Other Utilities

Other Utilities, such as NDDS_Utility_spin. More...

Functions
void	NDDS_Utility_sleep (const struct DDS_Duration_t *durationIn)
	Block the calling thread for the specified duration. More...
void	NDDS_Utility_spin (DDS_UnsignedLongLong spinCount)
	Performs the spin operation as many times as indicated. More...
DDS_UnsignedLongLong	NDDS_Utility_get_spin_per_microsecond (void)
	Returns the number of spin operations to perform to wait 1 microsecond. More...

Detailed Description

Other Utilities, such as NDDS_Utility_spin.

Function Documentation

NDDS_Utility_sleep()

void NDDS_Utility_sleep

(

const struct DDS_Duration_t *

durationIn

)

Block the calling thread for the specified duration.

Note that the achievable resolution of sleep is OS-dependent. That is, do not assume that you can sleep for 1 nanosecond just because you can specify a 1-nanosecond sleep duration via the API. The sleep resolution on most operating systems is usually 10 ms or greater.

Parameters

durationIn

<<in>> Sleep duration. Cannot be NULL.

MT Safety:

safe

Examples

HelloWorld_publisher.c, and HelloWorld_subscriber.c.

NDDS_Utility_spin()

void NDDS_Utility_spin

(

DDS_UnsignedLongLong

spinCount

)

Performs the spin operation as many times as indicated.

Spinning is the action of performing useless operations in a for loop in order to actively wait some time without yielding the CPU. Given that the resolution of sleep is in the order of ms, you can use this utility to wait times in the order of microseconds. To properly use this functionality, it is useful to measure previously the number of spin operations needed to wait the equivalent to microsecond (using the utility get_spin_per_microsecond) and then compute the corresponding spin count desired.

Parameters

spinCount

<<in>> Number of spin operations to perform.

NDDS_Utility_get_spin_per_microsecond()

DDS_UnsignedLongLong NDDS_Utility_get_spin_per_microsecond

(

void

)

Returns the number of spin operations to perform to wait 1 microsecond.

This utility can be used to measure how many spin operations must be performed to wait 1 microsecond. Since the time that it takes the CPU to perform 1 spin operation depends on the CPU frequency, it is recommended to use this utility before using spin().

Returns

Number of spin operations to wait 1 microsecond.

See also

NDDS_Utility_spin