafield in which the current time is stored

Returns

RCUTILS_RET_OK if the current time was successfully obtained, or

RCUTILS_RET_INVALID_ARGUMENT if any arguments are invalid, or

RCUTILS_RET_ERROR an unspecified error occur.

rcutils_ret_t rcutils_steady_time_now

(

rcutils_time_point_value_t *

now

)

Retrieve the current time as a rcutils_time_point_value_t object.

This function returns the time from a monotonically increasing clock. The closest equivalent would be to std::chrono::steady_clock::now();

The resolution (e.g. nanoseconds vs microseconds) is not guaranteed.

The now argument must point to an allocated rcutils_time_point_value_t object, as the result is copied into this variable.

---

Attribute	Adherence
Allocates Memory	No
Thread-Safe	Yes
Uses Atomics	No
Lock-Free	Yes

Parameters

[out]

now

a struct in which the current time is stored

Returns

RCUTILS_RET_OK if the current time was successfully obtained, or

RCUTILS_RET_INVALID_ARGUMENT if any arguments are invalid, or

RCUTILS_RET_ERROR an unspecified error occur.